Posts Tagged Azure

Architecting Cloud-Optimized Apps with AKS (Azure’s Managed Kubernetes), Azure Service Bus, and Cosmos DB

An earlier post, Eventual Consistency: Decoupling Microservices with Spring AMQP and RabbitMQ, demonstrated the use of a message-based, event-driven, decoupled architectural approach for communications between microservices, using Spring AMQP and RabbitMQ. This distributed computing model is known as eventual consistency. To paraphrase microservices.io, ‘using an event-driven, eventually consistent approach, each service publishes an event whenever it updates its data. Other services subscribe to events. When an event is received, a service (subscriber) updates its data.

That earlier post illustrated a fairly simple example application, the Voter API, consisting of a set of three Spring Boot microservices backed by MongoDB and RabbitMQ, and fronted by an API Gateway built with HAProxy. All API components were containerized using Docker and designed for use with Docker CE for AWS as the Container-as-a-Service (CaaS) platform.

Optimizing for Kubernetes on Azure

This post will demonstrate how a modern application, such as the Voter API, is optimized for Kubernetes in the Cloud (Kubernetes-as-a-Service), in this case, AKS, Azure’s new public preview of Managed Kubernetes for Azure Container Service. According to Microsoft, the goal of AKS is to simplify the deployment, management, and operations of Kubernetes. I wrote about AKS in detail, in my last post, First Impressions of AKS, Azure’s New Managed Kubernetes Container Service.

In addition to migrating to AKS, the Voter API will take advantage of additional enterprise-grade Azure’s resources, including Azure’s Service Bus and Cosmos DB, replacements for the Voter API’s RabbitMQ and MongoDB. There are several architectural options for the Voter API’s messaging and NoSQL data source requirements when moving to Azure.

  1. Keep Dockerized RabbitMQ and MongoDB – Easy to deploy to Kubernetes, but not easily scalable, highly-available, or manageable. Would require storage optimized Azure VMs for nodes, node affinity, and persistent storage for data.
  2. Replace with Cloud-based Non-Azure Equivalents – Use SaaS-based equivalents, such as CloudAMQP (RabbitMQ-as-a-Service) and MongoDB Atlas, which will provide scalability, high-availability, and manageability.
  3. Replace with Azure Service Bus and Cosmos DB – Provides all the advantages of  SaaS-based equivalents, and additionally as Azure resources, benefits from being in the Azure Cloud alongside AKS.

Source Code

The Kubernetes resource files and deployment scripts used in this post are all available on GitHub. This is the only project you need to clone to reproduce the AKS example in this post.

git clone \
  --branch master --single-branch --depth 1 --no-tags \
  https://github.com/garystafford/azure-aks-sb-cosmosdb-demo.git

The Docker images for the three Spring microservices deployed to AKS, Voter, Candidate, and Election, are available on Docker Hub. Optionally, the source code, including Dockerfiles, for the Voter, Candidate, and Election microservices, as well as the Voter Client are available on GitHub, in the kub-aks branch.

git clone \
  --branch kub-aks --single-branch --depth 1 --no-tags \
  https://github.com/garystafford/candidate-service.git

git clone \
  --branch kub-aks --single-branch --depth 1 --no-tags \
  https://github.com/garystafford/election-service.git

git clone \
  --branch kub-aks --single-branch --depth 1 --no-tags \
  https://github.com/garystafford/voter-service.git

git clone \
  --branch kub-aks --single-branch --depth 1 --no-tags \
  https://github.com/garystafford/voter-client.git

Azure Service Bus

To demonstrate the capabilities of Azure’s Service Bus, the Voter API’s Spring microservice’s source code has been re-written to work with Azure Service Bus instead of RabbitMQ. A future post will explore the microservice’s messaging code. It is more likely that a large application, written specifically for a technology that is easily portable such as RabbitMQ or MongoDB, would likely remain on that technology, even if the application was lifted and shifted to the Cloud or moved between Cloud Service Providers (CSPs). Something important to keep in mind when choosing modern technologies – portability.

Service Bus is Azure’s reliable cloud Messaging-as-a-Service (MaaS). Service Bus is an original Azure resource offering, available for several years. The core components of the Service Bus messaging infrastructure are queues, topics, and subscriptions. According to Microsoft, ‘the primary difference is that topics support publish/subscribe capabilities that can be used for sophisticated content-based routing and delivery logic, including sending to multiple recipients.

Since the three Voter API’s microservices are not required to produce messages for more than one other service consumer, Service Bus queues are sufficient, as opposed to a pub/sub model using Service Bus topics.

Cosmos DB

Cosmos DB, Microsoft’s globally distributed, multi-model database, offers throughput, latency, availability, and consistency guarantees with comprehensive service level agreements (SLAs). Ideal for the Voter API, Cosmos DB supports MongoDB’s data models through the MongoDB API, a MongoDB database service built on top of Cosmos DB. The MongoDB API is compatible with existing MongoDB libraries, drivers, tools, and applications. Therefore, there are no code changes required to convert the Voter API from MongoDB to Cosmos DB. I simply had to change the database connection string.

NGINX Ingress Controller

Although the Voter API’s HAProxy-based API Gateway could be deployed to AKS, it is not optimal for Kubernetes. Instead, the Voter API will use an NGINX-based Ingress Controller. NGINX will serve as an API Gateway, as HAProxy did, previously.

According to NGINX, ‘an Ingress is a Kubernetes resource that lets you configure an HTTP load balancer for your Kubernetes services. Such a load balancer usually exposes your services to clients outside of your Kubernetes cluster.

An Ingress resource requires an Ingress Controller to function. Continuing from NGINX, ‘an Ingress Controller is an application that monitors Ingress resources via the Kubernetes API and updates the configuration of a load balancer in case of any changes. Different load balancers require different Ingress controller implementations. In the case of software load balancers, such as NGINX, an Ingress controller is deployed in a pod along with a load balancer.

There are currently two NGINX-based Ingress Controllers available, one from Kubernetes and one directly from NGINX. Both being equal, for this post, I chose the Kubernetes version, without RBAC (Kubernetes offers a version with and without RBAC). RBAC should always be used for actual cluster security. There are several advantages of using either version of the NGINX Ingress Controller for Kubernetes, including Layer 4 TCP and UDP and Layer 7 HTTP load balancing, reverse proxying, ease of SSL termination, dynamically-configurable path-based rules, and support for multiple hostnames.

Azure Web App

Lastly, the Voter Client application, not really part of the Voter API, but useful for demonstration purposes, will be converted from a containerized application to an Azure Web App. Since it is not part of the Voter API, separating the Client application from AKS makes better architectural sense. Web Apps are a powerful, richly-featured, yet incredibly simple way to host applications and services on Azure. For more information on using Azure Web Apps, read my recent post, Developing Applications for the Cloud with Azure App Services and MongoDB Atlas.

Revised Component Architecture

Below is a simplified component diagram of the new architecture, including Azure Service Bus, Cosmos DB, and the NGINX Ingress Controller. The new architecture looks similar to the previous architecture, but as you will see, it is actually very different.

AKS-r8.png

Process Flow

To understand the role of each API component, let’s look at one of the event-driven, decoupled process flows, the creation of a new election candidate. In the simplified flow diagram below, an API consumer executes an HTTP POST request containing the new candidate object as JSON. The Candidate microservice receives the HTTP request and creates a new document in the Cosmos DB Voter database. A Spring RepositoryEventHandler within the Candidate microservice responds to the document creation and publishes a Create Candidate event message, containing the new candidate object as JSON, to the Azure Service Bus Candidate Queue.

Candidate_Producer

Independently, the Voter microservice is listening to the Candidate Queue. Whenever a new message is produced by the Candidate microservice, the Voter microservice retrieves the message off the queue. The Voter microservice then transforms the new candidate object contained in the incoming message to its own candidate data model and creates a new document in its own Voter database.

Voter_Consumer

The same process flows exist between the Election and the Candidate microservices. The Candidate microservice maintains current elections in its database, which are retrieved from the Election queue.

Data Models

It is useful to understand, the Candidate microservice’s candidate domain model is not necessarily identical to the Voter microservice’s candidate domain model. Each microservice may choose to maintain its own representation of a vote, a candidate, and an election. The Voter service transforms the new candidate object in the incoming message based on its own needs. In this case, the Voter microservice is only interested in a subset of the total fields in the Candidate microservice’s model. This is the beauty of decoupling microservices, their domain models, and their datastores.

Other Events

The versions of the Voter API microservices used for this post only support Election Created events and Candidate Created events. They do not handle Delete or Update events, which would be necessary to be fully functional. For example, if a candidate withdraws from an election, the Voter service would need to be notified so no one places votes for that candidate. This would normally happen through a Candidate Delete or Candidate Update event.

Provisioning Azure Service Bus

First, the Azure Service Bus is provisioned. Provisioning the Service Bus may be accomplished using several different methods, including manually using the Azure Portal or programmatically using Azure Resource Manager (ARM) with PowerShell or Terraform. I chose to provision the Azure Service Bus and the two queues using the Azure Portal for expediency. I chose the Basic Service Bus Tier of service, of which there are three tiers, Basic, Standard, and Premium.

