Streamlining Multi-Component Deployments to Terraform Environments with GitHub Actions Matrices

Deploying resources in Azure often involves deploying multiple components to numerous environments, each with its own specific configuration. Managing this complexity efficiently can be challenging. However, GitHub Actions, coupled with matrices, offers a powerful solution to streamline these multi-component deployments to multiple Terraform environments. In this blog post, we’ll explore how to use matrices in GitHub Actions for managing Terraform deployments across different environments.

The Challenge of Multi-Component Deployments

In today’s cloud-native world, applications and infrastructure are rarely monolithic. They comprise various components, such as microservices, databases, and networking resources, often distributed across multiple environments like development, staging, and production. Each component may have its configuration and deployment requirements, making the management of these deployments intricate.

Enter GitHub Actions Matrices

GitHub Actions, a powerful automation tool integrated into GitHub, allows you to define flexible workflows to build, test, and deploy your code. Matrixes within GitHub Actions take this flexibility to the next level.

What are Matrices?

A matrix is a feature in GitHub Actions that enables you to run a job or workflow with multiple configurations in parallel. This is exceptionally useful when you need to deploy various components across different environments, each with its specific parameters.

Benefits of Using GitHub Matrices with Terraform

1. Enhanced Consistency

With matrices, you ensure that the same set of jobs is executed with different configurations, which promotes consistency in your Terraform deployments. Each combination in the matrix represents a unique environment and platform directory, making it easy to replicate and maintain consistent infrastructure across multiple environments.

2. Reduce Code Duplication

Matrices help reduce code duplication. Instead of defining separate jobs for each combination of environment and platform directory, you define a matrix once, simplifying your workflow configuration and making it easier to manage.

3. Highly Scalable

As your Terraform deployments grows, matrices can scale with it. You can add more configurations to the matrix as needed, allowing you to accommodate new environments or platform directories without modifying the workflow extensively.

Implementing Multi-Component Deployments with Matrices

Let’s break down the steps to implement multi-component deployments to Terraform environments using matrices within GitHub Actions:

1. Define Your Components and Environments

First, list all the components you want to deploy and the environments you want to deploy them to. For example, you might have components like “core,” “logging,” and “network,” and environments like “development” and “Production”

2. Create a Matrix in Your Workflow File

In your GitHub Actions workflow YAML file, create a matrix that includes variables for components(platform_directory) and environments. Define the values for these variables.

strategy:
  matrix:
    environment: ['development','production']
    platform_directory: ['core','logging','network']

3. Use the Matrix Variables in Your Workflow Steps

In your workflow steps, you can now utilise the matrix variables to customise your Terraform deployments for each component-environment combination. For example:

jobs:
  terraform:
    uses: ./.github/workflows/template-terraform.yaml
    strategy:
      matrix:
        environment: ['development','production']
        platform_directory: ['core','logging','network']
      fail-fast: true
      max-parallel: 1
    with:
      environment: ${{ matrix.environment }}
      backend_tf_rg: thomasthorntoncloud
      backend_tf_sa: thomasthorntontfstate
      backend_tfstate_name: ${{ matrix.environment }}-tf-github${{ matrix.platform_directory }}
      tfstate_container: github-tf-at-scale-${{ matrix.environment }}
      platform_directory: ${{ matrix.platform_directory }}
    secrets:
      CLIENT_ID: ${{ secrets.CLIENT_ID }}
      CLIENT_SECRET: ${{ secrets.CLIENT_SECRET }}
      SUBSCRIPTION_ID: ${{ secrets.SUBSCRIPTION_ID }}
      TENANT_ID: ${{ secrets.TENANT_ID }}
      DEPLOYMENT_SUBSCRIPTION_ID: ${{ secrets.DEPLOYMENT_SUBSCRIPTION_ID }}

This example demonstrates how you can use matrix variables to customise the Terraform backend configuration, ensuring that each component-environment combination has its own state file. W

With an example output of running the GitHub Action

You could easily scale this to as many components and environments as you wish.

4. Customise Further as Needed

Depending on your specific requirements, you can further customise each component’s deployment steps within the job. For instance, you may need to apply different variable files or execute specific provisioning scripts.

Conclusion

GitHub Actions matrices are a powerful tool for managing multi-component deployments to various Terraform environments efficiently. They allow you to parallelise deployments, maintain consistency, and simplify your workflow configuration. With matrices, you can embrace the complexity of modern infrastructure management while keeping your deployment process streamlined and organised. So, start harnessing the power of matrices in GitHub Actions for your Terraform deployments and witness the benefits of simplified multi-component deployment workflows.

GitHub repo containing the above example and relevant Terraform