Feature Flags for Infrastructure

Applying Application Feature Toggles to infrastructure

Prerequisites

• Terraform 0.13+
• Consul 1.8+
• Docker
• CDK for Terraform 0.0.14+
• Google Cloud Platform account and project
• Terraform Cloud (for remote backend storage only)

Getting Started

1. Create a service account key in GCP and save it under key.json.

2. Set the CLOUDSDK_CORE_PROJECT environment variable to your GCP project.

3. Create a directory called secrets and add the following files with secrets:

   • .terraformrc: This contains the Terraform Cloud CLI configuration file.
   • key.json: This is the Google Service Account Key
   • project: This file contains the project name for GCP.

Declarative Languages

Run docker-compose -f docker-compose-tf.yaml up.

This creates a set of toggles in a Consul instance and uses consul-template to output variables.

Update a toggle under cluster/toggles and you'll see consul-template output Terraform plan.

Imperative Languages

Go into the cdk directory and run cdktf get to generate the Typescript classes for the providers.

Warning: CDK for Terraform is in alpha. As a result, you might find some classes may not compile.

Run docker-compose -f docker-compose-cdktf.yaml up.

This creates a set of toggles in a Consul instance and uses consul-template to output variables.

Update a toggle under cluster/toggles and you'll see consul-template output the CDK for Terraform deployment.