Terraform vs Cloudformation — First Thoughts

Building out AWS infrastructures by hand is not something that should be taken on lightly. Just as in building out a Data Center or service in any cloud environment (Google, VMWare, etc), building out a bunch of systems by hand is a good way to inherit a bunch of technical debt and a headache or three. On top of that, it is slow and cumbersome to build out servers in a manual fashion, and since it is done manually, it is easy to make mistakes and introduce snowflakes into your environment. Instead, we need to address the build out with automation tooling.

There are a number of options to build out an infrastructure in AWS. As such, this is not to say that Terraform and Cloudformation are the only options. However, they are two options that have decent support, are mature, and are used by more than one person. Another option is to roll your own solution going straight against the AWS api in any number of languages. That however, is potentially more trouble than it is worth. Maybe later we can discuss ways to build out and probe an environment with your own tools, but for now let us stick to talking about Terraform and CloudFormation.

What are CloudFormation and Terraform? 

CloudFormation is a tool written by Amazon Web Services as a way to create and control a collection of resources within AWS. It is under continuous development and improvement by the AWS team, for use on AWS.

Terraform is a product produced by Hashicorp. The goal is a tool that is designed to treat your infrastructure as code. It is designed to work with multiple cloud providers, and be versioned under source control like any of your code projects.

CloudFormation

I have used cloud formation to build out entire environments, single servers, and for testing. It is a very useful tool for what it does, with a few limitations.

 

CloudFormation is AWS specific. Very shortly after a new service comes out, it is supported via CloudFormation. This means that almost any service you are going to want to use with CloudFormation will be available.

There are a plethora of examples on how to use CloudFormation. AWS is great about providing examples, and they do not fall short when it comes to Cloudformation. They have examples on how to use various services, and even how to integrate with Chef and Puppet.

A downside of CloudFormation is that if you don’t manage all your services via CloudFormation you can end up in a state where you cause CloudFormation to get into a hung state. This can happen if you delete a resource that was created in CloudFormation.

Terraform

Terraform has been designed to be cloud agnostic with different providers. This means that if you are in a mixed environment, you can use the same tool to build out your infrastructure on AWS, GCC, or Azure. This is definitely a plus if you are not dedicated to AWS, but this can be a disadvantage if you want to use Terraform to manage a new service.

Because Terraform is not designed specifically for AWS, you may end up in a situation where you will have to write your own plugin to manage a service/resource inside of AWS. It is great that it is open source, and anyone can add features, but a bit of a pain in that you may be stuck waiting on new AWS features to be supported.

Support is mixed. There are not as many examples on how to use Terraform as there are for Cloudformation. You may end up using a search engine to try and find examples for the features that you want to use.

But, it has been designed to treat your infrastructure as code, and so it does offer ways to track your environment, and inputs.

Conclusion

At this point it is to early to say. I am going to have to think about it more, and do a deep dive into both Terraform and CloudFormation.