Azure_006_Full_ServiceBus

The application requires two queues, the candidate.queue, and the election.queue.

Azure_008_ServiceBus

Provisioning Cosmos DB

Next, Cosmos DB is provisioned. Like Azure Service Bus, Cosmos DB may be provisioned using several methods, including manually using the Azure Portal, programmatically using Azure Resource Manager (ARM) with PowerShell or Terraform, or using the Azure CLI, which was my choice.

az cosmosdb create \
  --name cosmosdb_instance_name_goes_here \
  --resource-group resource_group_name_goes_here \
  --location "East US=0" \
  --kind MongoDB

The post’s Cosmos DB instance exists within the single East US Region, with no failover. In a real Production environment, you would configure Cosmos DB with multi-region failover. I chose MongoDB as the type of Cosmos DB database account to create. The allowed values are GlobalDocumentDB, MongoDB, Parse. All other settings were left to the default values.

The three Spring microservices each have their own database. You do not have to create the databases in advance of consuming the Voter API. The databases and the database collections will be automatically created when new documents are first inserted by the microservices. Below, the three databases and their collections have been created and populated with documents.

Azure_001_CosmosDB

The GitHub project repository also contains three shell scripts to generate sample vote, candidate, and election documents. The scripts will delete any previous documents from the database collections and generate new sets of sample documents. To use, you will have to update the scripts with your own Voter API URL.

AKS_012_AddVotes2

MongoDB Aggregation Pipeline

Each of the three Spring microservices uses Spring Data MongoDB, which takes advantage of MongoDB’s Aggregation Framework. According to MongoDB, ‘the aggregation framework is modeled on the concept of data processing pipelines. Documents enter a multi-stage pipeline that transforms the documents into an aggregated result.’ Below is an example of aggregation from the Candidate microservice’s VoterContoller class.

Aggregation aggregation = Aggregation.newAggregation(
    match(Criteria.where("election").is(election)),
    group("candidate").count().as("votes"),
    project("votes").and("candidate").previousOperation(),
    sort(Sort.Direction.DESC, "votes")
);

To use MongoDB’s aggregation framework with Cosmos DB, it is currently necessary to activate the MongoDB Aggregation Pipeline Preview Feature of Cosmos DB. The feature can be activated from the Azure Portal, as shown below.

Azure_002_CosmosDB

Cosmos DB Emulator

Be warned, Cosmos DB can be very expensive, even without database traffic or any Production-grade bells and whistles. Be careful when spinning up instances on Azure for learning purposes, the cost adds up quickly! In less than ten days, while writing this post, my cost was almost US$100 for the Voter API’s Cosmos DB instance.

I strongly recommend downloading the free Azure Cosmos DB Emulator to develop and test applications from your local machine. Although certainly not as convenient, it will save you the cost of developing for Cosmos DB directly on Azure.

With Cosmos DB, you pay for reserved throughput provisioned and data stored in containers (a collection of documents or a table or a graph). Yes, that’s right, Azure charges you per MongoDB collection, not even per database. Azure Cosmos DB’s current pricing model seems less than ideal for microservice architectures, each with their own database instance.

By default the reserved throughput, billed as Request Units (RU) per second or RU/s, is set to 1,000 RU/s per collection. For development and testing, you can reduce each collection to a minimum of 400 RU/s. The Voter API creates five collections at 1,000 RU/s or 5,000 RU/s total. Reducing this to a total of 2,000 RU/s makes Cosmos DB marginally more affordable to explore.

Azure_003_CosmosDB.PNG

Building the AKS Cluster

An existing Azure Resource Group is required for AKS. I chose to use the latest available version of Kubernetes, 1.8.2.

# login to azure
az login \
  --username your_username  \
  --password your_password

# create resource group
az group create \
  --resource-group resource_group_name_goes_here \
  --location eastus

# create aks cluster
az aks create \
  --name cluser_name_goes_here \
  --resource-group resource_group_name_goes_here \
  --ssh-key-value path_to_your_public_key \
  --kubernetes-version 1.8.2

# get credentials to access aks cluster
az aks get-credentials \
  --name cluser_name_goes_here \
  --resource-group resource_group_name_goes_here

# display cluster's worker nodes
kubectl get nodes --output=wide

By default, AKS will provision a three-node Kubernetes cluster using Azure’s Standard D1 v2 Virtual Machines. According to Microsoft, ‘D series VMs are general purpose VM sizes provide balanced CPU-to-memory ratio. They are ideal for testing and development, small to medium databases, and low to medium traffic web servers.’ Azure D1 v2 VM’s are based on Linux OS images, currently Debian 8 (Jessie), with 1 vCPU and 3.5 GB of memory. By default with AKS, each VM receives 30 GiB of Standard HDD attached storage.

AKS_002_CreateCluster
You should always select the type and quantity of the cluster’s VMs and their attached storage, optimized for estimated traffic volumes and the specific workloads you are running. This can be done using the --node-count--node-vm-size, and --node-osdisk-size arguments with the az aks create command.

Deployment

The Voter API resources are deployed to its own Kubernetes Namespace, voter-api. The NGINX Ingress Controller resources are deployed to a different namespace, ingress-nginx. Separate namespaces help organize individual Kubernetes resources and separate different concerns.

Voter API

First, the voter-api namespace is created. Then, five required Kubernetes Secrets are created within the namespace. These secrets all contain sensitive information, such as passwords, that should not be shared. There is one secret for each of the three Cosmos DB database connection strings, one secret for the Azure Service Bus connection string, and one secret for the Let’s Encrypt SSL/TLS certificate and private key, used for secure HTTPS access to the Voter API.

AKS_004_CreateVoterAPI

Secrets

The Voter API’s secrets are used to populate environment variables within the pod’s containers. The environment variables are then available for use within the containers. Below is a snippet of the Voter pods resource file showing how the Cosmos DB and Service Bus connection strings secrets are used to populate environment variables.

env:
  - name: AZURE_SERVICE_BUS_CONNECTION_STRING
    valueFrom:
      secretKeyRef:
        name: azure-service-bus
        key: connection-string
  - name: SPRING_DATA_MONGODB_URI
    valueFrom:
      secretKeyRef:
        name: azure-cosmosdb-voter
        key: connection-string

Shown below, the Cosmos DB and Service Bus connection strings secrets have been injected into the Voter container and made available as environment variables to the microservice’s executable JAR file on start-up. As environment variables, the secrets are visible in plain text. Access to containers should be tightly controlled through Kubernetes RBAC and Azure AD, to ensure sensitive information, such as secrets, remain confidential.

AKS_014_EnvVars

Next, the three Kubernetes ReplicaSet resources, corresponding to the three Spring microservices, are created using Deployment controllers. According to Kubernetes, a Deployment that configures a ReplicaSet is now the recommended way to set up replication. The Deployments specify three replicas of each of the three Spring Services, resulting in a total of nine Kubernetes Pods.

Each pod, by default, will be scheduled on a different node if possible. According to Kubernetes, ‘the scheduler will automatically do a reasonable placement (e.g. spread your pods across nodes, not place the pod on a node with insufficient free resources, etc.).’ Note below how each of the three microservice’s three replicas has been scheduled on a different node in the three-node AKS cluster.

AKS_005B_CreateVoterPods

Next, the three corresponding Kubernetes ClusterIP-type Services are created. And lastly, the Kubernetes Ingress is created. According to Kubernetes, the Ingress resource is an API object that manages external access to the services in a cluster, typically HTTP. Ingress provides load balancing, SSL termination, and name-based virtual hosting.

The Ingress configuration contains the routing rules used with the NGINX Ingress Controller. Shown below are the routing rules for each of the three microservices within the Voter API. Incoming API requests are routed to the appropriate pod and service port by NGINX.

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: voter-ingress
  namespace: voter-api
  annotations:
    ingress.kubernetes.io/ssl-redirect: "true"
spec:
  tls:
  - hosts:
    - api.voter-demo.com
    secretName: api-voter-demo-secret
  rules:
  - http:
      paths:
      - path: /candidate
        backend:
          serviceName: candidate
          servicePort: 8080
      - path: /election
        backend:
          serviceName: election
          servicePort: 8080
      - path: /voter
        backend:
          serviceName: voter
          servicePort: 8080

The screengrab below shows all of the Voter API resources created on AKS.

AKS_005B_CreateVoterAPI

NGINX Ingress Controller

After completing the deployment of the Voter API, the NGINX Ingress Controller is created. It starts with creating the ingress-nginx namespace. Next, the NGINX Ingress Controller is created, consisting of the NGINX Ingress Controller, three Kubernetes ConfigMap resources, and a default back-end application. The Controller and backend each have their own Service resources. Like the Voter API, each has three replicas, for a total of six pods. Together, the Ingress resource and NGINX Ingress Controller manage traffic to the Spring microservices.

The screengrab below shows all of the NGINX Ingress Controller resources created on AKS.

