Terraform container image

This repository builds a container image with a minimal set of tools required to apply Terraform automation.

The container includes the following:

• bash
• terraform cli
• terragrunt cli
• git cli
• jq cli
• yq v4 cli

Warning: The material contained in this repository has not been thoroughly tested. Proceed with caution.

Getting started

Prerequisites

To run this image, the following tools are required:

• docker cli
• docker backend - Docker Desktop, colima, etc

Running the client

Start the client to use it.

• To run the terraform container:

  docker run -itd --name terraform quay.io/cloudnativetoolkit/terraform

Once the client is running in the background, use it by opening a shell in it.

• To use the terraform container, exec shell into it:

  docker exec -it terraform /bin/bash

  Your terminal is now in the container.

Use this shell to run commands using the installed tools and scripts.

When you're finished running commands, to exit the client.

• To leave the terraform container shell, as with any shell:

  exit

  The container will keep running after you exit its shell.

If the client stops:

• To run the terraform container again:

  docker start terraform

The terraform container is just a Docker container, so all Docker CLI commands work.

Container registry

The build automation pushes the built container image to quay.io/cloudnativetoolkit/terraform

Floating tags

The floating image tags use the following convention:

• latest - the latest alpine version of the image (currently terraform v1.2)
• alpine - the latest alpine version of the image (currently terraform v1.2)
• fedora - the latest fedora version of the image (currently terraform v1.2)
• v1.2 - the latest alpine version of the image using terraform v1.2
• v1.1 - the latest alpine version of the image using terraform v1.1
• v1.0 - the latest alpine version of the image using terraform v1.0
• v1.2-alpine - the latest alpine version of the image using terraform v1.2
• v1.1-alpine - the latest alpine version of the image using terraform v1.1
• v1.0-alpine - the latest alpine version of the image using terraform v1.0
• v1.2-fedora - the latest fedora version of the image using terraform v1.2
• v1.1-fedora - the latest fedora version of the image using terraform v1.1
• v1.0-fedora - the latest fedora version of the image using terraform v1.0

Pinned tags

Each release within the repository corresponds to a pinned image tag that will never be moved to another image. The pinned tags use the following naming convention:

{terraform version}-{release tag}-{base OS image}

where:

• {terraform version} - is the major and minor version of the terraform cli (e.g. v1.1)
• {release tag} - is the release tag for this repository (e.g. v1.0.0)
• {base OS image} - is the base OS image (alpine or fedora)

For example:

v1.1-v1.0.0-alpine

Usage

The image can be used by referring to the image url. The following can be used to run the container image interactively:

docker run -it quay.io/cloudnativetoolkit/terraform

Development

To build the default image using the latest version of terraform on alpine, run the following:

docker build -t terraform .

Changing terraform versions

The terraform version can be changed by passing the TERRAFORM_VERSION as a build arg. For example:

docker build --build-arg TERRAFORM_VERSION=1.1.9 -t terraform:v1.1 .

Changing base OS versions

The base OS can be changed by using the Dockerfile-fedora file. For example:

docker build -f Dockerfile-fedora -t terraform:fedora .

Testing

The repository includes configuration files to test the built container images using the container-structure-test utility.

Several configuration files are defined:

• config.yaml - provides validation for the majority of the container image structure
• config-v1.0.yaml - provides validation for the terraform cli version in v1.0 builds of the image
• config-v1.1.yaml - provides validation for the terraform cli version in v1.1 builds of the image
• config-v1.2.yaml - provides validation for the terraform cli version in v1.2 builds of the image

The config files can be used in combination by providing multiple --config arguments to the container-structure-test cli.

Prerequisites

Install the container-structure-test cli by following the instructions found on container-structure-test.

Note: If you are using colima, the DOCKER_HOST environment variable will need to be set first.

1. Run colima status to get the socket value (e.g. unix:///Users/myuser/.colima/default/docker.sock)
2. Export the socket value in the DOCKER_HOST environment variable - export DOCKER_HOST="unix:///Users/myuser/.colima/default/docker.sock")

Run the tests

Run the test by providing the uri to the image and the config file(s) that will be applied. The image can exist locally or on a remote container registry.

container-structure-test test --image {image name} --config config.yaml --config {version config}

For example:

container-structure-test test --image quay.io/cloudnativetoolkit/terraform:v1.0-alpine --config config.yaml --config config-v1.0.yaml

Note: If you want to test a image from a remote container registry, the --pull argument must be included.