Posts Tagged Oracle Linux 5
Create a new WebLogic Server domain on Oracle’s Pre-built Development VM. Remotely deploy a sample web application to the domain from a remote machine.
In my last two posts, Using Oracle’s Pre-Built Enterprise Java VM for Development Testing and Resizing Oracle’s Pre-Built Development Virtual Machines, I introduced Oracle’s Pre-Built Enterprise Java Development VM, aka a ‘virtual appliance’. Oracle has provided ready-made VMs that would take a team of IT professionals days to assemble. The Oracle Linux 5 OS-based VM has almost everything that comprises basic enterprise test and production environment based on the Oracle/Java technology stack. The VM includes Java JDK 1.6+, WebLogic Server, Coherence, TopLink, Subversion, Hudson, Maven, NetBeans, Enterprise Pack for Eclipse, and so forth.
One of the first things you will probably want to do, once your Oracle’s Pre-Built Enterprise Java Development VM is up and running, is deploy an application to WebLogic Server. According to Oracle, WebLogic Server is ‘a scalable, enterprise-ready Java Platform, Enterprise Edition (Java EE) application server.’ Even if you haven’t used WebLogic Server before, don’t worry, Oracle has designed it to be easy to get started.
In this post I will cover creating a new WebLogic Server (WLS) domain, and the deployment a simple application to WLS from a remote development machine. The major steps in the process presented in this post are as follows:
- Create a new WLS domain
- Create and build a sample application
- Deploy the sample application to the new WLS domain
- Access deployed application via a web browser
First, let me review how I have my VM configured for networking, so you will understand my deployment methodology, discussed later. The way you configure your Oracle VM VirtualBox appliance will depend on your network topology. Again, keeping it simple for this post, I have given the Oracle VM a static IP address (192.168.1.88). The machine on which I am hosting VirtualBox uses DHCP to obtain an IP address on the same local wireless network.
For the VM’s VirtualBox networking mode, I have chosen the ‘Bridged Adapter‘ mode. Using this mode, any machine on the network can access the VM through the host machine, via the VM’s IP address. One of the best posts I have read on VM networking is on Oracle’s The Fat Bloke Sings blog, here.
Creating New WLS Domain
A domain, according Oracle, is ‘the basic administrative unit of WebLogic Server. It consists of one or more WebLogic Server instances, and logically related resources and services that are managed, collectively, as one unit.’ Although the Oracle Development VM comes with pre-existing domains, we will create our own for this post.
To create the new domain, we will use the Oracle’s Fusion Middleware Configuration Wizard. The Wizard will take you through a step-by-step process to configure your new domain. To start the wizard, from within the Oracle VM, open a terminal window, and use the following command to switch to the Wizard’s home directory and start the application.
There are a lot of configuration options available, using the Wizard. I have selected some basic settings, shown below, to configure the new domain. Feel free to change the settings as you step through the Wizard, to meet your own needs. Make sure to use the ‘Development Mode’ Start Mode Option for this post. Also, make sure to note the admin port of the domain, the domain’s location, and the username and password you choose.
Starting the Domain
To start the new domain, open a terminal window in the VM and run the following command to change to the root directory of the new domain and start the WLS domain instance. Your domain path and domain name may be different. The start script command will bring up a new terminal window, showing you the domain starting.
WLS Administration Console
Once the domain starts, test it by opening a web browser from the host machine and entering the URL of the WLS Administration Console. If your networking is set-up correctly, the host machine will able to connect to the VM and open the domain, running on the port you indicated when creating the domain, on the static IP address of the VM. If your IP address and port are different, make sure to change the URL. To log into WLS Administration Console, use the username and password you chose when you created the domain.
Before we start looking around the new domain however, let’s install an application into it.
Sample Java Application
If you have an existing application you want to install, you can skip this part. If you don’t, we will quickly create a simple Java EE Hello World web application, using a pre-existing sample project in NetBeans – no coding required. From your development machine, create a new Samples -> Web Services -> REST: Hello World (Java EE 6) Project. You now have a web project containing a simple RESTful web service, Servlet, and Java Server Page (.jsp). Build the project in NetBeans. We will upload the resulting .war file manually, in the next step.
