Apply/Destroy Terraform Modules via a Simple REST API Endpoint

Terraform is a great tool for infrastructure as code and one of my personal favorites, but while it is very easy to apply and destroy runs via a CLI and having plenty of tools to ensure Terraform runs via git push/pull requests, applying Terraform runs via an API command is a lot trickier.

That is why I created Terraformize to fill in that gap, the basic idea being that, by having the ability to create Terraform runs via a simple REST API, a developer can integrate a Terraform environment creation into their product code flow in an easy way.

Features

• REST API to run Terraform apply/destroy
• No code changes needed and it supports 100% of all Terraform modules unmodified
• Built-in support for multiple Terraform workspaces
• Can pass variables to the Terraform run via the request body (passed as a -var argument to the terraform apply or terraform destroy command)
• Supports multiple module directories
• Automatically runs terraform init before changes
• Returned response includes all the logs of stdout and stderr of Terraform for easy debugging
• Stateless (requires you use a nonlocal Terraform backend)
• Containerized
• Health check endpoint included
• Support all Terraform backends that support multiple workspaces
• No database is needed and all the data stored at the Terraform backend of your choosing
• Terraformize scales out as much as you need risk-free (requires you use a backend that supports state locking)
• AMD64 and Arm support (Arm64 not supported as there is no current binary for Terraform for it).

Possible Use Cases

• Setting up SaaS clusters and products for clients in a fully automatic way
• CI/CD integration
• Automatic system creation and\or scaling

Case Study Example

1. First, we will need a Terraform module, so create a folder named  terraformize_test :

mkdir terraformize_test

2. Now we need a valid Terraform configuration in it, if it works in Terraform it will work with Terraformize, but for this example, we will keep it simple with a single terraformize_test/test.tf   file:

resource "null_resource" "test" {

  count   = 1

}


variable "test_var" {

  description = "an example variable"

  default = "my_variable_default_value"

}


output "test" {

  value = var.test_var

}

3. We will also need to add the folder we created into the Terraformize container. This can be done in many different ways. For example, creating a container that copies our modules into a new image with the FROM  base image being Terraformize base image, but for this example, we will simply mount the folder path into the container as we run it:

docker run -d -p 80:80 -v `pwd`:/www/terraform_modules/ naorlivne/terraformize

4. Now we can run the Terraform module by simply calling it, which will run terraform apply for us (notice how we are passing variables in the body):

curl -X POST \
 http://127.0.0.1/v1/terraformize_test/my_workspace \
 -H ‘Content-Type: application/json’ \
 -H ‘cache-control: no-cache’ \
 -d ‘{
 “test_var”: “hello-world”
 }’

5. And let's create another copy of the infrastructure of the same module in another workspace:

curl -X POST \
  http://127.0.0.1/v1/terraformize_test/my_other_workspace \
  -H 'Content-Type: application/json' \
  -H 'cache-control: no-cache' \
  -d '{
    "test_var": "hello-world"
}'

6. Now that we are done, let’s delete them both (this will run terrafrom destroy for us):

curl -X DELETE \
   http://127.0.0.1/v1/terraformize_test/my_workspace \
   -H 'Content-Type: application/json' \
   -H 'cache-control: no-cache' \
   -d '{
     "test_var": "hello-world"
 }'
curl -X DELETE \
   http://127.0.0.1/v1/terraformize_test/my_other_workspace \
   -H 'Content-Type: application/json' \
   -H 'cache-control: no-cache' \
   -d '{
     "test_var": "hello-world"
 }'

Further Reading

Terraform CLI Cheat Sheet