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I’m going to create a Docker container infrastructure for CI/CD. Let’s assume we already have a Docker installation with Portainer.

Essential Containers for CI/CD:

• GitLab CE

  • Function: Code repository + pipeline management.

  • Image: gitlab/gitlab-ce

  • Ports:

    • 80: HTTP (web interface)

    • 443: HTTPS (web interface)

    • 22: SSH (clone the repository and commit to the remote)

  • Considerations:

    • Mount volumes for persistent data:
      • /etc/gitlab
      • /var/opt/gitlab
      • var/log/gitlab
• GitLab Runner

  • Function: Executes pipeline jobs (build, test, deploy, etc.)

  • Image: gitlab/gitlab-runner

  • Execution types:

    • Docker: Each job runs inside a separate container. (I’ll use this one.)

    • Shell: Jobs run directly on the host (or container).

Recommended Folder Structure:

/infra-ci-cd/
│
├── docker-compose.yml
├── gitlab/
│     ├── config/
│     ├── logs/
│     └── data/
│
└── runner/
└── config/

Container Creation

#docker-compose.yml

services:
  gitlab:
    image: gitlab/gitlab-ce:latest
    restart: always
    hostname: 'gitlab.local'
    ports:
      - '880:80'
      - '8443:443'
      - '822:22'
    volumes:
      - './gitlab/config:/etc/gitlab'
      - './gitlab/logs:/var/log/gitlab'
      - './gitlab/data:/var/opt/gitlab'

  gitlab-runner:
    image: gitlab/gitlab-runner:latest
    restart: always
    volumes:
      - './runner/config:/etc/gitlab-runner'
      - '/var/run/docker.sock:/var/run/docker.sock'

I’ve specified different ports on the local machine mapped to the necessary container ports to avoid conflicts:

ports:
  - '880:80'
  - '8443:443'
  - '822:22'

Once everything is set up, run:

docker compose up -d

This will start the containers, which we can view in Portainer.

Accessing GitLab

In the /etc/hosts file, I configure the domain gitlab.local to access it via the web browser.

#/etc/hosts

127.0.0.1 gitlab.local

To obtain the root password automatically created by GitLab, run:

docker exec -it [nom_contenidor_gitlab] grep 'Password:' /etc/gitlab/initial_root_password

You can now access http://gitlab.local:880 and log in with the root user and the retrieved password. Next, I create a blank project for the API (I’ll create a new project for the frontend in next steps):

In the next part, I’ll make the first commit to configure the pipelines.