AKS_015_NGINX_Resources.PNG

The  NGINX Ingress Controller Service, shown above, has an external public IP address associated with itself.  This is because that Service is of the type, Load Balancer. External requests to the Voter API will be routed through the NGINX Ingress Controller, on this IP address.

kind: Service
apiVersion: v1
metadata:
  name: ingress-nginx
  namespace: ingress-nginx
  labels:
    app: ingress-nginx
spec:
  externalTrafficPolicy: Local
  type: LoadBalancer
  selector:
    app: ingress-nginx
  ports:
  - name: http
    port: 80
    targetPort: http
  - name: https
    port: 443
    targetPort: https

If you are only using HTTPS, not HTTP, then the references to HTTP and port 80 in the Ingress configuration are unnecessary. The NGINX Ingress Controller’s resources are explained in detail in the GitHub documentation, along with further configuration instructions.

DNS

To provide convenient access to the Voter API and the Voter Client, my domain, voter-demo.com, is associated with the public IP address associated with the Voter API Ingress Controller and with the public IP address associated with the Voter Client Azure Web App. DNS configuration is done through Azure’s DNS Zone resource.

AKS_008_FinalDNS

The two TXT type records might not look as familiar as the SOA, NS, and A type records. The TXT records are required to associate the domain entries with the Voter Client Azure Web App. Browsing to http://www.voter-demo.com or simply http://voter-demo.com brings up the Voter Client.

VoterClientAngular5_small.png

The Client sends and receives data via the Voter API, available securely at https://api.voter-demo.com.

Routing API Requests

With the Pods, Services, Ingress, and NGINX Ingress Controller created and configured, as well as the Azure Layer 4 Load Balancer and DNS Zone, HTTP requests from API consumers are properly and securely routed to the appropriate microservices. In the example below, three back-to-back requests are made to the voter/info API endpoint. HTTP requests are properly routed to one of the three Voter pod replicas using the default round-robin algorithm, as proven by the observing the different hostnames (pod names) and the IP addresses (private pod IPs) in each HTTP response.

AKS_013B_LoadBalancingReplicaSets.PNG

Final Architecture

Shown below is the final Voter API Azure architecture. To simplify the diagram, I have deliberately left out the three microservice’s ClusterIP-type Services, the three default back-end application pods, and the default back-end application’s ClusterIP-type Service. All resources shown below are within the single East US Azure region, except DNS, which is a global resource.

kub-aks-v10-small.png

Shown below is the new Azure Resource Group created by Azure during the AKS provisioning process. The Resource Group contains the various resources required to support the AKS cluster, NGINX Ingress Controller, and the Voter API. Necessary Azure resources were automatically provisioned when I provisioned AKS and when I created the new Voter API and NGINX resources.

AKS_006_FinalRG

In addition to the Resource Group above, the original Resource Group contains the AKS Container Service resource itself, Service Bus, Cosmos DB, and the DNS Zone resource.

AKS_007_FinalRG

The Voter Client Web App, consisting of the Azure App Service and App Service plan resource, is located in a third, separate Resource Group, not shown here.

Cleaning Up AKS

A nice feature of AKS, running a az aks delete command will delete all the Azure resources created as part of provisioning AKS, the API, and the Ingress Controller. You will have to delete the Cosmos DB, Service Bus, and DNS Zone resources, separately.

az aks delete \
  --name cluser_name_goes_here \
  --resource-group resource_group_name_goes_here

Conclusion

Taking advantage of Kubernetes with AKS, and the array of Azure’s enterprise-grade resources, the Voter API was shifted from a simple Docker architecture to a production-ready solution. The Voter API is now easier to manage, horizontally scalable, fault-tolerant, and marginally more secure. It is capable of reliably supporting dozens more microservices, with multiple replicas. The Voter API will handle a high volume of data transactions and event messages.

There is much more that needs to be done to productionalize the Voter API on AKS, including:

  • Add multi-region failover of Cosmos DB
  • Upgrade to Service Bus Standard or Premium Tier
  • Optimized Azure VMs and storage for anticipated traffic volumes and application-specific workloads
  • Implement Kubernetes RBAC
  • Add Monitoring, logging, and alerting with Envoy or similar
  • Secure end-to-end TLS communications with Itsio or similar
  • Secure the API with OAuth and Azure AD
  • Automate everything with DevOps – AKS provisioning, testing code, creating resources, updating microservices, and managing data

All opinions in this post are my own, and not necessarily the views of my current or past employers or their clients.

, , , , , , , , , , , , , ,

Leave a comment

First Impressions of AKS, Azure’s New Managed Kubernetes Container Service

Kubernetes as a Service

On October 24, 2017, less than a month prior to writing this post, Microsoft released the public preview of Managed Kubernetes for Azure Container Service (AKS). According to Microsoft, the goal of AKS is to simplify the deployment, management, and operations of Kubernetes. According to PM Lead, Containers @ Microsoft Azure, in a blog post, AKS ‘features an Azure-hosted control plane, automated upgrades, self-healing, easy scaling.’ Monroy goes on to say, ‘with AKS, customers get the benefit of open source Kubernetes without complexity and operational overhead.

Unquestionably, Kubernetes has become the leading Container-as-a-Service (CaaS) choice, at least for now. Along with the release of AKS by Microsoft, there have been other recent announcements, which reinforce Kubernetes dominance. In late September, Rancher Labs announced the release of Rancher 2.0. According to Rancher, Rancher 2.0 would be based on Kubernetes. In mid-October, at DockerCon Europe 2017, Docker announced they were integrating Kubernetes into the Docker platform. Even AWS seems to be warming up to Kubernetes, despite their own ECS, according to sources. There are rumors AWS will announce a Kubernetes offering at AWS re:Invent 2017, starting a week from now.

Previewing AKS

Being a big fan of both Azure and Kubernetes, I decided to give AKS a try. I chose to deploy an existing, simple, multi-tier web application, which I had used in several previous posts, including Eventual Consistency: Decoupling Microservices with Spring AMQP and RabbitMQ. All the code used for this post is available on GitHub.

Sample Application

The application, the Voter application, is composed of an AngularJS frontend client-side UI, and two Java Spring Boot microservices, both backed by individual MongoDB databases, and fronted with an HAProxy-based API Gateway. The AngularJS UI calls the API Gateway, which in turn calls the Spring services. The two microservices communicate with each other using HTTP-based inter-process communication (IPC). Although I would prefer event-based service-to-service IPC, HTTP-based IPC was simpler to implement, for this post.

AKS v4

Interestingly, the Voter application was designed using Docker Community Edition for Mac and deployed to AWS using Docker Community Edition for AWS. Not only would this be my chance to preview AKS, but also an opportunity to compare the ease of developing for Docker CE on AWS using a Mac, to developing for Kubernetes with AKS using Docker Community Edition for Windows.

Required Software

In order to develop for AKS on my Windows 10 Enterprise workstation, I first made sure I had the latest copies of the following software:

If you are following along with the post, make sure you have the latest version of the Azure CLI, minimally 2.0.21, according to the Azure CLI release notes. Also, I happen to be running the latest version of Docker CE from the Edge Channel. However, either channel’s latest release of Docker CE for Windows should work for this post. Using PowerShell is optional. I prefer PowerShell over working from the Windows Command Prompt, if for nothing else than to preserve my command history, by default.

AKS_V2_04

Kubernetes Resources with Kompose

Originally developed for Docker CE, the Voter application stack was defined in a single Docker Compose file.

To work on AKS, the application stack’s configuration needs to be reproduced as Kubernetes configuration files. Instead of writing the configuration files manually, I chose to use kompose. Kompose is described on its website as ‘a conversion tool for Docker Compose to container orchestrators such as Kubernetes.’ Using kompose, I was able to automatically convert the Docker Compose file into analogous Kubernetes resource configuration files.

kompose convert -f docker-compose.yml

Each Docker service in the Docker Compose file was translated into a separate Kubernetes Deployment resource configuration file, as well as a corresponding Service resource configuration file.

AKS_Demo_08

For the AngularJS Client Service and the HAProxy API Gateway Service, I had to modify the Service configuration files to switch the Service type to a Load Balancer (type: LoadBalancer). Being a Load Balancer, Kubernetes will assign a publically accessible IP address to each Service; the reasons for which are explained later in the post.

The MongoDB service requires a persistent storage volume. To accomplish this with Kubernetes, kompose created a PersistentVolumeClaims resource configuration file. I did have to create a corresponding PersistentVolume resource configuration file. It was also necessary to modify the PersistentVolumeClaims resource configuration file, specifying the Storage Class Name as manual, to correspond to the AKS Storage Class configuration (storageClassName: manual).

From the original Docker Compose file, containing five Docker services, I ended up with a dozen individual Kubernetes resource configuration files. Individual configuration files are optimal for fine-grain management of Kubernetes resources. The Docker Compose file and the Kubernetes resource configuration files are included in the GitHub project.

git clone \
  --branch master --single-branch --depth 1 --no-tags \
  https://github.com/garystafford/azure-aks-demo.git

Creating AKS Resources

New AKS Feature Flag

According to Microsoft, to start with AKS, while still a preview, creating new clusters requires a feature flag on your subscription.

az provider register -n Microsoft.ContainerService

Using a brand new Azure account for this demo, I also needed to activate two additional feature flags.

az provider register -n Microsoft.Network
az provider register -n Microsoft.Compute

If you are missing required features flags, you will see errors, similar to. the below error.

