Automatic deployment via GitLab CI

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default:

    image: "archlinux:latest"

    tags:

        - docker

    before_script:

        - pacman -Suy --noconfirm --needed openssh docker-compose

variables:

    DEPLOY_HOST: vz.fjfi.cvut.cz

    DEPLOY_USER: docker-compose-deploy

stages:

    - deploy

deploy:

    stage: deploy

    rules:

        - if: '"$DEPLOY_SSH_KEY" != "" && "$CI_COMMIT_REF_NAME" == "$CI_DEFAULT_BRANCH"'

    script:

        # Set up SSH

        - eval $(ssh-agent -s)

        - echo "$DEPLOY_SSH_KEY" | base64 -d | ssh-add - > /dev/null

        - mkdir "$HOME/.ssh"

        - echo "$DEPLOY_HOSTKEY" | base64 -d >> "$HOME/.ssh/known_hosts"

        # The native SSH support in docker/docker-compose is rather flaky:

        # https://github.com/docker/compose/issues/8544

        # The solution is to set up the unix socket forwarding via OpenSSH:

        - ssh -M -S docker-ctrl-socket -fnNT -L /tmp/docker.sock:/var/run/docker.sock "$DEPLOY_USER@$DEPLOY_HOST"

        - export DOCKER_HOST="unix:///tmp/docker.sock"

        # Deploy with docker-compose on the remote host

        - docker-compose down --remove-orphans

        - docker-compose pull --quiet

        - docker-compose up --detach --wait

        # Clean up the socket forwarding

        - ssh -q -S docker-ctrl-socket -O exit "$DEPLOY_USER@$DEPLOY_HOST"

        - rm -f /tmp/docker.sock