terraform-provider-demo

Demonstrating a custom Terraform provider that creates/updates file content inside a GitHub repository.

Disclaimer

This custom provider is not recommended for production environments.

I have written this provider for demonstration purposes, there is still room for improvement.

Environment Details

The following instructions are tested and based on:

• Fedora 31
• Terraform 0.12.19
• Go 1.13.5

Prerequisites

Some initial requirements.

Terraform Setup

If Terraform is not already installed:

# or find the latest: https://releases.hashicorp.com/terraform/
wget https://releases.hashicorp.com/terraform/0.12.19/terraform_0.12.19_linux_amd64.zip
unzip terraform_0.12.19_linux_amd64.zip
sudo unzip terraform_0.12.19_linux_amd64.zip -d /usr/local/bin/

Go Setup

Firstly, install Go:

sudo dnf install golang

Terraform Core and Terraform provider development requires using the Go toolchain in the new "modules mode", which in current versions of Go is not the default. (Atkins, 2019)

Execute the following to enable the modules mode:

go mod init mymodule/test

The Go build will now be able to download all required dependencies.

Usage

How to use this custom Terraform provider.

Building Source

Whenever changes are made to the provider, rebuild the binary:

go build -o terraform-provider-demo

Authentication

As opposed to exposing your GitHup Personal Access Token inside your Terraform modules, you can export it as an environment variable:

export GITHUB_TOKEN="<GITHUB_TOKEN>"

Terraform Usage

This directory contains a simple main.tf that defines the custom resource, demo_repo_content, to be created on apply. Modify the main.tf to configure your GitHub repository details.

Initialize the custom provider (and any other providers) to be used here, then run apply:

terraform init
terraform apply

You will then be prompted to review and confirm that demo_repo_content.main will be created.

If everything succeeds, the file with the content defined in your Terraform module(s) will be created/updated in your desired GitHub repository and branch.

Refer to Installing Plugins for configuring this custom provider.