Operation failed with status: ’Bad Request’. Details: Required resource provider registrations Microsoft.Compute,Microsoft.Network are missing.

Resource Group

AKS requires an Azure Resource Group for AKS. I chose to create a new Resource Group, using the Azure CLI.

az group create \
  --resource-group resource_group_name_goes_here \
  --location eastus

AKS_Demo_01

New Kubernetes Cluster

Using the aks feature of the Azure CLI version 2.0.21 or later, I provisioned a new Kubernetes cluster. By default, Azure will create a 3-node cluster. You can override the default number of nodes using the --node-count parameter; I chose one node. The version of Kubernetes you choose is also configurable using the --kubernetes-version parameter. I selected the latest Kubernetes version available with AKS, 1.8.2.

az aks create \
  --name cluser_name_goes_here \
  --resource-group resource_group_name_goes_here \
  --node-count 1 \
  --generate-ssh-keys \
  --kubernetes-version 1.8.2

AKS_Demo_03

The newly created Azure Resource Group and AKS Kubernetes Cluster were both then visible on the Azure Portal.

AKS_Demo_04b

In addition to the new Resource Group I created, Azure also created a second Resource Group containing seven Azure resources. These Azure resources include a Virtual Machine (the single Kubernetes node), Network Security Group, Network Interface, Virtual Network, Route Table, Disk, and an Availability Group.

AKS_Demo_05b

With AKS up and running, I used another Azure CLI command to create a proxy connection to the Kubernetes Dashboard, which was deployed automatically and was running within the new AKS Cluster. The Kubernetes Dashboard is a general purpose, web-based UI for Kubernetes clusters.

az aks browse \
  --name cluser_name_goes_here \
  --resource-group resource_group_name_goes_here

AKS_Demo_23

Although no applications were deployed to AKS, yet, there were several Kubernetes components running within the AKS Cluster. Kubernetes components running within the kube-system Namespace, included heapster, kube-dns, kubernetes-dashboard, kube-proxy, kube-svc-redirect, and tunnelfront.

AKS_Demo_06B

Deploying the Application

MongoDB should be deployed first. Both the Voter and Candidate microservices depend on MongoDB. MongoDB is composed of four Kubernetes resources, a Deployment resource, Service resource, PersistentVolumeClaim resource, and PersistentVolume resource. I used kubectl, the command line interface for running commands against Kubernetes clusters, to create the four MongoDB resources, from the configuration files.

kubectl create \
  -f voter-data-vol-persistentvolume.yaml \
  -f voter-data-vol-persistentvolumeclaim.yaml \
  -f mongodb-deployment.yaml \
  -f mongodb-service.yaml

AKS_Demo_09

After MongoDB was deployed and running, I created the four remaining Deployment resources, Client, Gateway, Voter, and Candidate, from the Deployment resource configuration files. According to Kubernetes, ‘a Deployment controller provides declarative updates for Pods and ReplicaSets. You describe a desired state in a Deployment object, and the Deployment controller changes the actual state to the desired state at a controlled rate.

AKS_Demo_10

Lastly, I created the remaining Service resources from the Service resource configuration files. According to Kubernetes, ‘a Service is an abstraction which defines a logical set of Pods and a policy by which to access them.

AKS_Demo_11

Switching back to the Kubernetes Dashboard, the Voter application components were now visible.

AKS_Demo_13

There were five Kubernetes Pods, one for each application component. Since there is only one Node in the Kubernetes Cluster, all five Pods were deployed to the same Node. There were also five corresponding Kubernetes Deployments.

AKS_Demo_14

Similarly, there were five corresponding Kubernetes ReplicaSets, the next-generation Replication Controller. There were also five corresponding Kubernetes Services. Note the Gateway and Client Services have an External Endpoint (External IP) associated with them. The IPs were created as a result of adding the Load Balancer Service type to their Service resource configuration files, mentioned earlier.

AKS_Demo_15.PNG

Lastly, note the Persistent Disk Claim for MongoDB, which had been successfully bound.

AKS_Demo_16

Switching back to the Azure Portal, following the application deployment, there were now three additional resources in the AKS Resource Group, a new Azure Load Balancer and two new Public IP Addresses. The Load Balancer is used to balance the Client and Gateway Services, which both have public IP addresses.

AKS_Demo_21b

To confirm the Gateway, Voter, and Candidate Services were reachable, using the public IP address of the Gateway Service, I browsed to HAProxy’s Statistics web page. Note the two backends, candidate and voter. The green color means HAProxy was able to successfully connect to both of these Services.

AKS_Demo_12

Accessing the Application

The Voter application’s AngularJS UI frontend can be accessed using the Client Service’s public IP address. However, this would not be very user-friendly. Even if I brought up the UI, using the public IP, the UI would be unable to connect to the HAProxy API Gateway, and subsequently, the Voter or Candidate Services. Based on the Client’s current configuration, the Client is expecting to find the Gateway at api.voter-demo.com:8080.

To make accessing the Client more user-friendly, and to ensure the Client has access to the Gateway, I provisioned an Azure DNS Zone resource for my domain, voter-demo.com. I assigned the DNS Zone to the AKS Resource Group.

AKS_Demo_20b

Within the new DNS Zone, I created three DNS records. The first record, an Alias (A) record, associated voter-demo.com with the public IP address of the Client Service. I added a second Alias (A) record for the www subdomain, also associating it with the public IP address of the Client Service. The third Alias (A) record associated the api subdomain with the public IP address of the Gateway Service.

AKS_Demo_18b

At a high level, the voter application’s routing architecture looks as follows. The client’s requests to the primary domain or to the api subdomain are resolved to one of the two public IP addresses configured in the load balancer’s frontend. The requests are passed to the load balancer’s backend pool, containing the single Azure VM, which is the single Kubernetes node, and onto the client or gateway Kubernetes Service. From there, requests are routed to one the appropriate Kubernetes Pods, containing the containerized application components, client or gateway.

kub-aks

Browsing to either http://voter-demo.com or http://www.voter-demo.com should bring up the Voter app UI (oh look, Hillary won this time…).

Mobile_App_View

Using Chrome’s Developer Tools, observe when a new vote is placed, an HTTP POST is made to the gateway, on the /voter/votes endpoint, http://api.voter-demo.com:8080/voter/votes. The Gateway then proxies this request to the Voter Service, at http://voter:8080/voter/votes. Since the Gateway and Voter Services both run within the same Cluster, the Gateway is able to use the Voter service’s name to address it, using Kubernetes kube-dns.

AKS_Demo_19b

Conclusion

In the past, I have developed, deployed, and managed containerized applications, using Rancher, AWS, AWS ECS, native Kubernetes, RedHat OpenShift, Docker Enterprise Edition, and Docker Community Edition. Based on my experience, and given my limited testing with Azure’s public preview of AKS, I am very impressed. Creating the Kubernetes Cluster could not have been easier. Scaling the Cluster, adding Persistent Volumes, and upgrading Kubernetes, is equally as easy. Conveniently, AKS integrates with other Kubernetes tools, like kubectl, kompose, and Helm.

I did run into some minor issues with the AKS Preview, such as being unable to connect to an earlier Cluster, after upgrading from the default Kubernetes version to 1.82. I also experience frequent disconnects when proxying to the Kubernetes Dashboard. I am sure the AKS Preview bugs will be worked out by the time AKS is officially released.

In addition to the many advantages of Kubernetes as a CaaS, a huge advantage of using AKS is the ability to easily integrate Azure’s many enterprise-grade compute, networking, database, caching, storage, and messaging resources. It would require minimal effort to swap out the Voter application’s single containerized version of MongoDB with a highly performant and available instance of Azure Cosmos DB. Similarly, it would be relatively easy to swap out the single containerized version of HAProxy with a fully-featured and secure instance of Azure API Management. The current version of the Voter application replies on RabbitMQ for service-to-service IPC versus this earlier application version’s reliance on HTTP-based IPC. It would be fairly simple to swap RabbitMQ for Azure Service Bus.

Lastly, AKS easily integrates with leading Development and DevOps tooling and processes. Building, managing, and deploying applications to AKS, is possible with Visual Studio, VSTS, Jenkins, Terraform, and Chef, according to Microsoft.

References

A few good references to get started with AKS:

All opinions in this post are my own, and not necessarily the views of my current or past employers or their clients.

, , , , , , , ,

1 Comment

Developing Applications for the Cloud with Azure App Services and MongoDB Atlas

Shift Left Cloud

The continued growth of compute services by leading Cloud Service Providers (CSPs) like Microsoft, Amazon, and Google are transforming the architecture of modern software applications, as well as the software development lifecycle (SDLC). Self-service access to fully-managed, reasonably-priced, secure compute has significantly increased developer productivity. At the same time, cloud-based access to cutting-edge technologies, like Artificial Intelligence (AI), Internet Of Things (IoT), Machine Learning, and Data Analytics, has accelerated the capabilities of modern applications. Finally, as CSPs become increasingly platform agnostic, Developers are no longer limited to a single technology stack or operating system. Today, Developers are solving complex problems with multi-cloud, multi-OS polyglot solutions.

