How Do I Execute Terraform Commands in a Docker Container?

Step 1: Make a folder to hold the Terraform configuration file.

mkdir tf
cd tf

Step 2: Make a simple configuration file.

terraform {
  required_version = "~> 1.0"
  required_providers {
    random = {
      source  = "hashicorp/random"
      version = "3.5.1"
    }
  }
}

resource "random_string" "random" {
  length = 16
}

output "random" {
  value = random_string.random.length
}

The file above will:

• Set the required version for Terraform to be anything 1.0 and above.
• Set the required set of providers to hashicorp/random and version at 3.5.1.
• Declare a resource of type "random_string", name it "random" and set its length attribute to 16 characters.
• Finally, declare an output block and name it "random".
  • The value assigned to this output is the length value.

Step 3: Make a Dockerfile at the root of the Terraform folder.

FROM golang:latest
ENV TERRAFORM_VERSION=1.2.5
RUN apt-get update && apt-get install unzip \
    && curl -Os https://releases.hashicorp.com/terraform/${TERRAFORM_VERSION}/terraform_${TERRAFORM_VERSION}_linux_amd64.zip \
    && curl -Os https://releases.hashicorp.com/terraform/${TERRAFORM_VERSION}/terraform_${TERRAFORM_VERSION}_SHA256SUMS \
    && curl https://keybase.io/hashicorp/pgp_keys.asc | gpg --import \
    && curl -Os https://releases.hashicorp.com/terraform/${TERRAFORM_VERSION}/terraform_${TERRAFORM_VERSION}_SHA256SUMS.sig \
    && gpg --verify terraform_${TERRAFORM_VERSION}_SHA256SUMS.sig terraform_${TERRAFORM_VERSION}_SHA256SUMS \
    && shasum -a 256 -c terraform_${TERRAFORM_VERSION}_SHA256SUMS 2>&1 | grep "${TERRAFORM_VERSION}_linux_amd64.zip:\sOK" \
    && unzip -o terraform_${TERRAFORM_VERSION}_linux_amd64.zip -d /usr/bin
RUN mkdir /tfcode
COPY . /tfcode
WORKDIR /tfcode

What's happening here?

The Dockerfile has instructions used for downloading Terraform executable files on a Linux machine.

Step 4: Build a Docker Image.

docker build -t terraform-container:v1.0

Step 5: Confirm the Image was created.

docker image ls

Step 6: Spin a Container from the terraform-container:v1.0 Image.

docker run -it -d --name my-tf-container terraform-container:v1.0 /bin/bash

Step 7: Confirm Container was created.

docker container ps -a

Step 8: Execute Terraform commands inside the my-tf-container Container.

docker exec my-tf-container terraform init

What's happening here?

After this point, you may continue issuing other Terraform commands like plan, apply and destroy.

I write to remember, and if, in the process, I can help someone learn about Containers, Orchestration (Docker Compose, Kubernetes), GitOps, DevSecOps, VR/AR, Architecture, and Data Management, that is just icing on the cake.