Circle CI multi-version Terraform Dockerfile with Gruntwork tools (you need a Gruntwork subscription to use them)

Dockerfile

# The CircleCi builds will run in the Docker image built from this Dockerfile. To build a new image:
#
# 1. docker build -t <ACCOUNT_ID>.dkr.ecr.ca-central-1.amazonaws.com/circle-ci-build:<VERSION> --build-arg GITHUB_OAUTH_TOKEN=<YOUR_TOKEN> .
# 2. eval "$(aws ecr get-login --region ca-central-1 --no-include-email)"
# 3. docker push <ACCOUNT_ID>.dkr.ecr.ca-central-1.amazonaws.com/circle-ci-build:<VERSION>
# 4. Update the image setting in config.yml to your new VERSION.
#
# Note that we use a multi-stage build. This allows us to pass in the GITHUB_OAUTH_TOKEN secret (which we use to access
# the private gruntwork-io repos) as a build arg without it being stored in the build history. For more info, see:
#
# https://stackoverflow.com/a/40762010/483528
# https://vsupalov.com/build-docker-image-clone-private-repo-ssh-key/
#

# You must set a GitHub personal access token as a build arg. This will be used to access the private gruntwork-io
# GitHub repos
ARG GITHUB_OAUTH_TOKEN

# Module and tool versions have defaults, but you can override them
ARG GRUNTWORK_INSTALLER_VERSION=v0.0.24
ARG MODULE_CI_VERSION=v0.18.4
ARG TFENV_VERSION=1.0.2
ARG TGENV_VERSION=0.0.3
ARG TERRAFORM_VERSION=0.11.3
ARG TERRAFORM_12_VERSION=0.12.21
ARG TERRAGRUNT_VERSION=0.18.7
ARG TERRAGRUNT_12_VERSION=0.22.4

FROM ubuntu:18.04 as intermediate

ARG GITHUB_OAUTH_TOKEN
ARG GRUNTWORK_INSTALLER_VERSION
ARG MODULE_CI_VERSION
ARG TFENV_VERSION
ARG TGENV_VERSION
ARG TERRAFORM_VERSION
ARG TERRAFORM_12_VERSION
ARG TERRAGRUNT_VERSION
ARG TERRAGRUNT_12_VERSION

RUN if [ -z "$GITHUB_OAUTH_TOKEN" ]; then echo "ERROR: You must set GITHUB_OAUTH_TOKEN as a Docker build arg."; exit 1; fi

RUN apt-get update && \
    apt-get upgrade -y && \
    apt-get install -y curl wget unzip sudo libdigest-sha-perl

RUN tfenv_installdir=$(mktemp -d) && \
    cd ${tfenv_installdir} && \
    mkdir -p /opt/tfenv/${TFENV_VERSION}/ && \
    curl -LO "https://github.com/tfutils/tfenv/archive/v${TFENV_VERSION}.tar.gz" && \
    tar xf v${TFENV_VERSION}.tar.gz && \
    cd tfenv-${TFENV_VERSION}/ && \
    cp -R bin libexec share /opt/tfenv/${TFENV_VERSION}/ && \
    ln -s /opt/tfenv/${TFENV_VERSION}/bin/terraform /usr/local/bin/terraform && \
    ln -s /opt/tfenv/${TFENV_VERSION}/bin/tfenv /usr/local/bin/tfenv && \
    tfenv install ${TERRAFORM_VERSION} && \
    tfenv install ${TERRAFORM_12_VERSION} && \
    rm -Rf ${tfenv_installdir}

RUN tgenv_installdir=$(mktemp -d) && \
    cd ${tgenv_installdir} && \
    mkdir -p /opt/tfenv/${TGENV_VERSION}/ && \
    curl -LO "https://github.com/cunymatthieu/tgenv/archive/v${TGENV_VERSION}.tar.gz" && \
    tar xf v${TGENV_VERSION}.tar.gz && \
    cd tgenv-${TGENV_VERSION}/ && \
    mkdir -p /opt/tgenv/${TGENV_VERSION}/ && \
    cp -R bin libexec /opt/tgenv/${TGENV_VERSION}/ && \
    ln -s /opt/tgenv/${TGENV_VERSION}/bin/terragrunt /usr/local/bin/terragrunt && \
    ln -s /opt/tgenv/${TGENV_VERSION}/bin/tgenv /usr/local/bin/tgenv && \
    tgenv install ${TERRAGRUNT_VERSION} && \
    tgenv install ${TERRAGRUNT_12_VERSION} && \
    rm -Rf ${tgenv_installdir}

RUN curl -Ls https://raw.githubusercontent.com/gruntwork-io/gruntwork-installer/master/bootstrap-gruntwork-installer.sh | bash /dev/stdin --version "$GRUNTWORK_INSTALLER_VERSION" && \
    gruntwork-install --module-name "build-helpers" --repo "https://github.com/gruntwork-io/module-ci" --tag "$MODULE_CI_VERSION" && \
    gruntwork-install --module-name "terraform-helpers" --repo "https://github.com/gruntwork-io/module-ci" --tag "$MODULE_CI_VERSION" && \
    gruntwork-install --module-name "git-helpers" --repo "https://github.com/gruntwork-io/module-ci" --tag "$MODULE_CI_VERSION"

# This is the real Docker image that will be created in the end. It just carefully copies code from the intermediate.
FROM ubuntu:18.04

ARG TFENV_VERSION
ARG TGENV_VERSION

RUN apt-get update && \
    apt-get install -y git apt-transport-https ca-certificates curl software-properties-common jq python-pip && \
    pip install awscli

# Here we install Docker in Docker. We need it because our builds will run, well, Docker! Note that all we're really
# using is the Docker client, as CircleCi will mount a socket for us to talk to a Docker server outside of this
# container.
RUN curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add - && \
    add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" && \
    apt-get update && \
    apt-get install -y docker-ce

COPY --from=intermediate \
    /usr/local/bin/build-docker-image \
    /usr/local/bin/terraform-update-variable \
    /usr/local/bin/git-add-commit-push \
    /usr/local/bin/git-rebase \
    /usr/local/bin/

COPY --from=intermediate \
    /opt /opt/

RUN ln -s /opt/tfenv/${TFENV_VERSION}/bin/terraform /usr/local/bin/terraform && \
    ln -s /opt/tfenv/${TFENV_VERSION}/bin/tfenv /usr/local/bin/tfenv && \
    ln -s /opt/tgenv/${TGENV_VERSION}/bin/terragrunt /usr/local/bin/terragrunt && \
    ln -s /opt/tgenv/${TGENV_VERSION}/bin/tgenv /usr/local/bin/tgenv