Developers now leverage the Cloud from the very start of the software development process; shift left Cloud, if you will*. Developers are no longer limited to building and testing software on local workstations or on-premise servers, then throwing it over the wall to Operations for deployment to the Cloud. Developers using Azure, AWS, and GCP, develop, build, test, and deploy their code directly to the Cloud. Existing organizations are rapidly moving development environments from on-premise to the Cloud. New organizations are born in the Cloud, without the burden of legacy on-premise data-centers and servers under desks to manage.

Example Application

To demonstrate the ease of developing a modern application for the Cloud, let’s explore a simple API-based, NoSQL-backed web application. The application, The .NET Diner, simulates a rudimentary restaurant menu ordering interface. It consists of a single-page application (SPA) and two microservices backed by MongoDB. For simplicity, there is no API Gateway between the UI and the two services, as normally would be in place. An earlier version of this application was used in two previous posts, including Cloud-based Continuous Integration and Deployment for .NET Development.

The original restaurant order application was written with JQuery and RESTful .NET WCF Services. The new application, used in this post, has been completely re-written and modernized. The web-based user interface (UI) is written with Google’s Angular 4 framework using TypeScript. The UI relies on a microservices-based API, built with C# using Microsoft’s Web API 2 and .NET 4.7. The services rely on MongoDB for data persistence.

RestaurantDemoAPI

All code for this project is available on GitHub within two projects, one for the Angular UI and another for the C# services. The entire application can easily be built and run locally on Windows using MongoDB Community Edition. Alternately, to run the application in the Cloud, you will require an Azure and MongoDB Atlas account.

This post is primarily about the development experience. For brevity, the post will not delve into security, DevOps practices for CI/CD, and the complexities of staging and releasing code to Production.

Cross-Platform Development

The API, consisting of a set of C# microservices, was developed with Microsoft Visual Studio Community 2017 on Windows 10. Visual Studio touts itself as a full-featured Integrated Development Environment (IDE) for Android, iOS, Windows, web, and cloud. Visual Studio is easily integrated with Azure, AWS, and Google, through the use of Extensions. Visual Studio is an ideal IDE for cloud-centric application development.

Capture_VS2017_1

To simulate a typical mixed-platform development environment, the Angular UI front-end was developed with JetBrains WebStorm 2017 on Mac OS X. WebStorm touts itself as a powerful IDE for modern JavaScript development.

Webstorm

Other tools used to develop the application include Git and GitHub for source code, MongoDB Community Edition for local database development, and Postman for API development and testing, both locally and on Azure. All the development tools used in the post are cross-platform. Versions of WebStorm, Visual Studio, MongoDB, Postman, Git, Node.js, npm, and Bash are all available for Mac, Windows, and Linux. Cross-platform flexibility is key when developing modern multi-OS polyglot applications.

Postman

Postman was used to build, test, and document the application’s API. Postman is an excellent choice for developing RESTful APIs. With Postman, you define Collections of HTTP requests for each of your APIs. You then define Environments, such as Development, Test, and Production, against which you will execute the Collections of HTTP requests. Each environment consists of environment-specific variables. Those variables can be used to define API URLs and as request parameters.

Not only can you define static variables, Postman’s runtime, built on Node.js, is scriptable using JavaScript, allowing you to programmatically set dynamic variables, based on the results of HTTP requests and responses, as demonstrated below.

Postman2

Postman also allows you to write and run automated API integration tests, as well as perform load testing, as shown below.

Postman3

Azure App Services

The Angular browser-based UI and the C# microservices will be deployed to Azure using the Azure App Service. Azure App Service is nearly identical to AWS Elastic BeanStalk and Google App Engine.  According to Microsoft, Azure App Service allows Developers to quickly build, deploy, and scale enterprise-grade web, mobile, and API apps, running on Windows or Linux, using .NET, .NET Core, Java, Ruby, Node.js, PHP, and Python.

App Service is a fully-managed, turn-key platform. Azure takes care of infrastructure maintenance and load balancing. App Service easily integrates with other Azure services, such as API Management, Queue Storage, Azure Active Directory (AD), Cosmos DB, and Application Insights. Microsoft suggests evaluating the following four criteria when considering Azure App Services:

  • You want to deploy a web application that’s accessible through the Internet.
  • You want to automatically scale your web application according to demand without needing to redeploy.
  • You don’t want to maintain server infrastructure (including software updates).
  • You don’t need any machine-level customizations on the servers that host your web application.

There are currently four types of Azure App Services, which are Web Apps, Web Apps for Containers, Mobile Apps, and API Apps. The application in this post will use the Azure Web Apps for the Angular browser-based UI and Azure API Apps for the C# microservices.

MongoDB Atlas

Each of the C# microservices has separate MongoDB database. In the Cloud, the services use MongoDB Atlas, a secure, highly-available, and scalable cloud-hosted MongoDB service. Cloud-based databases, like Atlas, are often referred to as Database as a Service (DBaaS). Atlas is a Cloud-based alternative to traditional on-premise databases, as well as equivalent CSP-based solutions, such as Amazon DynamoDB, GCP Cloud Bigtable, and Azure Cosmos DB.

Atlas is an example of a SaaS who offer a single service or small set of closely related services, as an alternative to the big CSP’s equivalent services. Similar providers in this category include CloudAMQP (RabbitMQ as a Service), ClearDB (MySQL DBaaS), Akamai (Content Delivery Network), and Oracle Database Cloud Service (Oracle Database, RAC, and Exadata as a Service). Many of these providers, such as Atlas, are themselves hosted on AWS or other CSPs.

There are three pricing levels for MongoDB Atlas: Free, Essential, and Professional. To follow along with this post, the Free level is sufficient. According to MongoDB, with the Free account level, you get 512 MB of storage with shared RAM, a highly-available 3-node replica set, end-to-end encryption, secure authentication, fully managed upgrades, monitoring and alerts, and a management API. Atlas provides the ability to upgrade your account and CSP specifics at any time.

Once you register for an Atlas account, you will be able to log into Atlas, set up your users, whitelist your IP addresses for security, and obtain necessary connection information. You will need this connection information in the next section to configure the Azure API Apps.

Altas01

With the Free Atlas tier, you can view detailed Metrics about database cluster activity. However, with the free tier, you do not get access to Real-Time data insights or the ability to use the Data Explorer to view your data through the Atlas UI.

Altas03

Azure API Apps

The example application’s API consists of two RESTful microservices built with C#, the RestaurantMenu service and RestaurantOrder service. Both services are deployed as Azure API Apps. API Apps is a fully-managed platform. Azure performs OS patching, capacity provisioning, server management, and load balancing.

Microsoft Visual Studio has done an excellent job providing Extensions to make cloud integration a breeze. I will be using Visual Studio Tools for Azure in this post. Similar to how you create a Publish Profile for deploying applications to Internet Information Services (IIS), you create a Publish Profile for Azure App Services. Using the step-by-step user interface, you create a Microsft Azure App Service Web Deploy Publish Profile for each service. To create a new Profile, choose the Microsoft Azure App Service Target.

Capture_VS_Profile_1

You must be connected to your Azure account to create the Publish Profile. Give the service an App Name, choose your Subscription, and select or create a Resource Group and an App Service Plan.

Capture21

The App Service Plan defines the Location and Size for your API App container; these will determine the cost of the compute. I suggest putting the two API Apps and the Web App in the same location, in this case, East US.

Capture20

The Publish Profile is now available for deploying the services to Azure. No command line interaction is required. The services can be built and published to Azure with a single click from within Visual Studio.

Capture23

Configuration Management

Azure App Services is highly configurable. For example, each API App requires a different configuration, in each environment, to connect to different instances of MongoDB Atlas databases. For security, sensitive Atlas credentials are not stored in the source code. The Atlas URL and sensitive credentials are stored in App Settings on Azure. For this post, the settings were input directly into the Azure UI, as shown below. You will need to input your own Atlas URL and credentials.

The compiled C# services expect certain environment variables to be present at runtime to connect to MongoDB Atlas. These are provided through Azure’s App Settings. Access to the App Settings in Azure should be tightly controlled through Azure AD and fine-grained Azure Role-Based Access Control (RBAC) service.

Capture70

CORS

If you want to deploy the application from this post to Azure, there is one code change you will need to make to each service, which deals with Cross-Origin Resource Sharing (CORS). The services are currently configured to only accept traffic from my temporary Angular UI App Service’s URL. You will need to adjust the CORS configuration in the \App_Start\WebApiConfig.cs file in each service, to match your own App Service’s new URL.

CaptureCORS

Angular UI Web App

The Angular UI application will be deployed as an Azure Web App, one of four types of Azure App Services, mentioned previously. According to Microsoft, Web Apps allow Developers to program in their favorite languages, including .NET, Java, Node.js, PHP, and Python on Windows or .NET Core, Node.js, PHP or Ruby on Linux. Web Apps is a fully-managed platform. Azure performs OS patching, capacity provisioning, server management, and load balancing.

Using the Azure Portal, setting up a new Web App for the Angular UI is simple.

Capture31

Provide an App Name, Subscription, Resource Group, OS Type, and select whether or not you want Application Insights enabled for the Web App.

