Gitlab docker-compose Certificate issue (I think so)?

Question

GitLab

On my machine (macOS Mojave) (for learning purposes) I locally raise gitlab via docker-compose. Below is the docker-compose.yml config:

version: "3.7"

services:

    nginx:
        image: nginx
        environment:
            TZ: Europe/Moscow
        volumes:
            - './docker/nginx/:/etc/nginx/conf.d/'
            - './docker/nginx/logs:/var/log/nginx/'
        networks:
            - front
            - backend
        ports:
            - '80:80'

    apache:
        build: ./docker/apache
        environment:
            TZ: Europe/Moscow
        volumes:
            - './:/var/www/'
            - './docker/apache/php.ini:/usr/local/etc/php/php.ini'
        networks:
            - backend

    db:
        image: mysql:5.7
        volumes:
            - './docker/db:/var/lib/mysql'
            - './docker/db/logs:/var/log/mysql'
        restart: unless-stopped
        environment:
            TZ: Europe/Moscow
            MYSQL_ROOT_PASSWORD: root
            MYSQL_DATABASE: local
            MYSQL_USER: local
            MYSQL_PASSWORD: local
        networks:
            backend:
                ipv4_address: 172.20.0.4

    phpmyadmin:
        image: phpmyadmin/phpmyadmin:latest
        environment:
                - PMA_HOST=db
                - PMA_USER=root
                - PMA_PASSWORD=root
        volumes:
            - /sessions
        networks:
            - backend

    gitlab:
        image: gitlab/gitlab-ee:latest
        restart: unless-stopped
        hostname: 'gitlab.example.com'
        environment:
            TZ: Europe/Moscow
            GITLAB_OMNIBUS_CONFIG: |
                external_url 'https://gitlab.example.com'
                registry_nginx['enable'] = false
                gitlab_rails['gitlab_shell_ssh_port'] = 2022
        volumes:
            - './docker/gitlab/config:/etc/gitlab'
            - './docker/gitlab/logs:/var/log/gitlab'
            - './docker/gitlab/data:/var/opt/gitlab'
        networks:
            backend:
                ipv4_address: 172.20.0.5
        ports: 
            - '8080:80'
            - '443:443'
            - '2022:22'
            - '4567:4567'

    gitlab-runner:
        image: gitlab/gitlab-runner:latest
        restart: unless-stopped
        hostname: gitlab-runner
        depends_on:
            - gitlab
        volumes:
            - './docker/gitlab-runner/config:/etc/gitlab-runner'
            - '/var/run/docker.sock:/var/run/docker.sock'
        networks:
            backend:
                ipv4_address: 172.20.0.7
        ports:
            - '4430:443'

networks:
    front:
        external:
            name: front
    backend:
        ipam:
            driver: default
            config:
                - subnet: 172.20.0.0/16

Gitlab itself is up and running, gitlab-runner is the same, /etc/hosts has been fixed on both containers, they ping each other both by domain name and by ip, respectively.

The problem starts at the stage of registration of the Runner (gitlab-runner register) after entering all the data taken from gitlab (Admin Area -> runners -> Set up a shared Runner manually -> points 2 and 3) I get an error:

509: certificate signed by unknown authority

Below is the entire output terminal

Please enter the gitlab-ci coordinator URL (e.g. https://gitlab.com/):
https://gitlab.example.com/
Please enter the gitlab-ci token for this runner:
GdbKgRQx_vQQDgfVRYgR
Please enter the gitlab-ci description for this runner:
[gitlab-runner]: test
Please enter the gitlab-ci tags for this runner (comma separated):
test
ERROR: Registering runner... failed                 runner=GdbKgRQx status=couldn't execute POST against https://gitlab.example.com/api/v4/runners: Post https://gitlab.example.com/api/v4/runners: x509: certificate signed by unknown authority
PANIC: Failed to register this runner. Perhaps you are having network problems

Please help the community to resolve this issue.

Answer 1

The problem is explicitly described - the self-signed certificate is used.
There are detailed instructions on this on the official website .

Answer 2

It looks like you have a self-signed certificate. When registering the runner, specify the certificate ca file.
Example https://stackoverflow.com/a/48347895