Demo project for pre-commit with Terraform

Use pre-commit for basic Infra As Code project with Terraform:

• check documentation for Terraform code
• check syntax and validate Terraform code
• prevent committing secrets and credentials

Installation

Require Python3, Terraform >= 0.12 and terraform-docs.

Then install pre-commit and detect-secrets: pip install pre-commit detect

Install pre-commit GIT Hook: pre-commit install

Terraform Doc is up to date

cat >modules/ec2/outputs.tf <<'EOF'
output "instance_id" {
  value = aws_instance.demo.id
}
EOF
git add modules/ec2/outputs.tf
git commit -m 'Test documentation'
git diff > patch.diff
cat patch.diff

You should see modules/ec2/README.md has been modified.

Then add it to the index and commit:

git add modules/ec2/README.md
git commit -m 'Test documentation'

No secrets

cat >credentials <<'EOF'
[default]
aws_access_key_id = AKIAXXXXXXXXXXXXXXXQ
aws_secret_access_key = XXXXXXXXXXXXXXX/XXXXXXXXXXXXXXXXXXXXXXXX
EOF
git add credentials
git commit -m 'Test adding creds'

The commit must be refused. You must remove the credentials file from the GIT Tree.

git rm -f credentials

Terraform code is well formatted and correct

cat >modules/ec2/wrong-code.tf <<'EOF'
resource "aws_instance" "invalid" {
  instance_type = var.instance_type_WHICH_DOES_NOT_EXIST
  ami           = "data.aws_ami.ubuntu.id"
  tags = {
                    Name = var.name
  }
}
EOF
git add modules/ec2/wrong-code.tf
git commit -m 'Test and validate TF code'

You should see the commit has been refused due to invalid formatting in Terraform code AND invalid Terraform code.

Terraform documentation

Providers

No provider.

Inputs

No input.

Outputs

No output.