Why local Gitlab runner isn't detecting running Docker instance? - docker

Question

I've just installed Gitlab-runner locally on my Ubuntu machine so I can debug my pipeline without using shared runners.
I'm getting this error output:
$ docker-compose up -d --build
Couldn't connect to Docker daemon at http://docker:2375 - is it running?
If it's at a non-standard location, specify the URL with the DOCKER_HOST environment variable.
ERROR: Failed to cleanup volumes
ERROR: Job failed: exit code 1
FATAL: exit code 1
when I run docker --version I get:
Docker version 20.10.12, build e91ed57
and when I run sudo systemctl status docker I get:
● docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: active (running) since Sat 2022-01-01 20:26:25 GMT; 37min ago
TriggeredBy: ● docker.socket
Docs: https://docs.docker.com
Main PID: 1404 (dockerd)
Tasks: 20
Memory: 112.0M
CGroup: /system.slice/docker.service
└─1404 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
so it is installed and running hence the error output is confusing.
Here's my pipeline:
image: docker:stable
services:
- docker:dind
stages:
- build
- test
cache:
key: ${CI_COMMIT_REF_SLUG}
paths:
- .npm
- cache/Cypress
- node_modules
before_script:
- export REACT_APP_USERS_SERVICE_URL=http://127.0.0.1
job:
stage: build
script:
- apk add --update --no-cache gcc g++ make python2 python2-dev py-pip python3-dev docker-compose
- docker-compose up -d --build
- docker logs testdriven_e2e:latest -f
after_script:
- docker-compose down
I start the running executing gitlab-runner exec docker --docker-privileged job
Any suggestion as to why the runner is complaining about Docker not running ?
update: based on opinions from this thread https://gitlab.com/gitlab-org/gitlab-runner/-/issues/1986
image: docker:stable
variables:
DOCKER_HOST: tcp://localhost:2375
DOCKER_DRIVER: overlay2
services:
- docker:dind
stages:
- build
- test
cache:
key: ${CI_COMMIT_REF_SLUG}
paths:
- .npm
- cache/Cypress
- node_modules
before_script:
- docker info
- export REACT_APP_USERS_SERVICE_URL=http://127.0.0.1
job:
stage: build
script:
- apk add --update --no-cache gcc g++ make python2 python2-dev py-pip python3-dev curl
- curl -L "https://github.com/docker/compose/releases/download/v2.2.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
- chmod +x /usr/local/bin/docker-compose
- docker-compose up -d --build
- docker logs testdriven_e2e:latest -f
after_script:
- docker-compose down
config.toml:
concurrent = 1
check_interval = 0
[session_server]
session_timeout = 1800
[[runners]]
name = "testdriven"
url = "https://gitlab.com/"
token = "yU2yn4eUmFJ-xr3HzzmE"
executor = "docker"
[runners.custom_build_dir]
[runners.cache]
[runners.cache.s3]
[runners.cache.gcs]
[runners.cache.azure]
insecure = false
[runners.docker]
volumes = ["/var/run/docker.sock:/var/run/docker.sock", "/cache"]
cache_dir = "cache"
tls_verify = false
image = "docker:stable"
privileged = true
disable_entrypoint_overwrite = false
oom_kill_disable = false
disable_cache = false
shm_size = 0
error output:
$ docker info
Client:
Debug Mode: false
Server:
ERROR: Cannot connect to the Docker daemon at tcp://localhost:2375. Is the docker daemon running?
errors pretty printing info
ERROR: Failed to cleanup volumes
ERROR: Job failed: exit code 1
FATAL: exit code 1

Answer 1

Strangely, what worked for me was pinning down the dind version like this:
services:
- docker:18.09-dind

Answer 2

Which port is being used by docker in your system? It seems that it's running in a non-default port. Try adding this to your .gitlab-ci.yaml file, but change the 2375 port.
variables:
DOCKER_HOST: "tcp://docker:2375"