GitLab

GitLab is a Git hosting platform built as a single application for the whole software lifecycle: repositories, merge requests, issues, GitLab CI/CD, container and package registries, security scanning and deployment environments. It is available as a SaaS (GitLab.com) or self-managed on your own servers, which is why it is popular with companies that must keep code on-premises: banks, governments, and teams in regions where cloud SaaS is restricted.

Editions

Edition License Notes
Community Edition (CE) Open source (MIT) Free, self-managed, core Git + CI/CD
Free / Premium / Ultimate Proprietary tiers (Enterprise Edition) Adds approvals rules, advanced CI, security dashboards, compliance; available on GitLab.com and self-managed
GitLab Dedicated Single-tenant SaaS For regulated organizations

GitLab CI/CD

Pipelines live in .gitlab-ci.yml at the repository root. Jobs are grouped into stages; jobs in the same stage run in parallel, and stages run in order. Jobs execute on runners: GitLab-hosted ones, or your own installed on VMs or Kubernetes, close to your data.

stages: [lint, test, deploy]

default:
  image: python:3.12-slim

lint:
  stage: lint
  script: [pip install sqlfluff, sqlfluff lint models/]

dbt-test:
  stage: test
  script: [pip install dbt-postgres, dbt build --target ci]
  rules:
    - if: $CI_PIPELINE_SOURCE == "merge_request_event"

deploy-prod:
  stage: deploy
  script: [./deploy.sh]
  environment: production
  rules:
    - if: $CI_COMMIT_BRANCH == "main"
      when: manual          # continuous delivery: a human presses the button

Useful features: needs: to build a DAG of jobs instead of strict stages, parent-child and multi-project pipelines, CI/CD components for reusable templates, and merge trains that test merge requests in sequence before merging.

GitLab vs GitHub

GitLab GitHub
Philosophy One integrated DevOps product Core platform plus a large marketplace
Self-hosting First-class, free CE GitHub Enterprise Server (paid)
CI config One .gitlab-ci.yml Many workflow files, reusable actions
Community Strong in enterprises and self-hosters Largest open-source community

Common mistakes

  • Shared runners for production deploys. Use dedicated, tagged runners with only the permissions that environment needs.
  • Unprotected CI/CD variables. Mark secrets as protected and masked so they are only exposed to pipelines on protected branches.
  • Duplicated YAML across repos. Use include: and CI/CD components instead of copying pipelines.

Learning Resources

Github BitBucket