terraform-packer-example

Terraform Packer Example

This folder contains a Terraform module that deploys resources in AWS to demonstrate how you can use Terratest to write automated tests for your AWS Terraform code. This module deploys an EC2 Instance in the AWS region specified in the aws_region variable. The EC2 Instance runs the AMI specified via the ami_id variable. It is assumed that this is an AMI built using the Packer template in packer-docker-example, which contains a simple Ruby web app. This module will configure a User Data script to start the web app, configuring it to listen for HTTP requests on the port specified by the instance_port variable and return the text specified by the instance_text variable.

Check out test/terraform_packer_example_test.go to see how you can write automated tests for this module. Note that this is an end-to-end integration test that will build the AMI, deploy it using Terraform, validate the web app is working, and then clean everything up. The test is broken down into "stages" so that, when iterating locally, you can choose to skip any of the stages by setting an environment variable. For example, if you've already built the AMI and don't want to rebuild it each time you re-run the test, you can set the environment variable SKIP_build_ami=true.

WARNING: This module and the automated tests for it deploy real resources into your AWS account which can cost you money. The resources are all part of the AWS Free Tier, so if you haven't used that up, it should be free, but you are completely responsible for all AWS charges.

Running this module manually

1. Sign up for AWS.
2. Configure your AWS credentials using one of the supported methods for AWS CLI tools, such as setting the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables. If you're using the ~/.aws/config file for profiles then export AWS_SDK_LOAD_CONFIG as "True".
3. Install Terraform and make sure it's on your PATH.
4. Install Packer and make sure it's on your PATH.
5. Follow the instructions in packer-docker-example to build an AMI. Note down the AMI ID.
6. Open variables.tf and set the ami_id variable to the ID of the AMI you just built.
7. Run terraform init.
8. Run terraform apply.
9. The instance_url output variable shows you the URL of the web server. Try opening it in your browser!
10. When you're done, run terraform destroy.

Running automated tests against this module

1. Sign up for AWS.
2. Configure your AWS credentials using one of the supported methods for AWS CLI tools, such as setting the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables. If you're using the ~/.aws/config file for profiles then export AWS_SDK_LOAD_CONFIG as "True".
3. Install Terraform and make sure it's on your PATH.
4. Install Packer and make sure it's on your PATH.
5. Install Golang and make sure this code is checked out into your GOPATH.
6. cd test
7. dep ensure
8. go test -v -run TestTerraformPackerExample