Chapter 5 (final): Backend Deployment with Terraform and GitHub Actions

Setting up the GitHub Actions Workflow

To start, we'll be creating a new YAML file in the workflows folder .github/workflows/myfile.yml in your repository. This will define the workflow for the GitHub Actions by automating the deployment.

So lets break it down step by step:

name: "Terraform Deployment" # Name of the workflow

on:
  push: # Trigger the workflow on push events
    branches:
      - master # Run the workflow when pushing to the main branch

Workflow Trigger:

• The workflow is triggered on push events to the master branch.

1: Setting up the GitHub Actions Workflow

Jobs:

The workflow contains a single job named terraform-plan-and-apply.

jobs:
  terraform-plan-and-apply:
    name: "Terraform Init, plan and apply" # Name of the job
    runs-on: ubuntu-latest # Run the job on an Ubuntu environment
    env:
      AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }} # Set the AWS access key ID from secrets
      AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }} # Set the AWS secret access key from secrets
    defaults:
      run:
        working-directory: CICD-terraform # Set the working directory for all steps in the job to "infra"

Job Configuration:

name: "Terraform Init, plan and apply" - The name of the job.

runs-on: ubuntu-latest - Specifies that the job will run on an Ubuntu environment.

env: Specifies environment variables, in this case, AWS access key ID and secret access key are retrieved from GitHub Secrets.

defaults: Sets a default configuration for all steps in the job. In this case, it sets the working directory to "CICD-terraform".

Setting up the GitHub Actions Workflow

Steps:

•      steps:
            - name: Checkout
              uses: actions/checkout@v2 # Check out the repository code
  
            - name: Setup Terraform
              uses: hashicorp/setup-terraform@v1 # Set up Terraform CLI
  
            - name: Terraform Init
              id: init
              run: terraform init # Initialize the Terraform working directory
  
            - name: Terraform Validate
              id: validate
              run: terraform validate -no-color # Validate the Terraform configuration files
  
            - name: Terraform Format
              run: terraform fmt -check # Check the formatting of Terraform files
  
            - name: Terraform Plan
              id: plan
              run: terraform plan -no-color # Generate and show the execution plan
  
            - name: Terraform Apply
              run: terraform apply -auto-approve # Apply the changes in the Terraform plan without prompting for confirmation
  

  Checkout: Checks out the repository code using the actions/checkout action.

• Setup Terraform: Sets up the Terraform CLI using the hashicorp/setup-terraform action.

• Terraform Init: Initializes the Terraform working directory.

• Terraform Validate: Validates the Terraform configuration files.

• Terraform Format: Checks the formatting of Terraform files.

• Terraform Plan: Generates and shows the execution plan for Terraform changes.

• Terraform Apply: Applies the changes in the Terraform plan without prompting for confirmation (-auto-approve).

This workflow automates the process of initializing Terraform, validating configuration files, formatting Terraform files, generating an execution plan, and applying changes to the infrastructure. It's designed to run whenever there's a push to the master branch, making it a part of a continuous integration and continuous deployment (CI/CD) pipeline for managing infrastructure with Terraform.