Capture33

Although an amazing IDE for web development, WebStorm lacks some of the direct integrations with Azure, AWS, and Google, available with other IDE’s, like Visual Studio. Since the Angular application was developed in WebStorm on Mac, we will take advantage of Azure App Service’s Continuous Deployment feature.

Azure Web Apps can be deployed automatically from most common source code management platforms, including Visual Studio Team Services (VSTS), GitHub, Bitbucket, OneDrive, and local Git repositories.

Capture34

For this post, I chose GitHub. To configure deployment from GitHub, select the GitHub Account, Organization, Project, and Branch from which Azure will deploy the Angular Web App.

Capture35

Configuring GitHub in the Azure Portal, Azure becomes an Authorized OAuth App on the GitHub account. Azure creates a Webhook, which fires each time files are pushed (git push) to the dist branch of the GitHub project’s repository.

Capture_GitHub_WebHooks

Using the ng build --dev --env=prod command, the Angular UI application must be first transpiled from TypeScript to JavaScript and bundled for deployment. The ng build command can be run from within WebStorm or from the command line.

Capture_NG_Build

The the --env=prod flag ensures that the Production environment configuration, containing the correct Azure API endpoints, issued transpiled into the build. This configuration is stored in the \src\environments\environment.prod.ts file, shown below. You will need to update these two endpoints to your own endpoints from the two API Apps you previously deployed to Azure.

Capture_Environment_Endpoints.PNG

Optionally, the code should be optimized for Production, by replacing the --dev flag with the --prod flag. Amongst other optimizations, the Production version of the code is uglified using UglifyJS. Note the difference in the build files shown below for Production, as compared to files above for Development.

Capture_NG_Build2

Since I chose GitHub for deployment to Azure, I used Git to manually push the local build files to the dist branch on GitHub.

Capture_GitHub_WebHooks2

Every time the webhook fires, Azure pulls and deploys the new build, overwriting the previously deployed version, as shown below.

Capture_Azure_CD

To stage new code and not immediately overwrite running code, Azure has a feature called Deployment slots. According to Microsoft, Deployment slots allow Developers to deploy different versions of Web Apps to different URLs. You can test a certain version and then swap content and configuration between slots. This is likely how you would eventually deploy your code to Production.

Up and Running

Below, the three Azure App Services are shown in the Azure Portal, successfully deployed and running. Note their Status, App Type, Location, and Subscription.

Capture60

Before exploring the deployed UI, the two Azure API Apps should be tested using Postman. Once the API is confirmed to be working properly, populated by making an HTTP Post request to the menuitems API, the RestaurantOrderService Azure API Service. When the HTTP Post request is made, the RestaurantOrderService stores a set of menu items in the RestaurantMenu Atlas MongoDB database, in the menus collection.

Capture_PopulateMenu

The Angular UI, the RestaurantWeb Azure Web App, is viewed by using the URL provided in the Web App’s Overview tab. The menu items displayed in the drop-down are supplied by an HTTP GET request to the menuitems API, provided by the RestaurantMenuService Azure API Service.

Capture_Final_UI_1

Your order is placed through an HTTP Post request to the orders API, the RestaurantOrderService Azure API Service. The RestaurantOrderService stores the order in the RestaurantOrder Atlas MongoDB database, in the orders collection. The order details are returned in the response body and displayed in the UI.

Capture_Final_UI_2

Once you have the development version of the application successfully up and running on Atlas and Azure, you can start to configure, test, and deploy additional application versions, as App Services, into higher Azure environments, such as Test, Performance, and eventually, Production.

Monitoring

Azure provides in-depth monitoring and performance analytics capabilities for your deployed applications with services like Application Insights. With Azure’s monitoring resources, you can monitor the live performance of your application and set up alerts for application errors and performance issues. Real-time monitoring useful when conducting performance tests. Developers can analyze response time of each API method and optimize the application, Azure configuration, and MongoDB databases, before deploying to Production.

Capture_Insights

Conclusion

This post demonstrated how the Cloud has shifted application development to a Cloud-first model. Future posts will demonstrate how an application, such as the app featured in this post, is secured, and how it is continuously built, tested, and deployed, using DevOps practices.

All opinions in this post are my own, and not necessarily the views of my current or past employers or their clients.

, , , , , , , , ,

Leave a comment

Cloud-based Continuous Integration and Deployment for .NET Development

Create a cloud-based, continuous integration and deployment toolchain for distributed .NET development teams, using GitHub, AppVeyor, and Microsoft Azure.

Introduction

Whether you are part of a large enterprise development environment, or a member of a small start-up, you are likely working with remote team members. You may be remote, yourself. Developers, testers, web designers, and other team members, commonly work remotely on software projects. Distributed teams, comprised of full-time staff, contractors, and third-party vendors, often work in different buildings, different cities, and even different countries.

If software is no longer strictly developed in-house, why should our software development and integration tools be located in-house? We live in a quickly evolving world of Saas, PaaS, and IaaS. Popular SaaS development tools include Visual Studio Online, GitHub, BitBucket, Travis-CI, AppVeyor, CloudBeesJIRA, AWS, Microsoft Azure, Nodejitsu, and Heroku, to name just a few. With all these ‘cord-cutting’ tools, there is no longer a need for distributed development teams to be tethered to on-premise tooling, via VPN tunnels and Remote Desktop Connections.

There are many combinations of hosted software development and integration tools available, depending on your technology stack, team size, and budget. In this post, we will explore one such toolchain for .NET development. Using GitGitHub, AppVeyor, and Microsoft Azure, we will continuously build, test, and deploy a multi-tier .NET solution, without ever leaving Visual Studio. This particular toolchain has strong integration between tools, and will scale to fit most development teams.

Git and GitHub
Git and GitHub are widely used in development today. Visual Studio 2013 has fully-integrated Git support and Visual Studio 2012 has supported Git via a plug-in since early last year. Git is fully compatible with Windows. Additionally, there are several third party tools available to manage Git and GitHub repositories on Windows. These include Git Bash (my favorite), Git GUI, and GitHub for Windows.

GitHub acts as a replacement for your in-house Git server. Developers commit code to their individual local Git project repositories. They then push, pull, and merge code to and from a hosted GitHub repository. For security, GitHub requires a registered username and password to push code. Data transfer between the local Git repository and GitHub is done using HTTPS with SSL certificates or SSH with public-key encryption. GitHub also offers two-factor authentication (2FA). Additionally, for those companies concerned about privacy and added security, GitHub offers private repositories. These plans range in price from $25 to $200 per month, currently.

GitHub View of Solution

GitHub View of Solution

AppVeyor
AppVeyor’s tagline is ‘Continuous Integration for busy developers’. AppVeyor automates building, testing and deployment of .NET applications. AppVeyor is similar to Jenkins and Hudson in terms of basic functionality, except AppVeyor is only provided as a SaaS. There are several hosted solutions in the continuous integration and delivery space similar to AppVeyor. They include CloudBees (hosted-Jenkins) and Travis-CI. While CloudBees and Travis CI works with several technology stacks, AppVeyor focuses specifically on .NET. Its closest competitor may be Microsoft’s new Visual Studio Online.

Identical to GitHub, AppVeyor also offers private repositories (spaces for building and testing code). Prices for private repositories currently range from $39 to $319 per month. Private repositories offer both added security and support.  AppVeyor integrates nicely with several cloud-based code repositories, including GitHub, BitBucket, Visual Studio Online, and Fog Creek’s Kiln.

AppVeyor View of Last Build of Solution

AppVeyor View of Latest Build of Solution

Azure
This post demonstrates continuous deployment from AppVeyor to a Microsoft Server 2012-based Azure VM. The VM has IIS 8.5, Web Deploy 3.5, IIS Web Management Service (WMSVC), and other components and configuration necessary to host the post’s sample Solution. AppVeyor would work just as well with Azure’s other hosting options, as well as other cloud-based hosting providers, such as AWS or Rackspace, which also supports the .NET stack.

New Microsoft Azure Portal View of VM

New Microsoft Azure Portal View of VM

Sample Solution

The Visual Studio Solution used for this post was originally developed as part of an earlier post, Consuming Cross-Domain WCF REST Services with jQuery using JSONP. The original Solution, from 2011, demonstrated jQuery’s AJAX capabilities to communicate with a RESTful WCF service, cross-domains, using JSONP. I have since updated and modernized the Solution for this post. The revised Solution is on a new branch (‘rev2014’) on GitHub. Major changes to the Solution include an upgrade from VS2010 to VS2013, the use of Git DVCS, NuGet package management, Web Publish Profiles, Web Essentials for bundling JS and CSS, Twitter Bootstrap, unit testing, and a lot of code refactoring.

Revised Restaurant Menu Demo Viewed on Android Tablet

Revised Restaurant Menu Demo Viewed on Android Tablet

The updated VS Solution contains the following four Projects:

  1. Restaurant – C# Class Library
  2. RestaurantUnitTests – Unit Test Project
  3. RestaurantWcfService – C# WCF Service Application
  4. RestaurantDemoSite – Web Site (JS/HTML5)
VS 2013 View of Solution

VS 2013 View of Solution

The Visual Studio Solution Explorer tab, here, shows all projects contained in the Solution, and the primary files and directories they contain.

