I spent most of my time growing up doing two things, going to school and playing sports. I made many fond memories -- mostly from the latter :) -- and learned more than a few lessons over that time. Of all of those lessons, there was one in particular that stuck out in both the classroom and on the baseball diamond: Sometimes you have to get back to the basics.
In that vein, I think it is time to revisit the basics of WebSphere CloudBurst. In revisiting the basics, I am not talking about the technical basics of the appliance. Rather, I am talking about revisiting exactly why WebSphere CloudBurst exists in the first place. In other words, let's take a look at the problem domains WebSphere CloudBurst addresses, and let's discuss a little bit about how the appliance does so.
When you build application environments in WebSphere CloudBurst, there are three main elements that comprise those environments: virtual images, patterns, and script packages. It is likely that at some point you will want to export your environments from a particular WebSphere CloudBurst Appliance. This may be in order to apply version control techniques, share resources among multiple appliances, backup business-critical files, or any number of other reasons. Whatever the reason, WebSphere CloudBurst provides the necessary facilities to support both image and pattern export. WebSphere CloudBurst provides export capability for virtual images that you can access via the web console and CLI. In addition, when you download the CLI from the appliance, you get a sample script called patternToPython.jy that you can use to facilitate pattern export.
The patternToPython.jy sample produces a script that you can use to recreate the targeted pattern on an appliance of your choosing. However, before running the script to recreate the pattern on an appliance, you must ensure that any images and script packages referenced by the pattern exist on the target appliance. Since WebSphere CloudBurst enables you to easily export and import virtual images, all you have to do is account for script packages when attempting to export complete application environments from WebSphere CloudBurst. While the appliance does not directly provide the means to export script packages like it does for images and patterns, the WebSphere CloudBurst Samples Gallery includes a sample that does. You can find this sample in the CLI scripts section of the samples gallery, with the title Export a script package in a portable format.
After downloading the sample CLI script, you simply unzip the archive and use the embedded Jython script from the WebSphere CloudBurst CLI with the following command:
This command will create a ZIP file containing the contents of the script package specified by SCRIPT_PACKAGE_NAME. In addition to simply copying the contents of the specified script package into the new ZIP file, the command will trigger the creation of a cbscript.json file based on the definition of the target script package. This file defines the properties of the script package such as the execution command, command arguments, etc., and the exportScriptPackage.jy script adds it to the newly produced ZIP file.
The result of using this sample is a self-contained ZIP file that you can load into any other WebSphere CloudBurst Appliance. Since the ZIP file includes the cbscript.json file, when you load it into another appliance you do not have to define any of the properties for the script package. This eliminates the potential for definition errors as you move script packages from one appliance to the other and makes it simple to export/import script packages among appliances.
There are a couple of things about the sample worth mentioning. First, if a cbscript.json file exists in the specified script package, the export script will not create a new one. Instead, the sample simply copies the existing one into the new ZIP file. Second, the target script package's contents must be a ZIP file. That is to say, the file associated with the script package in WebSphere CloudBurst must be a ZIP. If you are using anything prior to WebSphere CloudBurst 2.0, this is not an issue since you can only associate ZIP files with script packages. However, WebSphere CloudBurst 2.0 allows you to associate any type of file (ZIP, shell script, python script, etc.) with a script package.
If you are looking to effectively export all of the components of your WebSphere CloudBurst patterns, check out this sample script. I think it will make the process a bit easier for you. As always, comments and feedback are welcome.
Customization capabilities have been very important to the design of IBM Workload Deployer going back to the beginning with WebSphere CloudBurst. Having the ability to quickly spin up environments in a cloud really does little good if those environments are not customized according to your needs. If you look at the virtual system pattern capability, it is why we always had the notion of custom images, custom patterns, and custom scripts. We give you a strong foundation, and you tweak it here and there to create what you want.
Customization is not a concept unique to virtual system patterns. The virtual application model in IBM Workload Deployer supports many different mechanisms for you to tailor your cloud-based environments. You can start with the virtual application pattern types that we ship and use any components in those patterns to build a custom environment. The patterns you build can include your own configuration (within the set of configurable parameters) and include policies that you need for your environment. In looking at just the IBM Workload Deployer Pattern for Web Applications and the IBM Workload Deployer Pattern for Databases, there are quite a number of scenarios you can support with your cloud. However, what happens when you want to go a little further and color outside the lines of what we provide?
At some point you may have heard or read that the entire virtual application pattern model resides on a pluggable architecture. In effect, this means that everything about a virtual application pattern type, from the elements that show up when building a pattern to the management interface you interact with after deployment, is customizable. The fundamental unit of customization for a virtual application pattern type is a plugin. Plugins provide the know-how in terms of installing, configuring, integrating, and managing the application types supported by a given pattern. Plugins also provide metadata that control what users see as they build and manage these patterns. In short, plugins are the source of truth for virtual application patterns!
