Gitlab pipeline, kubernetes runner - How to configure - docker

Question

I have problem with running docker in kubernetes runner.
I've installed kubernetes runner with helm and set privileged mode to true
runners:
config: |
[[runners]]
[runners.kubernetes]
namespace = "{{.Release.Namespace}}"
image = "ubuntu:20.04"
privileged = true
allow_privilege_escalation = true
I've created simple .gitlab-ci.yaml for test
stages:
- docker_test
services:
- docker:dind
docker_test:
stage: docker_test
image: docker:latest
variables:
DOCKER_HOST: "tcp://docker:2375"
script:
- docker version
But when I fire this pipeline I'm gettint error
Running with gitlab-runner 14.6.0 (5316d4ac)
on gitlab-runner-gitlab-runner-5cc654bdf7-gjfvm augRojS5
Preparing the "kubernetes" executor
00:00
Using Kubernetes namespace: gitlab-runner
Using Kubernetes executor with image docker:latest ...
Using attach strategy to execute scripts...
Preparing environment
00:06
Waiting for pod gitlab-runner/runner-augrojs5-project-30333904-concurrent-0k66kk to be running, status is Pending
Waiting for pod gitlab-runner/runner-augrojs5-project-30333904-concurrent-0k66kk to be running, status is Pending
ContainersNotReady: "containers with unready status: [build helper svc-0]"
ContainersNotReady: "containers with unready status: [build helper svc-0]"
Running on runner-augrojs5-project-30333904-concurrent-0k66kk via gitlab-runner-gitlab-runner-5cc654bdf7-gjfvm...
Getting source from Git repository
00:03
Fetching changes with git depth set to 50...
Initialized empty Git repository in /builds/gurita/gurita-core/.git/
Created fresh repository.
Checking out fe720f2f as main...
Skipping Git submodules setup
Executing "step_script" stage of the job script
00:00
$ docker version
Client:
Version: 20.10.12
API version: 1.41
Go version: go1.16.12
Git commit: e91ed57
Built: Mon Dec 13 11:40:57 2021
OS/Arch: linux/amd64
Context: default
Experimental: true
Cannot connect to the Docker daemon at tcp://docker:2375. Is the docker daemon running?
Cleaning up project directory and file based variables
00:01
ERROR: Job failed: command terminated with exit code 1
I tried to set without variable but at this case there is no /var/run/docker.sock.

Answer 1

You need to mount the host's docker socket:
[runners.kubernetes]
image = "ubuntu:18.04"
privileged=true
[[runners.kubernetes.volumes.host_path]]
name = "docker-socket"
mount_path = "/var/run/docker.sock"
read_only = false
host_path = "/var/run/docker.sock"
(NOTE: This is from one of my old gitlab installations, I haven't tested this against the latest release)
Here's my full Runner block. You can swapping my config in for yours (make a backup of your old config first) and see if it works. Obviously change things as needed -- for example I use a specific node pool, hence the node_selector and node_tolerations sections
## Installation & configuration of gitlab/gitlab-runner
## See requirements.yaml for current version
gitlab-runner:
install: true
rbac:
create: true
runners:
locked: false
privileged: true
cache:
secretName: google-application-credentials
config: |
[[runners]]
[runners.feature_flags]
FF_GITLAB_REGISTRY_HELPER_IMAGE = true
FF_SKIP_DOCKER_MACHINE_PROVISION_ON_CREATION_FAILURE = true
[runners.kubernetes]
image = "ubuntu:18.04"
privileged=true
[[runners.kubernetes.volumes.host_path]]
name = "docker-socket"
mount_path = "/var/run/docker.sock"
read_only = false
host_path = "/var/run/docker.sock"
[runners.kubernetes.node_selector]
"cloud.google.com/gke-nodepool" = "gitlab-runners"
[runners.kubernetes.node_tolerations]
"appName=gitlab" = "NoExecute"
{{- if .Values.global.minio.enabled }}
[runners.cache]
Type = "gcs"
Path = "gitlab-runner"
Shared = true
[runners.cache.gcs]
BucketName = "runner-cache"
{{ end }}
podAnnotations:
gitlab.com/prometheus_scrape: "true"
gitlab.com/prometheus_port: 9252

Answer 2

Thank you for your hint about mounting docker.sock.
this worked for me
runners:
config: |
[[runners]]
[runners.kubernetes]
image = "ubuntu:20.04"
privileged = true
[[runners.kubernetes.volumes.empty_dir]]
name = "docker-emptydir"
mount_path = "/var/run"
medium = "Memory"
Thanks again