.gitlab-ci.yml

# do not use "latest" here, if you want this to work in the future
image: docker:19

services:
  - docker:dind

stages:
  - build
  - test
  - release
  - deploy

before_script:
  - docker version
  - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
  # - echo $CI_REGISTRY_USER # prints out: gitlab-ci-token
  # - echo $CI_REGISTRY_PASSWORD # prints out: [MASKED]
  # - echo $CI_REGISTRY # prints out: registry.gitlab.com
  # - echo $CI_REGISTRY_IMAGE # prints out: registry.gitlab.com/maitrungduc1410/portfolio
  # - echo $CI_COMMIT_SHA # prints out: 3a8c64173360b5c6af0b0af562b82be27534193c (commit hash)
  # - echo $CI_PROJECT_URL # prints out: https://gitlab.com/maitrungduc1410/portfolio

build:
  stage: build
  script:
    # fetches the latest image (not failing if image is not found)
    - docker pull $CI_REGISTRY_IMAGE:latest || true
    # notice the cache-from, which is going to use the image we just pulled locally
    # the built image is tagged locally with the commit SHA, and then pushed to 
    # the GitLab registry
    - >
      docker build
      --pull
      --build-arg VCS_REF=$CI_COMMIT_SHA
      --build-arg VCS_URL=$CI_PROJECT_URL
      --cache-from $CI_REGISTRY_IMAGE:latest
      --tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
      .
    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA

# .tests:
#   stage: test
#   before_script: # this before script will overwrite the parent's one
#     - apk add --no-cache py-pip python-dev libffi-dev openssl-dev gcc libc-dev make
#     - pip install docker-compose
#     - docker-compose version
#     - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
#     - docker pull $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA # pull the image we just push to register
#     - docker tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA $CI_REGISTRY_IMAGE:latest # tag this image as latest because in our docker-compose file we specify it with tag latest

# start-up-test:
#   extends: .tests
#   script:
#     - docker-compose up -d
#     - sleep 15
#     - docker-compose exec -T app pm2 status

# Here, the goal is to tag the "master" branch as "latest"
release-latest:
  variables:
    # We are just playing with Docker here. 
    # We do not need GitLab to clone the source code.
    GIT_STRATEGY: none
  stage: release
  only:
    # Only "master" should be tagged "latest"
    - master
  script:
    # Because we have no guarantee that this job will be picked up by the same runner 
    # that built the image in the previous step, we pull it again locally
    - docker pull $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
    # Then we tag it "latest"
    - docker tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA $CI_REGISTRY_IMAGE:latest
    # Then we push it.
    - docker push $CI_REGISTRY_IMAGE:latest

release-tag:
  variables:
    # Again, we do not need the source code here. Just playing with Docker.
    GIT_STRATEGY: none
  stage: release
  except:
    # We want this job to be run on other branches except master.
    - master
  script:
    - docker pull $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
    - docker tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_NAME
    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_NAME

deploy:
  stage: deploy
  variables:
    # Again, we do not need the source code here. Just playing with Docker.
    GIT_STRATEGY: none
  only:
    - master
  before_script:
    - apk update && apk add openssh-client bash
  script:
    # run ssh-agent
    - eval $(ssh-agent -s)

    # add ssh key stored in SSH_PRIVATE_KEY variable to the agent store
    - bash -c 'ssh-add <(echo "$SSH_PRIVATE_KEY")'

    - mkdir -p ~/.ssh
    - echo "$SSH_KNOWN_HOSTS" > ~/.ssh/known_hosts
    - chmod 644 ~/.ssh/known_hosts
    - >
      ssh $SSH_USER@$SSH_SERVER_IP
      "docker login -u ${CI_REGISTRY_USER} -p ${CI_REGISTRY_PASSWORD} ${CI_REGISTRY};
      cd ${PATH_TO_PROJECT};
      docker-compose down;
      docker pull ${CI_REGISTRY_IMAGE}:latest;
      docker-compose up -d;
      docker image prune -f;" # after pulling new image, the old one will be unused, so we need to remove it