Terraform - Azure - GitHub Actions Runner

Table of Contents

• Introduction
• Pre-Requirements
• Azure Infrastructure
• Terraform
• Scripts
• GitHub Actions
  • GitHub Actions Runner - Terraform Apply
  • GitHub Actions Runner - Terraform Destroy

Introduction

This is a collection of Terraform scripts that show how to create Azure resources.

Pre-Requirements

• Service Principal
• Remote Backend
• terraform-azure-setup-remote-backed

Azure Infrastructure

Terraform

Azure Resources

• Resource Group
• Azure Virtual Network
• Linux Virtual Machine (default)
• Linux Virtual Machine Scale Set ()

Variables

variable "admin_username" {
  type        = string
  sensitive   = true
  description = "Linux Virtual Machine Admin User."
}

# VirtualMachine or VirtualMachineScaleSet
variable "gh_actions_runner_type" {
  type        = string
  default     = "VirtualMachine"
  description = "Type of the GitHub Runner."
}

# curl ipinfo.io/ip
variable "client_ip" {
  type = object({
    name             = string
    cidr             = string
    start_ip_address = string
    end_ip_address   = string
  })

  description = "List of client ips, can be empty."
}

variable "client_secret" {
  type        = string
  sensitive   = true
  description = "Client secret of the service principal."
}

variable "location" {
  type        = string
  default     = "westeurope"
  description = "Default Azure region, use Azure CLI notation."
}

variable "project" {
  type = object({
    customer    = string
    name        = string
    environment = string
  })

  default = {
    customer    = "azc"
    name        = "base"
    environment = "vse"
  }

  description = "Project details, like customer name, environment, etc."
}

variable "linux_virtual_machine" {
  type = object({
    size = string

    source_image_reference = object({
      publisher = string
      offer     = string
      sku       = string
      version   = string
    })
  })

  default = {
    size = "Standard_B2s"
    # size = "Standard_A2_v2"

    source_image_reference = {
      publisher = "Canonical"
      offer     = "UbuntuServer"
      sku       = "18.04-LTS"
      version   = "latest"
    }
  }

  description = "Linux Virtual Machine."
}

variable "tags" {
  type = object({
    created_by  = string
    contact     = string
    customer    = string
    environment = string
    project     = string
  })

  default = {
    created_by  = "azc-iac-payg-sp-tf"
    contact     = "contact@me"
    customer    = "Azure Cloud"
    environment = "Visual Studio Enterprise"
    project     = "GitHub Agent"
  }

  description = "Default tags for resources, only applied to resource groups."
}

variable "virtual_network" {
  type = object({
    address_space = string

    subnets = map(object({
      name          = string
      address_space = string
    }))
  })

  default = {
    address_space = "192.168.0.0/24"

    subnets = {
      virtual_machine = {
        name          = "virtual-machine"
        address_space = "192.168.0.0/28"
      }
    }
  }

  description = "VNET details."
}

Scripts

post_deployment.sh

• Updates virtual machine.
• Installs additional packages.
• Creates a user gharund for the GitHub Actions Runner service.

github_actions_runner.sh

• Template to install the GitHub Actions Runner as a service.

GitHub Actions

Secrets and variables

Secret	Description
CLIENT_ID	Client Id of the service principal
CLIENT_SECRET	Client secret of the service principal
TENANT_ID	Id of the tenant

Variable	Description
ADMIN_USERNAME	Name of the virtual machine admin user.
PROJECT_CUSTOMER	Abbreviation of the customer
PROJECT_ENVIRONMENT	Abbreviation of the environment
PROJECT_NAME	Abbreviation of the project
STATE_CONTAINER_NAME	Name of the container in the Storage Account where the state files are stored.
STATE_RESOURCE_GROUP_NAME	Name of the resource group of the Storage Account
STATE_STORAGE_ACCOUNT_NAME	Name of the Storage Account where the state files are stored.
SUBSCRIPTION_ID	Id of the Azure Subscription
USER_OBJECT_ID	Id of the user object who gets access to the Key Vault.

GitHub Actions Runner - Terraform Apply

Creates the GitHub Actions Runner.

Script

terraform_apply.yml

Inputs

Parameter	Type	Required	Default	Description
CLIENT_IP	string	true	127.0.0.1	Client IP

GitHub Actions Runner - Terraform Destroy

Destroys the GitHub Actions Runner.

Script

terraform_destroys.yml

Inputs

Parameter	Type	Required	Default	Description
CLIENT_IP	string	true	127.0.0.1	Client IP

Resources

Adding self-hosted runners

Configuring the self-hosted runner application as a service

Variables

Encrypted secrets