Table of Contents
If you are a new or existing RightScale user, you may need some help and guidance to determine where you should focus your development efforts before you start building custom ServerTemplates and deployments. If you are looking at this document, you most likely have several unanswered questions.
Unfortunately, there is no single strategy that works for every scenario. You must take several factors into consideration before you can make the appropriate decision that best suits your business needs. This document will help guide your decision making process by making sure that you ask yourself the right questions.
There are currently three different types of ServerTemplate releases.
There are several key differences between ServerTemplates that are built with only RightScripts (e.g. 11H1 compatibility release) and the newer ServerTemplates published by RightScale that only use Chef cookbooks and recipes. The first thing to remember is that by definition, compatibility releases are not guaranteed to be compatible with one another. Although you may be able to use 11H1 scripts successfully with another compatibility release, it's important to understand that such permutations were not tested. However, scripts within the same compatibility release should be compatible. In addition to the obvious compatibility issues there are some distinct differences between the 11H1 and the latest Chef-based (v12.11 LTS and Infinity) releases.
|Built-in Cloud Support||AWS|| |
|Supported Lifecycle Period||18 months|| |
|Supported Operating Systems||CentOS 5.4 |
|Compatible with RightScripts?||Yes||Yes||Yes|
|Suitable for production environments?||Yes||Yes||Yes|
|Inherit new features, changes and support for new clouds and operating systems?||No||No||Yes|
|Can new minor releases include changes that break backwards compatibility?||No||No||Yes|
|RightScript-based "Base" ServerTemplate available?||Yes||Yes||Yes|
|Chef-based "Base" ServerTemplate available?||No||Yes||Yes|
* Additional OS support will be introduced in future Infinity releases as it becomes available.
RightScale is constantly improving its library of published ServerTemplates to make them more robust, secure, easier to use, as well as provide built-in support for multiple cloud infrastructures and operating systems. RightScale's 11H1 ServerTemplates were primarily designed with built-in support for only the AWS EC2 clouds. Built-in support for non-AWS clouds will only be available in the newer Chef-based ServerTemplates.
If possible, it is recommended that you base your ServerTemplate development off of RightScale's newest LTS (Long Term Support) or Infinity ServerTemplates that are safe to use in production environments. However, if you previously developed RightScript-based ServerTemplates you must decide whether or not to spend the time and effort needed to upgrade to a Chef-based (LTS or Infinity) release to take advantage of the new features and support.
It's also strongly recommended that you use the latest published RightImages from RightScale. See Release Notes.
If you are using a ServerTemplate that was developed with an older version of a RightImage, it is still recommended that you consider upgrading to the newer RightImages. Newer RightImages always include the latest version of RightLink, which is used for more efficient communication with the RightScale management platform, as well as newer operating systems and distributions that often include critical software updates and bug fixes. It's important to keep your environment up-to-date for security reasons. Before updating all of your existing ServerTemplates to use the latest RightImages, you should perform a basic test and launch a server using the existing ServerTemplate with a newer RightImage to verify that there are no compatibility issues.
Don't forget that you can change the frozen repository date for several of the key software distributions if you need to use an older version of a repository for backwards compatibility issues.
If you are a new user to RightScale and have not developed any custom ServerTemplates it's recommended that you start your development by using the latest Chef-based ServerTemplates published by RightScale to take advantage of the new features, bug fixes, and cloud support.
If you are an existing user of the RightScale management platform and have previously built custom ServerTemplates from scratch or cloned and modified ones from the MultiCloud Marketplace, you will need to determine if you want to use those customized SeverTemplates in your new project. If you do not plan to reuse any previous ServerTemplates, it's recommended that you start development for your new project using an existing LTS or Infinity ServerTemplate published by RightScale. If possible, you should clone and modify an existing ServerTemplate if you can find one that is similar to what you are trying to develop. If not, it's recommended that you start your development with one of the "Base" ServerTemplates. You will find "Base" ServerTemplates for both RightScript-based and Chef-based development in the MultiCloud Marketplace.
Although you may be currently satisfied with deploying your application on a single cloud infrastructure, you may want to consider the benefits of building ServerTemplates that can be used across multiple clouds for several reasons. Cost, performance, disaster recovery (e.g. launching a server into a different cloud/region), cloud SLAs or certification (e.g. ISO), private/public cloud architectures, and security are all reasons why you should strongly consider building multi-cloud ServerTemplates. Remember, if you're going to spend the time and effort to develop a custom ServerTemplate, there is no reason why you should not make it compatible across multiple clouds especially because it often does not require much more development effort.
If you are building a new ServerTemplate from scratch or customizing one from the MultiCloud Marketplace, you should start your development with one of RightScale's latest Chef-based ServerTemplates because they already have built-in support for multiple clouds.
If you want to use a RightScript-based ServerTemplate in a non-AWS cloud, you might be able to use an MCI from one of the LTS/Infinity releases. However, you will need to test the ServerTemplate to verify compatibility. Obviously if you have a script that is specific to AWS, it will fail. You will need to make sure that your RightScripts and MCIs support your chosen non-AWS cloud.
There are several different ways to make a custom ServerTemplate successfully interact with the ones that use Chef. However, if the custom ServerTemplate is used for launching a standalone application or does not need to interact with a server launched with a Chef-based ServerTemplate, you probably do not need to make any changes to your existing RightScript-based ServerTemplate.
You may have a highly customized ServerTemplate that you created to launch an application server, but you want to use the latest HAProxy load balancer and MySQL database manager ServerTemplates from the latest Chef-based release. In such cases, you will need to use the new Chef recipes to properly connect the application server to the load balancing and database tiers since the 11H1 ServerTemplates used a different methodology that was specific to AWS EC2.
If you have an existing ServerTemplate (that you customized using RightScripts) that you want to use with some of the Chef-based ServerTemplates, there are a couple of different options depending on the type and amount of customizations, and whether or not you are comfortable using Chef for development purposes.
If you are open to using Chef cookbooks and recipes instead of RightScripts, it is recommended that you base your ServerTemplate development off of RightScale's latest Chef-based ServerTemplates. If possible, you should recreate any custom RightScripts as Chef recipes. Although you can safely use RightScripts and Chef recipes in the same ServerTemplate, you might have an easier time developing and troubleshooting the scripts of your ServerTemplate if it uses only Chef recipes. Hopefully, you will find an existing Chef-based ServerTemplate that you can easily clone and modify instead of having to build a new ServerTemplate from scratch.
If you are not comfortable using Chef and would prefer to only use RightScripts for creating custom scripts, you can add the appropriate connect/disconnect Chef recipes into your existing RightScript-based ServerTemplate.
© 2006-2014 RightScale, Inc. All rights reserved.
RightScale is a registered trademark of RightScale, Inc. All other products and services may be trademarks or servicemarks of their respective owners.