Starting Terraform with Docker

Setting Up the Terraform Environment in a Docker Container

In this tutorial, we will cover how to execute Terraform within a Docker container. This approach can help you manage Terraform dependencies and isolate your Terraform environment from your local machine.

Prerequisites

Before you start, ensure you have the following installed:

• Docker: You can download and install Docker from the official Docker website.

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. Build the Docker Image

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

docker build -t my-terraform-image .

4. Run Terraform Commands in the Container

Now you can run Terraform commands inside the Docker container. Here are some examples:

Initialize Terraform

docker run --rm -v $(pwd):/workspace my-terraform-image init

Validate the Terraform Configuration

docker run --rm -v $(pwd):/workspace my-terraform-image validate

Plan the Terraform Deployment

docker run --rm -v $(pwd):/workspace my-terraform-image plan

Apply the Terraform Configuration

docker run --rm -v $(pwd):/workspace my-terraform-image apply -auto-approve

In these commands, the -v $(pwd):/workspace option mounts the current directory (which contains your Terraform configuration) to the /workspace directory in the Docker container.

Conclusion

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