Manage and maintain GitHub with Terraform

Overview

In todays post we will take a look at one of the core components of Terraform called Providers. More specifically we will be looking at using the GitHub Provider to manage various aspects of GitHub using Terraform.

Firstly what is a terraform provider? Providers are simply plugins used in Terraform that are a logical abstraction of an upstream API responsible for understanding API interactions and exposing resources. They are used to implement resource types. At the time of this writing there are more than 2300 providers to choose from and still increasing daily!

Some popular providers you may already know about or even be using are cloud platform providers such as the AzureRM Provider for example.

However, in this post we will be looking at a specific terraform provider you may have not known about, the GitHub Provider. We will create a basic terraform configuration and use this provider to manage GitHub resources, by creating a GitHub repository and configure a branch protection rule on our repo's default branch, all through IaC (Infrastructure as Code), pretty awesome!

Pre-requisites

To get started you'll need:

• A GitHub account / Organisation
• A Personal Access Token (PAT) - See creating a personal access token.
• A Code editor such as VSCode
• Terraform

The minimum permission scopes required on the PAT token for this demo are: "repo", "read:repo_hook", "read:org", "read:discussion" and "delete_repo":

NOTE: PAT tokens are only displayed once and are sensitive, so ensure they are kept safe.

Terraform Configuration

These terraform config files can also be found on the following github repository.

Variables

### Variables.tf ###

variable "token" {
  type        = string
  description = "Specifies the GitHub PAT token or `GITHUB_TOKEN`"
  sensitive   = true
}

Main

### Main.tf ###

terraform {
  required_version = "~> 1.2.0"
  required_providers {
    github = {
      source  = "integrations/github"
      version = "~> 4.0"
    }
  }
}

provider "github" {
  token = var.token # or `GITHUB_TOKEN`
}

#Create and initialise a public GitHub Repository with MIT license and a Visual Studio .gitignore file (incl. issues and wiki)
resource "github_repository" "repo" {
  name               = "Pwd9000-Demo-Repo-2022"
  description        = "My awesome codebase"
  visibility         = "public"
  has_issues         = true
  has_wiki           = true
  auto_init          = true
  license_template   = "mit"
  gitignore_template = "VisualStudio"
}

#Set default branch 'master'
resource "github_branch_default" "master" {
  repository = github_repository.repo.name
  branch     = "master"
}

#Create branch protection rule to protect the default branch. (Use "github_branch_protection_v3" resource for Organisation rules)
resource "github_branch_protection" "default" {
  repository_id                   = github_repository.repo.id
  pattern                         = github_branch_default.master.branch
  require_conversation_resolution = true
  enforce_admins                  = true

  required_pull_request_reviews {
    required_approving_review_count = 1
  }
}

Usage

1. Clone or copy the files in this path to a local directory and open a command prompt.
2. Amend the .tfvars file with desired variables or token (Keep your tokens safe).

BUILD:

terraform init
terraform plan -out deploy.tfplan
terraform apply deploy.tfplan

DESTROY:

terraform plan -destroy -out destroy.tfplan
terraform apply destroy.tfplan

As you can see the terraform configuration we just ran using the GitHub Provider created a repository and also configured our branch protection rule on the specified default branch:

Repository created with Terraform:

Branch protection rule created with Terraform:

We have only scratched the surface of what this terraform provider can do and if you are interested to see what other resources can be built and managed in GitHub using this provider head over to the official GitHub Provider documentation.

I hope you have enjoyed this post and have learned something new. You can also find the code samples used in this blog post on my published GitHub page. ❤️

Author

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Marcel.LFollow

Dual Microsoft MVP DevOps + Azure | DevOps Architect | Technical speaker focused on Microsoft technologies, IaC and automation in Azure. Find me on GitHub: https://github.com/Pwd9000-ML