In a previous post, Automated Deployment to GlassFish Using Jenkins CI Server and Apache Ant, we used the same sample web application to demonstrate automated deployments to Oracle’s GlassFish application server.
Deploying the Application
There are several methods to deploy applications to WLS, depending on your development workflow. For this post, we will keep it simple. We will manually deploy our web application’s .war file to WLS using the browser-based WLS Administration Console. In a future post, we will use Hudson, also included on the VM, to build and deploy an application, but for now we will do it ourselves.
To deploy the application, switch back to the WLS Administration Console. Following the screen grabs below, you will select the .war file, built from the above web application, and upload it to the Oracle VM’s new WLS domain. The .war file has all the necessary files, including the RESTful web service, Servlet, and the .jsp page. Make sure to deploy it as an ‘application’ as opposed to a ‘library’ (see ‘target style’ configuration screen, below).
Accessing the Application
Now that we have deployed the Hello World application, we will access it from our browser. From any machine on the same network, point a browser to the following URL. Adjust your URL if your VM’s IP address and domain’s port is different.
The Hello World RESTful web service’s Web Application Description Language (WADL) description can be viewed at:
Since the Oracle VM is accessible from anywhere on the network, the deployed application is also accessible from any device on the network, as demonstrated below.
This was a simple demonstration of deploying an application to WebLogic Server on Oracle’s Pre-Built Enterprise Java Development VM. WebLogic Server is a powerful, feature-rich Java application server. Once you understand how to configure and administer WLS, you can deploy more complex applications. In future posts we will show a more common, slightly more complex example of automated deployment from Hudson. In addition, we will show how to create a datasource in WLS and access it from the deployed application, to talk to a relational database.
Install and configure Oracle’s Pre-Built Enterprise Java Development VM, with Oracle Linux 5, to create quick, full-featured development test environments.
Virtual Machines for Software Developers
As software engineers, we spend a great deal of time configuring our development machines to simulate test and production environments in which our code will eventually run. With the Microsoft/.NET technology stack, that most often means installing and configuring .NET, IIS, and SQL Server. With the Oracle/Java technology stack – Java, WebLogic or GlassFish Application Server, and Oracle 11g.
Within the last few years, the growth of virtual machines (VMs) within IT/IS organizations has exploded. According to Wikipedia, a virtual machine (VM), is ‘a software implementation of a machine (i.e. a computer) that executes programs like a physical machine.’ Rapid and inexpensive virtualization of business infrastructure using VMs has led to the exponential growth of private and public cloud platforms.
Instead of attempting to configure development machines to simulate the test and production environments, which are simultaneously running development applications and often personal programs, software engineers can leverage VMs in the same way as IT/IS organizations. Free, open-source virtualization software products from Oracle and VMware offer developers the ability to easily ‘spin-up’ fresh environments to compile, deploy, and test code. Code is tested in a pristine environment, closely configured to match production, without the overhead and baggage of day-to-day development. When testing is complete, the VM is simply deleted and a new copy re-deployed for the next project.
Oracle Pre-Built Virtual Appliances
I’ve worked with a number of virtualization products, based on various Windows and Linux operating systems. Not matter the product or OS, the VM still needs to be set up just like any other new computer system, with software and configuration. However, recently I began using Oracle’s pre-built developer VMs. Oracle offers a number of pre-built VMs for various purposes, including database development, enterprise Java development, business intelligence, application hosting, SOA development, and even PHP development. The VMs, called virtual appliances, are Open Virtualization Format Archive files, built to work with Oracle VM VirtualBox. Simply import the appliance into VirtualBox and start it up.
Oracle has provided ready-made VMs that would take even the most experienced team of IT professionals days to download, install, configure, and integrate. All the configuration details, user accounts information, instructions for use, and even pre-loaded tutorials, are provided. Oracle notes on their site that these VMs are not intended for use in production. However, the VMs are more than robust enough to use as a development test environment.
