In the world of infrastructure as code, the biggest divide seems to come in the war between Hashicorp’s Terraform vs. CloudFormation in AWS. Both tools can help you deploy new cloud infrastructure in a repeatable way, but have some pretty big differences that can mean the difference between a smooth rollout or a never ending battle with your tooling. Let’s look at some of the similarities and some of the differences between the two.
While the tools have some very unique features, they also share some common aspects. In general, both CloudFormation and Terraform help you provision new AWS resources from a text file. This means you can iterate and manage the entire infrastructure stack the same as you would any other piece of code. Both tools are also declarative, which means you define what you want the end goal to be, rather than saying how to get there (such as with tools like Chef or Puppet). This isn’t necessarily a good or bad thing, but is good to know if you’re used to other config management tools.
Unique Characteristics of CloudFormation
One of the biggest benefits of using CloudFormation is that it is an AWS product, which means it has tighter tie-ins to other AWS services. This can be a huge benefit if you’re all-in on AWS products and services, as this can help you maximize your cost-effectiveness and efficiency within the AWS ecosystem. CloudFormation also makes use of either YAML or JSON as the format for your code, which might be familiar to those with dev experience. Along the same lines, each change to your infrastructure is a changeset from the previous one, so devs will feel right at home.
There are some additional tools available around CloudFormation, such as:
- Stacker – for handling multiple CloudFormation stacks simultaneously
- Troposphere -if you prefer python for creating your configuration files
- StackMaster – if you prefer Ruby
- Sceptre – for organizing CloudFormation stacks into environments
Unique Characteristics of Terraform
Just as being an AWS product is a benefit of CloudFormation if you’re in AWS, the fact that Terraform isn’t affiliated with any particular cloud makes it much more suited for multi-cloud and hybrid-cloud environments, and of course, for non-AWS clouds. There are Terraform modules for almost any major cloud or hypervisor in the Terraform Registry, and you can even write your own modules if necessary.
Terraform treats all deployed infrastructure as a state, with any subsequent changes to any particular piece being an update to the state (unlike the changesets mentioned above for CloudFormation). This means you can keep the state and share it, so others know what your stack should look like, and also means you can see what would change if you modify part of your configuration before you actually decide to do it. The Terraform configuration files are written in HCL (Hashicorp Configuration Language), which some consider easier to read than JSON or YAML.
More on Terraform: How to Use Terraform Provisioning and ParkMyCloud to Manage AWS
Terraform vs. CloudFormation: Which to choose?
The good news is that if you’re trying to decide between Terraform vs. CloudFormation, you can’t really go wrong with either. Both tools have large communities with lots of support and examples, and both can really get the job done in terms of creating stacks of resources in your environments. They are both also free, with CloudFormation having no costs (aside from the infrastructure that gets created) and Terraform being open-source while offering a paid Enterprise version for additional collaboration and governance options. Each has their pros and cons, but using either one will help you scale up your infrastructure and manage it all as code.