As explained in the earlier post, the ‘RestaurantDemoSite’ web site makes calls to the ‘RestaurantWcfService’ WCF service. The WCF service exposes two operations, one that returns the menu (‘GetCurrentMenu’), and the other that accepts an order (‘SendOrder’). For simplicity, orders are stored in the files system as JSON files. No database is required for the Solution. All business logic is contained in the ‘Restaurant’ class library, which is referenced by the WCF service. This architecture is illustrated in this Visual Studio Assembly Dependencies Diagram.

Installing and Configuring the Solution

The README.md file in the GitHub repository contains instructions for installing and configuring this Solution. In addition, a set of PowerShell scripts, part of the Solution’s repository, makes the installation and configuration process, quick and easy. The scripts handle creating the necessary file directories and environment variables, setting file access permissions, and configuring IIS websites. Make sure to change the values of the environment variables before running the script. For reference, below are the contents of several of the supplied scripts. You should use the supplied scripts.

# Create environment variables
[Environment]::SetEnvironmentVariable("AZURE_VM_HOSTNAME", `
  "{YOUR HOSTNAME HERE}", "User")

[Environment]::SetEnvironmentVariable("AZURE_VM_USERNAME", `
  "{YOUR USERNME HERE}", "User")

[Environment]::SetEnvironmentVariable("AZURE_VM_PASSWORD", `
  "{YOUR PASSWORD HERE}", "User")

# Create new restaurant orders JSON file directory
$newDirectory = "c:\RestaurantOrders"

if (-not (Test-Path $newDirectory)){
  New-Item -Type directory -Path $newDirectory
}

$acl = Get-Acl $newDirectory
$ar = New-Object System.Security.AccessControl.FileSystemAccessRule(`
  "INTERACTIVE","Modify","ContainerInherit, ObjectInherit", "None", "Allow")
$acl.SetAccessRule($ar)
Set-Acl $newDirectory $acl

# Create new website directory
$newDirectory = "c:\RestaurantDemoSite"

if (-not (Test-Path $newDirectory)){
  New-Item -Type directory -Path $newDirectory
}

$acl = Get-Acl $newDirectory
$ar = New-Object System.Security.AccessControl.FileSystemAccessRule(`
  "IUSR","ReadAndExecute","ContainerInherit, ObjectInherit", "None", "Allow")
$acl.SetAccessRule($ar)
Set-Acl $newDirectory $acl

# Create new WCF service directory
$newDirectory = "c:\MenuWcfRestService"

if (-not (Test-Path $newDirectory)){
 New-Item -Type directory -Path $newDirectory
}

$acl = Get-Acl $newDirectory
$ar = New-Object System.Security.AccessControl.FileSystemAccessRule(`
 "IUSR","ReadAndExecute","ContainerInherit, ObjectInherit", "None", "Allow")
$acl.SetAccessRule($ar)

Set-Acl $newDirectory $acl
$ar = New-Object System.Security.AccessControl.FileSystemAccessRule(`
 "IIS_IUSRS","ReadAndExecute","ContainerInherit, ObjectInherit", "None", "Allow")
$acl.SetAccessRule($ar)
Set-Acl $newDirectory $acl

# Create main website in IIS
$newSite = "MenuWcfRestService"

if (-not (Test-Path IIS:\Sites\$newSite)){
  New-Website -Name $newSite -Port 9250 -PhysicalPath `
    c:\$newSite -ApplicationPool "DefaultAppPool"
}

# Create WCF service website in IIS
$newSite = "RestaurantDemoSite"

if (-not (Test-Path IIS:\Sites\$newSite)){
  New-Website -Name $newSite -Port 9255 -PhysicalPath `
    c:\$newSite -ApplicationPool "DefaultAppPool"
}

Cloud-Based Continuous Integration and Delivery

Webhooks
The first point of integration in our hosted toolchain is between GitHub and AppVeyor. In order for AppVeyor to work with GitHub, we use a Webhook. Webhooks are widely used to communicate events between systems, over HTTP. According to GitHub, ‘every GitHub repository has the option to communicate with a web server whenever the repository is pushed to. These webhooks can be used to update an external issue tracker, trigger CI builds, update a backup mirror, or even deploy to your production server.‘ Basically, we give GitHub permission to tell AppVeyor every time code is pushed to the GitHub. GitHub sends a HTTP POST to a specific URL, provided by AppVeyor. AppVeyor responds to the POST by cloning the GitHub repository, and building, testing, and deploying the Projects. Below is an example of a webhook for AppVeyor, in GitHub.

GitHub's AppVeyor Webhook Configuration

GitHub’s AppVeyor Webhook Configuration

Unit Tests
To help illustrate the use of AppVeyor for automated unit testing, the updated Solution contains a Unit Test Project. Every time code is committed to GitHub, AppVeyor will clone and build the Solution, followed by running the set of unit tests shown below. The project’s unit tests test the Restaurant class library (‘restaurant.dll’). The unit tests provide 100% code coverage, as shown in the Visual Studio Code Coverage Results tab, below:

Code Coverage Results for Restaurant Class Library

Code Coverage Results for Restaurant Class Library

AppVeyor runs the Solution’s automated unit tests using VSTest.Console.exe. VSTest.Console calls the unit test Project’s assembly (‘restaurantunittests.dll’).  As shown below, the VSTest command (in light blue) runs all tests, and then displays individual test results, a results summary, and the total test execution time.

AppVeyor Running Automated Unit Tests Using VSTest.Console

AppVeyor Running Automated Unit Tests Using VSTest.Console

VSTest.Console has several command line options similar to MSBuild. They can be adjusted to output various levels of feedback on test results. For larger projects, you can selectively choose which pre-defined test sets to run. Test sets needs are set-up in Solution, in advance.

Configuring Azure VM
Before we publish the Solution from AppVeyor to the Azure, we need to configure the VM. Again, we can use PowerShell to script most of the configuration. Most scripts are the same ones we used to configure our local environment. The README.md file in the GitHub repository contains instructions. The scripts handle creating the necessary file directories, setting file access permissions, configuring the IIS websites, creating the Web Deploy User account, and assigning it in IIS. For reference, below are the contents of several of the supplied scripts. You should use the supplied scripts.

# Create new restaurant orders JSON file directory
$newDirectory = "c:\RestaurantOrders"

if (-not (Test-Path $newDirectory)){
  New-Item -Type directory -Path $newDirectory
}

$acl = Get-Acl $newDirectory
$ar = New-Object System.Security.AccessControl.FileSystemAccessRule(`
  "INTERACTIVE","Modify","ContainerInherit, ObjectInherit", "None", "Allow")
$acl.SetAccessRule($ar)
Set-Acl $newDirectory $acl

# Create new website directory
$newDirectory = "c:\RestaurantDemoSite"

if (-not (Test-Path $newDirectory)){
  New-Item -Type directory -Path $newDirectory
}

$acl = Get-Acl $newDirectory
$ar = New-Object System.Security.AccessControl.FileSystemAccessRule(`
  "IUSR","ReadAndExecute","ContainerInherit, ObjectInherit", "None", "Allow")
$acl.SetAccessRule($ar)
Set-Acl $newDirectory $acl

# Create new WCF service directory
$newDirectory = "c:\MenuWcfRestService"

if (-not (Test-Path $newDirectory)){
 New-Item -Type directory -Path $newDirectory
}

$acl = Get-Acl $newDirectory
$ar = New-Object System.Security.AccessControl.FileSystemAccessRule(`
 "IUSR","ReadAndExecute","ContainerInherit, ObjectInherit", "None", "Allow")
$acl.SetAccessRule($ar)

Set-Acl $newDirectory $acl
$ar = New-Object System.Security.AccessControl.FileSystemAccessRule(`
 "IIS_IUSRS","ReadAndExecute","ContainerInherit, ObjectInherit", "None", "Allow")
$acl.SetAccessRule($ar)
Set-Acl $newDirectory $acl

# Create main website in IIS
$newSite = "MenuWcfRestService"

if (-not (Test-Path IIS:\Sites\$newSite)){
  New-Website -Name $newSite -Port 9250 -PhysicalPath `
    c:\$newSite -ApplicationPool "DefaultAppPool"
}

# Create WCF service website in IIS
$newSite = "RestaurantDemoSite"

if (-not (Test-Path IIS:\Sites\$newSite)){
  New-Website -Name $newSite -Port 9255 -PhysicalPath `
    c:\$newSite -ApplicationPool "DefaultAppPool"
}

# Create new local non-admin User and Group for Web Deploy

# Main variables (Change these!)
[string]$userName = "USER_NAME_HERE" # mjones
[string]$fullName = "FULL USER NAME HERE" # Mike Jones
[string]$password = "USER_PASSWORD_HERE" # pa$$w0RD!
[string]$groupName = "GROUP_NAME_HERE" # Development

# Create new local user account
[ADSI]$server = "WinNT://$Env:COMPUTERNAME"
$newUser = $server.Create("User", $userName)
$newUser.SetPassword($password)

$newUser.Put("FullName", "$fullName")
$newUser.Put("Description", "$fullName User Account")