Because of its similarity to my production environment, I the installed the Enterprise Java Development VM on a Windows 7 Enterprise-based development computer. The Oracle Linux 5 OS-based VM has almost everything that comprises basic enterprise test and production environment based on the Oracle/Java technology stack. The VM includes an application server, source control server, build automation server, Java SDK, two popular IDE’s, and related components. The VM includes Java JDK 1.6+, WebLogic Server, Coherence, TopLink, Subversion, Hudson, Maven, NetBeans, Enterprise Pack for Eclipse, and so forth.
Aside from a database server, the environment has everything most developers might need to develop, build, store, and host their code. If you need a database, as most of us do, you can install it into the VM, or better yet, implement the Database App Development VM, in parallel. The Database VM contains Oracle’s 11g Release 2 enterprise-level relational database, along with several related database development and management tools. Using a persistence layer (data access layer), built with the included EclipseLink, you can connect the Enterprise appliance to the database appliance.
I followed the following steps to setup my VM:
- Update (or download and install) Oracle VM VirtualBox to the latest release.
- Download (6) Open Virtualization Format Archive (OVF/.ova) files.
- Download script to combine the .ova files.
- Execute script to assemble (6) .ova files into single. ova file.
- Import the appliance (combined .ova file) into VirtualBox.
- Optional: Clone and resize the appliance’s (2) virtual machines disks (see note below).
- Optional: Add the Yum Server configuration to the VM to enable normal software updates (see instructions below).
- Change any necessary settings within VM: date/time, timezone, etc.
- Install and/or update system software and development applications within VM: Java 1.7, etc.
Issue with Small Footprint of VM
The small size of the of pre-built VM is major issue I ran into almost immediately. Note in the screen grab above of VirtualBox, the Oracle VM only has (2) 8 GB virtual machine disks (.vmdk). Although Oracle designed the VMs to have a small footprint, it was so small that I quickly filled up its primary partition. At that point, the VM was too full to apply the even the normal system updates. I switched the cache location for yum to a different partition, but then ran out of space again when yum tried to apply the updates it had downloaded to the primary partition.
Lack of disk space was a complete show-stopper for me until I researched a fix. Unfortunately, VirtualBox’s ‘VBoxManage modifyhd –resize’ command is not yet compatible with the virtual machine disk (.vmdk) format. After much trial and error, and a few late nights reading posts by others who had run into this problem, I found a fairly easy series of steps to enlarge the size of the VM. It doesn’t require you to be a complete ‘Linux Geek’, and only takes about 30 minutes of copying and restarting the VM a few times. I will included the instructions in this separate, upcoming post.
Issue with Package Updater
While solving the VM’s disk space issue, I also discoverer the VM’s Enterprise Linux System was setup with something called the Unbreakable Linux Network (ULN) Update Agent. From what I understood, without a service agreement with Oracle, I could not update the VM’s software using the standard Package Updater. However, a few quick commands I found on the Yum Server site, overcame that limitation and allowed me to update the VM’s software. Just follow the simple instructions here, for Oracle Linux 5. There are several hundred updates that will be applied, including an upgrade of Oracle Linux from 5.5 to 5.9.
Issue with Java Updates
Along with the software updates, I ran into an issue installing the latest version of Java. I attempted to install the standard Oracle package that contained the latest Java JDK, JRE, and NetBeans for Linux. Upon starting the install script, I immediately received a ‘SELinux AVC denial’ message. This security measure halted my installation with the following error: ‘The java application attempted to load /labs/java/jre1.7.0_21/lib/i386/client/libjvm.so which requires text relocation. This is a potential security problem.‘
To get around the SELinux AVC denial issue, I installed the JRE, JDK, and NetBeans separately. Although this took longer and required a number of steps, it allowed me to get around the security and install the latest version of Java.
Note I later discovered that I could have simply changed the SELinux Security Level to ‘Permissive’ in the SELinux Security and Firewall, part of the Administrative Preferences. This would have allowed the original Oracle package containing the JDK, JRE, and NetBeans, to run.