Source private docker hub registry credentials from DOCKER_AUTH_CONFIG environment variable

[candrews]

For GitLab CI to use container registries requiring authentication, a common approach is to set the DOCKER_AUTH_CONFIG environment variable. This variable value is the same as that of the contents of ~/.docker/config.json.

Therefore, in GitLab CI today, to use testcontainers one has to write the contents of DOCKER_AUTH_CONFIG to ~/.docker/config.json before running the testcontainers job. For example, here's a GitLab CI job using the example private docker registry at my.private.registry:

build:
  stage: build
  services:
    - name: my.private.registry/docker:dind
      alias: docker
  variables:
    # Instruct Testcontainers to use the daemon of DinD.
    DOCKER_HOST: "tcp://docker:2375"
    DOCKER_TLS_CERTDIR: ""
    TESTCONTAINERS_HUB_IMAGE_NAME_PREFIX: my.private.registry/
  image: my.private.registry/adoptopenjdk:11-jdk-hotspot
  before_script:
    - mkdir -p "${HOME}/.docker" && echo "${DOCKER_AUTH_CONFIG}" > "${HOME}/.docker/config.json" # Testcontainers doesn't read the DOCKER_AUTH_CONFIG environment variable, only ~/.docker/config.json
  script:
    - ./gradlew build

It would be nice for testcontainers to support getting container registry authentication information from DOCKER_AUTH_CONFIG which would make it easier to use with GitLab CI.

[lrozek]

I would also like to have support for DOCKER_AUTH_CONFIG. I had to apply same workaroud as @candrews to have testcontainers be able to pull images from private repo when running inside gitlab CI / CD pipeline

[lrozek]

it looks like for .net it is already supported, at least according to https://github.com/testcontainers/testcontainers-dotnet/issues/540