# Assign flags to user
[int]$ADS_UF_PASSWD_CANT_CHANGE = 64
[int]$ADS_UF_DONT_EXPIRE_PASSWD = 65536
[int]$COMBINED_FLAG_VALUE = 65600

$flags = $newUser.UserFlags.value -bor $COMBINED_FLAG_VALUE
$newUser.put("userFlags", $flags)
$newUser.SetInfo()

# Create new local group
$newGroup=$server.Create("Group", $groupName)
$newGroup.Put("Description","$groupName Group")
$newGroup.SetInfo()

# Assign user to group
[string]$serverPath = $server.Path
$group = [ADSI]"$serverPath/$groupName, group"
$group.Add("$serverPath/$userName, user")

# Assign local non-admin User in IIS for Web Deploy
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.Web.Management")
[Microsoft.Web.Management.Server.ManagementAuthorization]::Grant(`
  $userName, "$Env:COMPUTERNAME\MenuWcfRestService", $FALSE)
[Microsoft.Web.Management.Server.ManagementAuthorization]::Grant(`
  $userName, "$Env:COMPUTERNAME\RestaurantDemoSite", $FALSE)

Publish Profiles
The second point of integration in our toolchain is between AppVeyor and the Azure VM. We will be using Microsoft’s Web Deploy to deploy our Solution from AppVeyor to Azure.  Web Deploy integrates with the IIS Web Management Service (WMSVC) for remote deployment by non-administrators. I have already configured Web Deploy and created a non-administrative user on the Azure VM. This user’s credentials will be used for deployments. These are the credentials in the username and password environment variables we created.

To continuously deploy to Azure, we will use Web Publish Profiles with Microsoft’s Web Deploy technology. Both the website and WCF service projects contain individual profiles for local development (‘LocalMachine’), as well as deployment to Azure (‘AzureVM’). The ‘AzureVM’ profiles contain all the configuration information AppVeyor needs to connect to the Azure VM and deploy the website and WCF service.

The easiest way to create a profile is by right-clicking on the project and selecting the ‘Publish…’ and ‘Publish Web Site’ menu items. Using the Publish Web wizard, you can quickly build and validate a profile.

Publish Web Profile Tab

Publish Web Profile Tab

Each profile in the above Profile drop-down, represents a ‘.pubxml’ file. The Publish Web wizard is merely a visual interface to many of the basic configurable options found in the Publish Profile’s ‘.pubxml’ file. The .pubxml profile files can be found in the Project Explorer. For the website, profiles are in the ‘App_Data’ directory (i.e. ‘Restaurant\RestaurantDemoSite\App_Data\PublishProfiles\AzureVM.pubxml’). For the WCF service, profiles are in the ‘Properties’ directory (i.e. ‘Restaurant\RestaurantWcfService\Properties\PublishProfiles\AzureVM.pubxml’).

As an example, below are the contents of the ‘LocalMachine’ profile for the WCF service (‘LocalMachine.pubxml’). This is about as simple as a profile gets. Note since we are deploying locally, the profile is configured to open the main page of the website in a browser, after deployment; a helpful time-saver during development.

<?xml version="1.0" encoding="utf-8"?>
<!--
This file is used by the publish/package process of your Web project.
You can customize the behavior of this process by editing this MSBuild file.
In order to learn more about this please visit http://go.microsoft.com/fwlink/?LinkID=208121.
-->
<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <PropertyGroup>
        <WebPublishMethod>FileSystem</WebPublishMethod>
        <LastUsedBuildConfiguration>Debug</LastUsedBuildConfiguration>
        <LastUsedPlatform>Any CPU</LastUsedPlatform>
        <SiteUrlToLaunchAfterPublish>http://localhost:9250/RestaurantService.svc/help</SiteUrlToLaunchAfterPublish>
        <LaunchSiteAfterPublish>True</LaunchSiteAfterPublish>
        <ExcludeApp_Data>True</ExcludeApp_Data>
        <publishUrl>C:\MenuWcfRestService</publishUrl>
        <DeleteExistingFiles>True</DeleteExistingFiles>
    </PropertyGroup>
</Project>

A key change we will make is to use environment variables in place of sensitive configuration values in the ‘AzureVM’ Publish Profiles. The Web Publish wizard does not allow this change. To do this, we must edit the ‘AzureVM.pubxml’ file for both the website and the WCF service. We will replace the hostname of the server where we will deploy the projects with a variable (i.e. AZURE_VM_HOSTNAME = ‘MyAzurePublicServer.net’). We will also replace the username and password used to access the deployment destination. This way, someone accessing the Solution’s source code, won’t be able to obtain any sensitive information, which would give them the ability to hack your site. Note the use of the ‘AZURE_VM_HOSTNAME’ and ‘AZURE_VM_USERNAME’ environment variables, show below.

<?xml version="1.0" encoding="utf-8"?>
<!--
This file is used by the publish/package process of your Web project.
You can customize the behavior of this process by editing this MSBuild file.
In order to learn more about this please visit http://go.microsoft.com/fwlink/?LinkID=208121.
-->
<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <PropertyGroup>
        <WebPublishMethod>MSDeploy</WebPublishMethod>
        <LastUsedBuildConfiguration>AppVeyor</LastUsedBuildConfiguration>
        <LastUsedPlatform>Any CPU</LastUsedPlatform>
        <SiteUrlToLaunchAfterPublish />
        <LaunchSiteAfterPublish>False</LaunchSiteAfterPublish>
        <ExcludeApp_Data>True</ExcludeApp_Data>
        <MSDeployServiceURL>https://$(AZURE_VM_HOSTNAME):8172/msdeploy.axd</MSDeployServiceURL>
        <DeployIisAppPath>MenuWcfRestService</DeployIisAppPath>
        <RemoteSitePhysicalPath />
        <SkipExtraFilesOnServer>False</SkipExtraFilesOnServer>
        <MSDeployPublishMethod>WMSVC</MSDeployPublishMethod>
        <EnableMSDeployBackup>True</EnableMSDeployBackup>
        <UserName>$(AZURE_VM_USERNAME)</UserName>
        <_SavePWD>False</_SavePWD>
        <_DestinationType>AzureVirtualMachine</_DestinationType>
    </PropertyGroup>
</Project>

The downside of adding environment variables to the ‘AzureVM’ profiles, the Publish Profile wizard feature within Visual Studio will no longer allow us to deploy, using the ‘AzureVM’ profiles. As demonstrated below, after substituting variables for actual values, the ‘Server’ and ‘User name’ values will no longer display properly. We can confirm this by trying to validate the connection, which fails. This does not indicate your environment variable values are incorrect, only that Visual Studio can longer correctly parse the ‘AzureVM.pubxml’ file and display it properly in the IDE. No big deal…

Publish Web Connection Tab - Failed Validation

Publish Web Connection Tab – Failed Validation

We can use the command line or PowerShell to deploy with the ‘AzureVM’ profiles.  AppVeyor accepts both command line input, as well as PowerShell for most tasks. All examples in this post and in the GitHub repository use PowerShell.

To build and deploy (publish) to Azure from the command line or PowerShell, we will use MSBuild. Below are the MSBuild commands used by AppVeyor to build our Solution, and then deploy our Solution to Azure. The first two MSBuild commands build the WCF service and the website. The second two deploy them to Azure. There are several ways you could construct these commands to successfully build and deploy this Solution. I found these commands to be the most succinct. I have split the build and the deploy functions so that the AppVeyor can run the automated unit tests, in between. If the tests don’t pass, we don’t want to deploy the code.

# Build WCF service
# (AppVeyor config ignores website Project in Solution)
msbuild Restaurant\Restaurant.sln `
 /p:Configuration=AppVeyor /verbosity:minimal /nologo

# Build website
msbuild Restaurant\RestaurantDemoSite\website.publishproj `
 /p:Configuration=Release /verbosity:minimal /nologo

Write-Host "*** Solution builds complete."
# Deploy WCF service
# (AppVeyor config ignores website Project in Solution)
msbuild Restaurant\Restaurant.sln `
 /p:DeployOnBuild=true /p:PublishProfile=AzureVM /p:Configuration=AppVeyor `
 /p:AllowUntrustedCertificate=true /p:Password=$env:AZURE_VM_PASSWORD `
 /verbosity:minimal /nologo

# Deploy website
msbuild Restaurant\RestaurantDemoSite\website.publishproj `
 /p:DeployOnBuild=true /p:PublishProfile=AzureVM /p:Configuration=Release `
 /p:AllowUntrustedCertificate=true /p:Password=$env:AZURE_VM_PASSWORD `
 /verbosity:minimal /nologo

Write-Host "*** Solution deployments complete."

Below is the output from AppVeyor showing the WCF Service and website’s deployment to Azure. Deployment is the last step in the continuous delivery process. At this point, the Solution was already built and the automated unit tests completed, successfully.

AppVeyor Output from Deployments to Azure.

AppVeyor Output from Deployments to Azure.

Below is the final view of the sample Solution’s WCF service and web site deployed to IIS 8.5 on the Azure VM.

Final View of IIS Sites Running on Azure VM

Final View of IIS Sites Running on Azure VM

Links

 

, , , , , , , , , , , , , , , , , ,

1 Comment