At Captiv8, we are using Amazon AWS to host most of our PHP projects. We are heavily rely on Elastic Beanstalk to help us set up PHP environment, database and load balancer. On top of that, we are also managing our own server image based on Amazon AMI. In this image, we installed additional software and packages that we need for our application. However, this approach has a drawback as it is difficult to maintain the image and track changes. Everytime you need to update the image, you have to create new server, install the new software and export it into new image. This will leave you with bunch of different images and it is hard to tell what are the things that have changed inside each image.
In order to solve these problems, I decided to find a way to automate the process. My first attempt was trying to use Chef to provision the Elastic Beanstalk environment. I have been using Chef for a while to provision my Vagrant machines. It is powerful and more convenient in compare with bash scripts. Since I am already familiar with Chef, I started looking at tutorials on how to use Chef with Elastic Beanstalk. Most of the tutorials that I found don’t provide easy way to integrate Chef with Elastic Beanstalk. One of them mentions about using AWS OpsWorks with Chef but I think it is overkill for the time being. So, I ditched Chef and start looking for another solution.
ebextensions is another solution that I found after checking the official documentation of Elastic Beanstalk. With this solution, you need to to create .ebextensions folder inside your project and create a file to define what are the packages that you want to install into the environment. Elastic Beanstalk will automatically run the script every time you deploy a new version of the application. Aside from that, you can also tell ebextensions to execute shell script in the instance or changing permission of a file. You can read more details about ebextension here: http://docs.aws.amazon.com/elasticbeanstalk/latest/dg/customize-containers-ec2.html
Here is the example of my ebextension config file:
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And this is the example of my bash script:
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Inside my ebextensions config file, I call the shell script which will install additional software. The benefit of using shell script is you have more options and it is much easier to customize the software. Since the .ebextensions folder is copied to the instance, you can tell the shell script to copy a template config file that you have prepared before hand. I hope you find this blog post useful.