GitLab runner: Failed to connect

GitLab CI/CD
1

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Problem to solve

I am running GItLab in a docker container with ports mapped to PIv6 only. I have installed the Gitlab runner form RPM on the host, but when I try to run CI/CD job I get the error:

fatal: unable to access 'https://git.domain.dk/mads/ecc-texlive.git/': Failed to connect to git.domain.dk port 443 after 1 ms: Could not connect to server

Steps to reproduce

I have sreached the internet checked the troubleshooting section of the Gitlab runner docd, and the runner logs via journalctl, efter setting log-levet to debug, there is nothing of note. All I do i start a Docker-in-docker CI/CD-job

Configuration

The gitlab instance has the following compose:

	gitlab:
    image: gitlab/gitlab-ce:19.1.1-ce.0
    container_name: gitlab
    restart: unless-stopped
    hostname: "git.domain.dk"
    environment:
      GITLAB_OMNIBUS_CONFIG: |
        # Add any other gitlab.rb configuration here, each on its own line
        external_url 'https://git.domain.dk'
        puma['worker_processes'] = 0
        sidekiq['concurrency'] = 10
        alertmanager['enable'] = false
        gitlab_exporter['enable'] = false
        gitlab_kas['enable'] = false
        node_exporter['enable'] = false
        postgres_exporter['enable'] = false
        prometheus_monitoring['enable'] = false
        prometheus['enable'] = false
        puma['exporter_enabled'] = false
        redis_exporter['enable'] = false
        sidekiq['metrics_enabled'] = false
        letsencrypt['contact_emails'] = ['user@domain.dk'] # Optional
        registry_external_url "https://registry.domain.dk"
        pages_external_url "https://pages.domain.dk"
        gitlab_pages['namespace_in_path'] = true 

        letsencrypt['auto_renew_hour'] = "0"
        letsencrypt['auto_renew_minute'] = "30"
        letsencrypt['auto_renew_day_of_month'] = "*/28"

        gitlab_rails['smtp_enable'] = true
        gitlab_rails['smtp_address'] = "mail.domain.dk"
        gitlab_rails['smtp_port'] = 465
        gitlab_rails['smtp_enable_starttls_auto'] = false
        gitlab_rails['smtp_tls'] = true
        gitlab_rails['smtp_user_name'] = "user@domain.dk"
        gitlab_rails['smtp_password'] = "xxx"
        gitlab_rails['smtp_domain'] = "domain.dk"
        gitlab_rails['smtp_authentication'] = "login"
        gitlab_rails['smtp_openssl_verify_mode'] = 'peer'
        gitlab_rails['gitlab_email_from'] = 'gitlab@domain.dk'
        gitlab_rails['gitlab_email_reply_to'] = 'gitlab@domain.dk'
        gitlab_rails['gitlab_email_enabled'] = true
        gitlab_rails['gitlab_email_display_name'] = 'domain GitLab'

    ports:
      - "2a01:239:344:1a00::2:80:80"
      - "2a01:239:344:1a00::2:443:443"
      - "2a01:239:344:1a00::2:22:22"
    volumes:
      - "/srv/gitlab/config:/etc/gitlab"
      - "/srv/gitlab/logs:/var/log/gitlab"
      - "/srv/gitlab/data:/var/opt/gitlab"
    shm_size: "256m"

the runners configuration file is

concurrent = 1
check_interval = 0
connection_max_age = "15m0s"
shutdown_timeout = 0
log_level = "debug"

[session_server]
  session_timeout = 1800

[[runners]]
  name = "domain.dk"
  url = "https://git.domain.dk"
  id = 2
  token = "xxx"
  token_obtained_at = 2026-07-04T11:23:18Z
  token_expires_at = 0001-01-01T00:00:00Z
  executor = "docker"
  [runners.cache]
    MaxUploadedArchiveSize = 0
    [runners.cache.s3]
      AssumeRoleMaxConcurrency = 0
    [runners.cache.gcs]
    [runners.cache.azure]
  [runners.docker]
    tls_verify = false
    image = "texlive:latest"
    privileged = true
    disable_entrypoint_overwrite = false
    oom_kill_disable = false
    disable_cache = false
    volumes = ["/cache"]
    volume_keep = false
    shm_size = 0
    network_mtu = 0

and the .gitlab-ci.yml is

variables:
  DOCKER_TLS_CERTDIR: "/certs"

default:
  image: docker:29.3.1
  services:
    - docker:29.3.1-dind
  before_script:
    - docker info
  tags:
    - dind

build:
  stage: build
  rules:
    - if: $CI_PIPELINE_SOURCE == "schedule"
  script:
    - export VERSION="`date +%F`"
    - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY
    - docker build -t $CI_REGISTRY_IMAGE:$VERSION -t $CI_REGISTRY_IMAGE:latest --build-arg VERSION=ECC-$VERSION --build-arg NAME=ECC-$VERSION .
    - docker push $CI_REGISTRY_IMAGE:latest
    - docker push $CI_REGISTRY_IMAGE:$VERSION
  artifacts:
    expire_in: "1 hr"

Versions

Please select whether options apply, and add the version information.

  • Self-managed
  • GitLab.com SaaS
  • Dedicated
  • Self-hosted Runners

Versions:

Gitlab:

System information
System:		
Current User:	git
Using RVM:	no
Ruby Version:	3.3.11
Gem Version:	3.7.1
Bundler Version:4.0.10
Rake Version:	13.4.2
Redis Version:	7.2.13
Sidekiq Version:7.3.9
Go Version:	unknown

GitLab information
Version:	19.1.1
Revision:	04cd8ad1a9c
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	PostgreSQL
DB Version:	17.8
URL:		https://git.domain.dk
HTTP Clone URL:	https://git.domain.dk/some-group/some-project.git
SSH Clone URL:	git@git.domain.dk:some-group/some-project.git
Using LDAP:	no
Using Omniauth:	yes
Omniauth Providers: 

GitLab Shell
Version:	14.54.0
Repository storages:
- default: 	unix:/var/opt/gitlab/gitaly/gitaly.socket
GitLab Shell path:		/opt/gitlab/embedded/service/gitlab-shell

Gitaly
- default Address: 	unix:/var/opt/gitlab/gitaly/gitaly.socket
- default Version: 	19.1.1
- default Git Version: 	2.54.0-rc1.gb15384c

Gitlab runner:

Version:      19.1.1
Git revision: 24b9b726
Git branch:   19-1-stable
GO version:   go1.26.3
Built:        2026-06-25T11:31:53Z
OS/Arch:      linux/amd64