If you looked in IBM Workload Deployer, you would find the collection of plugins that support the virtual application pattern types shipped with the offering. While that is interesting, you should also know that you can supply your own plugins. That's right. You can develop a plugin, and load it directly into the appliance. This allows you to do two very important things. First, you can extend the virtual application pattern types that come with IBM Workload Deployer with any kind of functionality you deem important. This may be additional monitoring, integration with external systems, or any number of other extensions. Second, you can create new virtual application pattern types that support your desired workloads. You can support the workloads with the software of your choosing so long as you can supply the necessary know-how in your plugins. In either case, you contribute the plugin, and your customized components become first class members of the IBM Workload Deployer landscape.
Okay, so I admit that this is not necessarily news. We have supported user-contributed plugins since the release of IBM Workload Deployer. However, there is something new that significantly lowers the barrier to entry in the custom plugin game. Early last week, IBM announced the IBM Workload Plugin Development Kit. This kit provides a set of tools and samples designed to make the construction and packaging of custom plugins a simple process. In my opinion, this reiterates our commitment to an extensible, application-centric cloud approach, and it represents a huge step forward in the industry as a whole. Be sure to check this out, and don't be shy with the comments and feedback!
If you've read anything I've written about WebSphere CloudBurst up to this point you know all about patterns. Using the appliance you can easily and quickly build, deploy, and manage these representations of your middleware application environments. Today, I want to focus in on the deployment piece in particular and take a look at how you can easily automate this process.
You can use the WebSphere CloudBurst web console to deploy patterns, and when doing so you can even schedule the deployment to happen at a later date. This scheduling capability certainly gets you on the road to an automated deployment process, but what if you want to take it one step further and eliminate the need for someone to login and manually move around the web console to schedule automated deployments? In this case, you can use either the CLI or the REST interface that WebSphere CloudBurst offers.
In this post I thought I'd take a look at using the CLI interface in order to set the stage for some nice automation around pattern deployment. It starts out with a properties file that provides details about my deployment. This includes the cloud to deploy to, the pattern to deploy, password information, and the time at which the virtual system should start.
SYSTEM_NAME_PREFIX=New App Development
TARGET_CLOUD=Default ESX group
TARGET_PATTERN=WebSphere single server
Imagine that the properties file above gets written as the result of some other action, such as the completion of your application's build process. With the properties file in place, and I'll point out that your properties file can and probably will be more robust than above, let's move on to the code that handles the deployment process based on the information in said file. First, we have a small amount of CLI code to retrieve and parse the input data (I omitted the straight-forward properties retrieval for space):
from datetime import datetime, timedelta
from java.util import Properties
from java.io import FileInputStream
// read in and retrieve properties using java.util.Properties API (i.e. props.getProperty('DEPLOYMENT_DATE'))
parsedParts = deploymentDate.split(" ")
systemName = systemName + "_" + deploymentDate
dateParts = parsedParts.split("/")
timeParts = parsedParts.split(":")
monthPart = int(dateParts)
dayPart = int(dateParts)
yearPart = int(dateParts)
hourPart = int(timeParts)
minutePart = int(timeParts)
Next is the code that actually schedules the pattern deployment:
First we get the desired deployment time and current time as datetime objects. After that, assuming the desired deployment time has not already elapsed, we calculate the difference between the desired deployment time and current time. This difference, in seconds, is then added to the result of the time.time() value to come up with a start time. After that is done, we simply retrieve the cloud that was indicated in the properties file, and then we call the runInCloud method for the pattern indicated. When calling the runInCloud method we supply the name of the virtual system that will be created, password information, and the start time we calculated earlier. As a result of this method call, a task will be generated in the target WebSphere CloudBurst Appliance and the virtual system will be started at the specified time. This will happen in an automated fashion with no human intervention required.
That's really all there is to automating the pattern deployment process using the CLI. In a more complete, end-to-end scenario you may envision the completion of one process, such as an application build process mentioned above, result in the writing of the properties file and in turn the call into the CLI to deploy a pattern. As always, feel free to send me any comments or questions.
Though I feel like we've come a long way in some of the initial confusion surrounding IBM CloudBurst and WebSphere CloudBurst, I still get quite a few basic questions on the solutions. The two most common questions are, 'Are they different products?', and 'Can/should I use them together?'. I put together a really brief overview that answers these questions and talks about the basics of the combined solution. I hope it provides a good introduction!