Using Docker Compose to start Terraform

Setting Up the Terraform Environment with Docker Compose

In this tutorial, we will cover how to execute Terraform using Docker Compose. This approach allows you to manage and run Terraform commands within a containerized environment using Docker Compose.

Prerequisites

Before you start, ensure you have the following installed:

• Docker: You can download and install Docker from the official Docker website.
• Docker Compose: Docker Compose is included with Docker Desktop. Alternatively, you can install it from the official Docker Compose installation guide.

Step-by-Step Guide

1. Create a Terraform Configuration File

Create a directory for your Terraform configuration and navigate into it. Inside the directory, create a file named main.tf and add your Terraform configuration. Here is an example:

provider "aws" {
  region = "us-west-2"
}

resource "aws_instance" "example" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t2.micro"
}

2. Create a Dockerfile

In the same directory, create a file named Dockerfile with the following content:

FROM hashicorp/terraform:latest

WORKDIR /workspace

COPY . /workspace

ENTRYPOINT ["terraform"]

This Dockerfile uses the official Terraform Docker image, sets the working directory to /workspace, copies your local files into the container, and sets the entry point to the Terraform binary.

3. Create a Docker Compose File

In the same directory, create a file named docker-compose.yml with the following content:

version: '3.8'

services:
  terraform:
    build: .
    volumes:
      - .:/workspace
    working_dir: /workspace
    entrypoint: ["terraform"]

4. Build the Docker Image

Open a terminal, navigate to your project directory, and build the Docker image using Docker Compose:

docker-compose build

5. Run Terraform Commands with Docker Compose

Now you can run Terraform commands using Docker Compose. Here are some examples:

Initialize Terraform

docker-compose run --rm terraform init

Validate the Terraform Configuration

docker-compose run --rm terraform validate

Plan the Terraform Deployment

docker-compose run --rm terraform plan

Apply the Terraform Configuration

docker-compose run --rm terraform apply -auto-approve

In these commands, the --rm option ensures that the container is removed after the command completes, keeping your environment clean.

Conclusion

By following these steps, you can set up and execute Terraform using Docker Compose. This method helps maintain a clean local environment and ensures consistent Terraform versions across different systems.