docker-build.yml

- job:
    name: docker
    description: Creates Docker containers in the 'dockerfiles' git repo, similiar to the way that Docker does it.
    node: docker
    logrotate:
      numToKeep: 30
    parameters:
      - string:
          name: REGISTRY
          default: <SOME THING>
          description: The name of the registry that you want to push this image to
    scm:
      - git:
          url: <SOME URL>
          credentials-id: <SOME GIT CREDENTIALS>
          skip-tag: true
          clean:
              before: false
              after:  false
          wipe-workspace: true
    properties:
      - github:
          url: <HTTP OF YOUR URL>
    builders:
      - shell: |
          #!/bin/bash
          HEAD=$(git rev-parse --verify HEAD)
          git fetch -q "$GIT_URL" "refs/heads/master"
          UPSTREAM=$(git rev-parse --verify FETCH_HEAD)
          # Detects changes in the tree and goes to build ONLY those docker containers
          diff=$(git diff --numstat "$UPSTREAM...$HEAD" -- ./ | awk '{print $3}')
          repos=($(echo $diff | awk -F '/' '{print $1}'))

          if [ "${#repos[@]}" -eq 0 ]; then
            echo "Skipping, as there are no changes in any repo"
            exit 0
          fi

          echo "Changes found. Iterating..."

          for repo in "${repos[@]}";
          do
            echo "Building lists."
            install_changed=($(git diff --numstat "$UPSTREAM...$HEAD" -- ./${repo}/install | awk '{print $3}'))
            dockerfile_changed=($(git diff --numstat "$UPSTREAM...$HEAD" -- ./${repo}/ | awk '{print $3}' | grep "Dockerfile" | awk -F '/' '{print $2}'))

            # change into the directory we want to build
            cd $repo
            # If something in the installation directory has changed, then rebuild everything.
            if [ "${#install_changed}" -gt 0 ];
            then
              echo "Installation directory changed. Rebuilding all containers for ${repo}"
              versions=$(find * -maxdepth 0 -type d ! -name install -print)

              for version in "${versions[@]}";
              do
                echo "Building ${REGISTRY}/${repo}:${version}"
                ./build.sh "${version}" "${REGISTRY}"
                if [ $? -eq 0 ];
                then
                  docker push "${REGISTRY}/${repo}:${version}"
                  docker rmi "${REGISTRY}/${repo}:${version}"
                else
                  echo "Could not push to registry."
                  exit 1
                fi
              done
            # If the dockerfile is the one to have changed, then...
            elif [ "${#dockerfile_changed[@]}" -gt 0 ] ;
            then
              echo "Building docker containers."
              for version in "${dockerfile_changed[@]}";
              do
                echo "Building ${REGISTRY}/${repo}:${version}"
                ./build.sh "${version}" "${REGISTRY}"
                if [ $? -eq 0 ];
                then
                  docker push "${REGISTRY}/${repo}:${version}"
                  docker rmi "${REGISTRY}/${repo}:${version}"
                else
                  echo "Could not push to registry."
                  exit 1
                fi
              done
            else
              echo "Couldn't find anything to build. Skipping to next."
            fi
          done
    triggers:
      - github
    wrappers:
      - ssh-agent-credentials:
          user: '<SOME GIT CREDENTIALS>'