Docker:dind stops working after 12.1.0 update

It is working now, don’t forget --docker-privileged and keep docker and docker-dind versions coherent:

job:login:
  image: docker:latest
  stage: login
  tags:
    - docker-latest-dind
  services:
    - docker:dind
  before_script:
    - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
  script: ....

Working with the – docker-privileged of same version latest

gitlab-runner register -n \
  --non-interactive \
  --url https://YOUR_gitlab.com/ \
  --registration-token YOUR_REGISTRATION_TOKEN \
  --name YOUR_RUNNER_NAME
  --tag-list "docker-latest-dind" \
  --executor docker \
  --docker-image "docker:latest" \
  --docker-privileged

======== you can precise the version it is working with 19.03.12 or 18.09.7 ====

job:login19:
  image: docker:19.03.12
  stage: login
  tags:
    - docker-19.03.12-dind
  services:
    - docker:19.03.12-dind
  before_script:
    - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
  script: ....

Working with the – docker-privileged of same version ex: 19.03.12

gitlab-runner register -n \
  --non-interactive \
  --url https://YOUR_gitlab.com/ \
  --registration-token YOUR_REGISTRATION_TOKEN \
  --name YOUR_RUNNER_NAME
  --tag-list "docker-19.03.12-dind" \
  --executor docker \
  --docker-image "docker:19.03.12" \
  --docker-privileged