terraform-aws-template

Terraform template for AWS

Workflow features

• Authenticating via GitHub OIDC provider
• Run terraform apply
  • Automatically running on main branch
  • Manual running on any branch
• Run terraform plan, terraform fmt and tflint
• Post terraform plan report to PullRequest comment and Job Summaries
• Slack notification

Requirements

• GitHub Actions
• Terraform v1.0+

Usage of this template

1. Install tools

• tfenv

2. Create a repository using this template

3. Setup terraform with CloudFormation

1. Download cloud_formation/setup-terraform.yml
2. Go to CloudFormation
3. Create stack with downloaded setup-terraform.yml

Parameters

• BackendBucketName (Required)
  • Name of backend bucket.
  • c.f. https://www.terraform.io/language/settings/backends/s3
• TerraformLockTableName (Required)
  • Name of lock table name for terraform.
  • c.f. https://www.terraform.io/language/settings/backends/s3
  • default: terraform-lock
• GithubOidcRoleName (Required)
  • IAM Role name for OIDC authentication
  • default: github-oidc-role
• GitHubOrgName (Required)
  • GitHub organization or user name (e.g. octocat)
• GitHubRepositoryName (Required)
  • GitHub repository name (e.g. Hello-World)
• OIDCProviderArn (optional)
  • Arn for the GitHub OIDC Provider.
  • A new provider will be created if omitted

4. Register secrets

• SLACK_WEBHOOK (optional)
  • Create from https://slack.com/apps/A0F7XDUAZ

5. Edit files

.github/workflows/terraform.yml

Edit followings

• GITHUB_OIDC_PROVIDER_ROLE
  • This is crated by cloud_formation/setup-terraform.yml. See CloudFormation stack output
• AWS_REGION
  • Same to the region where Cloudformation was executed

.terraform-version

• Upgrade to the latest version if necessary

backend.tf

Edit followings

• terraform.backend.bucket
  • Same to BackendBucketName of cloud_formation/setup-terraform.yml parameter
• terraform.backend.region
  • Same to the region where Cloudformation was executed
• terraform.backend.dynamodb_table
  • Same to TerraformLockTableName of cloud_formation/setup-terraform.yml parameter

terraform.tfvars

Edit followings

• aws_account_id
  • AWS account ID
• provider_region
  • Same to the region where Cloudformation was executed

versions.tf

Upgrade to the latest version if necessary

• terraform.required_providers.aws.version
• terraform.required_version

6. Run Terraform from local

tfenv install

terraform init

# Run followings if you upgraded providers
terraform init -upgrade
git add .terraform.lock.hcl
git commit -m "terraform init -upgrade"

git push

7. Check if GitHub Actions build is executed

Maintenance for Terraform repository

Upgrade Terraform core

1. Check latest version
   • https://github.com/hashicorp/terraform/blob/main/CHANGELOG.md
2. Edit .terraform-version
3. Run tfenv install

Upgrade Terraform providers (automatically)

1. Edit .github/dependabot.yml
2. Wait for Dependabot to create a PullRequests

Upgrade Terraform providers (manually)

1. Check latest versions
   • https://github.com/terraform-providers/terraform-provider-aws/blob/master/CHANGELOG.md
2. Edit terraform.required_providers.aws.version in versions.tf
3. Run terraform init -upgrade

Other solution

• https://github.com/sue445/terraform-gcp-template