Mount: permission denied (are you root?) while using docker-in-docker workflow with Docker executor

Hi,

I am referring to Use Docker to build Docker images | GitLab to use docker-in-docker workflow with Docker executor. When I execute the pipeline, I am encountering the below issue

2020-05-23T05:48:17.105408575Z .++++
2020-05-23T05:48:17.105956361Z e is 65537 (0x010001)
2020-05-23T05:48:17.143463623Z Signature ok
2020-05-23T05:48:17.143507078Z subject=CN = docker:dind server
2020-05-23T05:48:17.143677083Z Getting CA Private Key
2020-05-23T05:48:17.157238138Z /certs/server/cert.pem: OK
2020-05-23T05:48:17.161977474Z Generating RSA private key, 4096 bit long modulus (2 primes)
2020-05-23T05:48:17.246030617Z ..................++++
2020-05-23T05:48:17.284894101Z .......++++
2020-05-23T05:48:17.284947790Z e is 65537 (0x010001)
2020-05-23T05:48:17.311669237Z Signature ok
2020-05-23T05:48:17.311705543Z subject=CN = docker:dind client
2020-05-23T05:48:17.311712394Z Getting CA Private Key
2020-05-23T05:48:17.337957567Z /certs/client/cert.pem: OK
2020-05-23T05:48:17.346384315Z mount: permission denied (are you root?)
2020-05-23T05:48:17.346794302Z Could not mount /sys/kernel/security.
2020-05-23T05:48:17.346820929Z AppArmor detection and --privileged mode might break.
2020-05-23T05:48:17.349476873Z mount: permission denied (are you root?)

cat /etc/gitlab-runner/config.toml

[[runners]]
name = “atreusdind”
url = “https://gitlab.example.com/”
token = “9kuyYJtz-81gBHDazjv4”
executor = “docker”
[runners.custom_build_dir]
[runners.docker]
tls_verify = false
image = “docker:19.03.9”
privileged = true
disable_entrypoint_overwrite = false
oom_kill_disable = false
disable_cache = false
volumes = [“/var/run/docker.sock:/var/run/docker.sock”, “/cache”]
shm_size = 0
[runners.cache]
[runners.cache.s3]
[runners.cache.gcs]
[runners.custom]
run_exec = “”

GitLab version

System information
System:
Current User: git
Using RVM: no
Ruby Version: 2.6.6p146
Gem Version: 2.7.10
Bundler Version:1.17.3
Rake Version: 12.3.3
Redis Version: 5.0.9
Git Version: 2.26.2
Sidekiq Version:5.2.7
Go Version: unknown

GitLab information
Version: 13.0.0
Revision: 6743e883eae
Directory: /opt/gitlab/embedded/service/gitlab-rails
DB Adapter: PostgreSQL
DB Version: 11.7
URL: https://gitlab.example.com
HTTP Clone URL: https://gitlab.example.com/some-group/some-project.git
SSH Clone URL: git@gitlab.example.com:some-group/some-project.git
Using LDAP: no
Using Omniauth: yes
Omniauth Providers:

GitLab Shell
Version: 13.2.0
Repository storage paths:

• default: /var/opt/gitlab/git-data/repositories
  GitLab Shell path: /opt/gitlab/embedded/service/gitlab-shell
  Git: /opt/gitlab/embedded/bin/git

Any clue regarding the above mount: permission denied (are you root?). Thanks in advance and i look forward to hearing from you.

Best Regards,

Kaushal

Hi,

Checking in again if someone can pitch in for my earlier post to this forum. Thanks in advance and I look forward to hearing from you.

Best Regards,

Kaushal

Usually you get this error if the docker image you are using has a non root user as default. since your runner is already privileged, check the source (dockerfile) of the build image.

@kaushalshriyan. I am getting the same error by following the docs Did you ever solve it? Are you running multiple runners in the same config?

@webmutation this is a docker in docker problem. The image giving this error docker image within docker.

Check the dockerfile code. Usually it is the problem. User settings.

You can fix the user and groups. If its not your image, then you need to change it.