GCP Terragrunt Demo

This simple demo illustrates the following use cases:-

• Provisions all modules recursively.
• Passes common variables to all modules.
• Creates a module dependency by passing an output value from parent module to child module.
• Stores all module state files in a GCS bucket called gcp-terragrunt-demo. This GCS bucket has the following directory structure:-

gs://gcp-terragrunt-demo                      
└── modules                         
    ├── child                       
    │   └── terraform.tfstate       
    └── parent                      
        └── terraform.tfstate       

Getting Started

• Install Terraform. After installation, run terraform --version to ensure it works.

• Install Terragrunt. After installation, run terragrunt --version to ensure it works.

• Go to [ROOT_DIR]/terragrunt.hcl and update the parameters in locals { ... } block.

• If you are running the code outside of GCP environment (ie: from your IDE instead of Cloud Shell), run the gloud commands below to get authenticated first:-

  • gcloud auth login
  • gcloud auth application-default login
  • Note: Failure to do so causes Terragrunt to throw "Missing required GCS remote state configuration project" error.

• If the GCS bucket does not exist yet, run this once:-

  • terragrunt init
  • Note: Once the GCS bucket is created, there is no need to run this command again.

• To determine changes needed to be applied to the infrastructure:-

  • terragrunt plan-all

• To provision the entire infrastructure by running each module and resolving any module dependencies:-

  • terragrunt apply-all

• To deprovision the entire infrastructure:-

  • terragrunt destroy-all