how to run a local docker registry inside a docker container - docker

Question

I am trying to run a process in gitlab ci that mimics the clients use case to make sure our modifications do not disrupt their use case. This is the specific job that is failing.
docker-source:
stage: build
image: carlallen/docker:buildx
services:
- name: docker:dind
command: ["dockerd", "--host=tcp://0.0.0.0:2375"]
alias: 'docker'
script:
- echo "Building..."
- docker --version
- docker buildx
- docker buildx create --use --config buildkit.toml --driver-opt network=host --buildkitd-flags '--allow-insecure-entitlement security.insecure --allow-insecure-entitlement network.host' --name test_name
- docker run -d -p 5000:5000 --restart=always --name registry registry:2
- ./build-docker.sh
$ docker --version
Docker version 19.03.14, build 5eb3275
$ docker buildx
Usage: docker buildx [OPTIONS] COMMAND
Build with BuildKit
Options:
--builder string Override the configured builder instance
Management Commands:
imagetools Commands to work on images in registry
Commands:
bake Build from a file
build Start a build
create Create a new builder instance
du Disk usage
inspect Inspect current builder instance
ls List builder instances
prune Remove build cache
rm Remove a builder instance
stop Stop builder instance
use Set the current builder instance
version Show buildx version information
Run 'docker buildx COMMAND --help' for more information on a command.
$ docker buildx create --use --config buildkit.toml --driver-opt network=host --buildkitd-flags '--allow-insecure-entitlement security.insecure --allow-insecure-entitlement network.host' --name test_name
test_name
$ docker run -d -p 5000:5000 --restart=always --name registry registry:2
docker: error during connect: Post http://docker:2375/v1.40/containers/create?name=registry: dial tcp: lookup docker on XXX.XX.X.X:53: no such host.
See 'docker run --help'.
Thank you for the help!

Answer 1

Do not override the command or entrypoint for the docker:dind image. Use environment variables to control the behavior.
variables:
DOCKER_HOST: 'docker'
DOCKER_TLS_CERTDIR: "" # disable tls, force use of port 2375
services:
- docker:dind
script:
- docker info # verify connection/server details
If this doesn't work, then you are probably using a self-hosted runner that is not configured correctly for use with docker-in-docker. You should follow the docker in docker guide and make sure you runner is setup according to the documentation.