Infrastructure automation is critical for maintaining agility and efficiency in today’s fast-paced DevOps environment. By leveraging Terraform and GitLab CI/CD pipelines with self-hosted runners, you can streamline infrastructure management and achieve greater control over your deployment processes. This blog will guide you through integrating Terraform scripts into GitLab CI/CD pipelines using self-hosted runners.

Introduction to GitLab and CI/CD Pipelines

GitLab is a robust platform that provides a comprehensive suite of tools for software development, version control, and CI/CD pipelines. Its CI/CD pipelines automate the stages of software development, enabling developers to build, test, and deploy applications seamlessly.

Key Features of GitLab CI/CD:

  • Integrated pipeline editor
  • Docker support for containerized builds
  • Extensive runner management for diverse environments
  • Support for third-party integrations

CI/CD pipelines in GitLab allow teams to automate repetitive tasks, enforce consistency, and speed up application delivery.

Understanding GitLab Runners and Their Role in CI/CD

GitLab Runners are agents that execute the jobs defined in a CI/CD pipeline. These jobs can range from running tests to deploying infrastructure.

Types of GitLab Runners:

  1. Shared Runners: Managed by GitLab and shared across projects.
  2. Group Runners: Restricted to a specific group of projects.
  3. Self-Hosted Runners: Installed and managed by users, offering complete control over the execution environment.

Dive into Self-Hosted Runners: Benefits and Considerations

Self-hosted runners are particularly advantageous for specialized workloads and secure environments.

Benefits:

  • Customization: Full control over the operating environment.
  • Resource Optimization: Efficient resource allocation tailored to project needs.
  • Security: Enhanced security by keeping jobs within your network.

Considerations:

  • Maintenance of the runner infrastructure.
  • Ensuring high availability and scalability.

What is Terraform? Setting the Stage for Infrastructure Automation

Terraform is an open-source Infrastructure as Code (IaC) tool for provisioning, managing, and storing cloud infrastructure. Its declarative configuration files enable you to define your infrastructure in human-readable code.

Why Terraform?

  • Multi-cloud support
  • Reproducible and predictable configurations
  • Strong community support and extensive modules

Step-by-Step Guide to Executing Terraform Scripts via GitLab CI/CD Pipeline

1. Prerequisites

  • A GitLab account with access to a project.
  • A self-hosted GitLab runner is configured for your project.
  • Terraform was installed on the runner.

2. Creating Terraform Scripts

Write a Terraform configuration file (main.tf) for the desired infrastructure. Example:

provider “aws” {

  region = “us-east-1”

}

resource “aws_instance” “example” {

  ami           = “ami-12345678”

  instance_type = “t2.micro”

}

3. Configuring the Self-Hosted Runner

Install the GitLab Runner on your server and register it with your GitLab project. Use the following command to register:

gitlab-runner register

Provide the necessary information, including the runner’s URL and token from your GitLab project settings.

Building and Configuring Your CI/CD Pipeline for Terraform

.gitlab-ci.yml Example Configuration

Create a .gitlab-ci.yml file in your project repository:

stages:

  – plan

  – apply

variables:

  TF_STATE_BUCKET: “my-terraform-state-bucket”

  AWS_REGION: “us-east-1”

before_script:

  – export PATH=$PATH:/usr/local/bin

  – terraform –version

plan:

  stage: plan

  script:

    – terraform init

    – terraform plan -out=plan.tfplan

  artifacts:

    paths:

      – plan.tfplan

apply:

  stage: apply

  script:

    – terraform apply “plan.tfplan”

  when: manual

Implementing Terraform Infrastructure Setup in GitLab CI/CD Pipeline

  1. Initialize Terraform Backend: Configure remote state storage for collaboration:
    backend “s3” {

  bucket = “my-terraform-state-bucket”

  key    = “state/terraform.tfstate”

  region = “us-east-1”

}

  1. Define Security Credentials: Securely pass AWS credentials to the runner using environment or GitLab CI/CD variables.
  2. Automate Plan and Apply Stages: The pipeline ensures the terraform plan step runs automatically while the terraform apply step waits for manual approval.

Executing the CI/CD Pipeline and Observing Results

  • Trigger the Pipeline: Commit changes to the repository, and the pipeline starts automatically.
  • Monitor Jobs: Use the GitLab UI to track the progress of each stage.
  • Verify Infrastructure: Check your cloud provider to confirm the deployment of resources.

Conclusion: Leveraging Self-Hosted Runners for Efficient Infrastructure Management

By integrating Terraform with GitLab CI/CD pipelines and using self-hosted runners, you gain:

  • Enhanced control over deployment environments.
  • Efficient, automated infrastructure provisioning.
  • Improved security and compliance for sensitive workloads.

This approach not only accelerates infrastructure delivery but also ensures consistency and scalability.

References

Schedule automated operations for your Terraform-managed resources on AWS

Terraform