“Cannot connect to the Docker daemon.” error while building docker image in gitlab-ci docker executor

Question

I'm following the instructions here:

http://doc.gitlab.com/ee/ci/docker/using_docker_build.html#use-docker-in-docker-executor

I definitely have "privileged = true" in my config.toml file and this is the relavent part of my .gitlab-ci.yml:

 sampleProjectDockerBuild:
  stage: docker
  image: docker:latest
  services:
    - docker:dind
  before_script:
    - docker info
  script:
    - docker build -t my-docker-image .

But I am getting the following error:

gitlab-ci-multi-runner 1.1.3 (a470667)
Using Docker executor with image docker:latest ...
Pulling docker image docker:dind ...
Starting service docker:dind ...
Waiting for services to be up and running...
Pulling docker image docker:latest ...

...

$ docker info
Cannot connect to the Docker daemon. Is the docker daemon running on this host?

ERROR: Build failed: exit code 1

Am I missing something?

Answer 1

Maybe docker-compose don't equal version to docker-machine. You sure both save version

Answer 2

The runner was a CentOS 6 machine, which has recently lost support. I tried this again on a CentOS 7 machine and everything just worked.