Build PHP image with gitlab-ci.yml

Question

I would like to build a Docker image when I push code to gitlab.com.

This works fine, up to a point...

gitlab-ci.yml (1)

image: php:7.4

cache:
  paths:
    - vendor/

before_script:
  - echo "Prep me"
  - apt-get update
  - apt-get install -y --no-install-recommends zip unzip gnupg2
  - php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
  - php composer-setup.php
  - php -r "unlink('composer-setup.php');"
  - curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add -
  - echo "deb https://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list

build:
  script:
    - echo "Build me"
    - composer install
    - yarn install

But nothing gets added into the Gitlab registry. So I've tried adding this to build but docker is not a recognized command.

gitlab-ci.yml (2)

    - docker pull $CI_REGISTRY_IMAGE:latest || true
    - docker build --cache-from $CI_REGISTRY_IMAGE:latest --tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA --tag $CI_REGISTRY_IMAGE:latest .
    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
    - docker push $CI_REGISTRY_IMAGE:latest

I would have thought it should be simple to get a PHP docker image spun up in no time but it seems to be difficult - unless I'm missing something?

Answer 1

The reason is that the base image of your GitLab CI right now is php:7.4 , which does not have the docker commands.

In order to achieve running docker command you will need to use an image like

image: docker:19.03.8

• See GitLab documentation for reference: https://docs.gitlab.com/ee/ci/docker/using_docker_build.html
• Also worth a look: https://docs.gitlab.com/ee/user/packages/container_registry/#container-registry-examples-with-gitlab-cicd