GitLab CI/CD

GitLab CI/CD is a tool built into GitLab for software development through the continuous methodologies:

Continuous Integration (CI)
Continuous Delivery (CD)
Continuous Deployment (CD)

NOTE: Out-of-the-box management systems can decrease hours spent on maintaining toolchains by 10% or more. Watch our "Mastering continuous software development" webcast to learn about continuous methods and how GitLab’s built-in CI can help you simplify and scale software development.

Overview

Continuous Integration works by pushing small code chunks to your application's code base hosted in a Git repository, and, to every push, run a pipeline of scripts to build, test, and validate the code changes before merging them into the main branch.

Continuous Delivery and Deployment consist of a step further CI, deploying your application to production at every push to the default branch of the repository.

These methodologies allow you to catch bugs and errors early in the development cycle, ensuring that all the code deployed to production complies with the code standards you established for your app.

For a complete overview of these methodologies and GitLab CI/CD, read the Introduction to CI/CD with GitLab.

Video demonstration of GitLab CI/CD: Demo: CI/CD with GitLab.

Getting started

GitLab CI/CD is configured by a file called .gitlab-ci.yml placed at the repository's root. This file creates a pipeline, which runs for changes to the code in the repository. Pipelines consist of one or more stages that run in order and can each contain one or more jobs that run in parallel. These jobs (or scripts) get executed by the GitLab Runner agent.

To get started with GitLab CI/CD, we recommend you read through the following documents:

If you're migrating from another CI/CD tool, check out our handy references:

You can also get started by using one of the .gitlab-ci.yml templates available through the UI. You can use them by creating a new file, choosing a template that suits your application, and adjusting it to your needs:

For a broader overview, see the CI/CD getting started guide.

Once you're familiar with how GitLab CI/CD works, see the .gitlab-ci.yml full reference for all the attributes you can set and use.

NOTE: Note: GitLab CI/CD and shared runners are enabled in GitLab.com and available for all users, limited only to the user's pipelines quota.

Concepts

GitLab CI/CD uses a number of concepts to describe and run your build and deploy.

Concept	Description
Pipelines	Structure your CI/CD process through pipelines.
Environment variables	Reuse values based on a variable/value key pair.
Environments	Deploy your application to different environments (e.g., staging, production).
Job artifacts	Output, use, and reuse job artifacts.
Cache dependencies	Cache your dependencies for a faster execution.
GitLab Runner	Configure your own GitLab Runners to execute your scripts.

Configuration

GitLab CI/CD supports numerous configuration options:

Configuration	Description
Schedule pipelines	Schedule pipelines to run as often as you need.
Custom path for `.gitlab-ci.yml`	Define a custom path for the CI/CD configuration file.
Git submodules for CI/CD	Configure jobs for using Git submodules.
SSH keys for CI/CD	Using SSH keys in your CI pipelines.
Pipeline triggers	Trigger pipelines through the API.
Pipelines for Merge Requests	Design a pipeline structure for running a pipeline in merge requests.
Integrate with Kubernetes clusters	Connect your project to Google Kubernetes Engine (GKE) or an existing Kubernetes cluster.
Optimize GitLab and Runner for large repositories	Recommended strategies for handling large repositories.
`.gitlab-ci.yml` full reference	All the attributes you can use with GitLab CI/CD.

Note that certain operations can only be performed according to the user and job permissions.

Feature set

Use the vast GitLab CI/CD to easily configure it for specific purposes. Its feature set is listed on the table below according to DevOps stages.

Feature	Description
Configure
Auto DevOps	Set up your app's entire lifecycle.
ChatOps	Trigger CI jobs from chat, with results sent back to the channel.
---+---
Verify
Browser Performance Testing	Quickly determine the performance impact of pending code changes.
CI services	Link Docker containers with your base image.
Code Quality (STARTER)	Analyze your source code quality.
GitLab CI/CD for external repositories (PREMIUM)	Get the benefits of GitLab CI/CD combined with repositories in GitHub and Bitbucket Cloud.
Interactive Web Terminals (CORE ONLY)	Open an interactive web terminal to debug the running jobs.
JUnit tests	Identify script failures directly on merge requests.
Using Docker images	Use GitLab and GitLab Runner with Docker to build and test applications.
---+---
Release
Auto Deploy	Deploy your application to a production environment in a Kubernetes cluster.
Building Docker images	Maintain Docker-based projects using GitLab CI/CD.
Canary Deployments (PREMIUM)	Ship features to only a portion of your pods and let a percentage of your user base to visit the temporarily deployed feature.
Deploy Boards (PREMIUM)	Check the current health and status of each CI/CD environment running on Kubernetes.
Feature Flags (PREMIUM)	Deploy your features behind Feature Flags.
GitLab Pages	Deploy static websites.
GitLab Releases	Add release notes to Git tags.
Review Apps	Configure GitLab CI/CD to preview code changes.
Cloud deployment	Deploy your application to a main cloud provider.
---+---
Secure
Container Scanning (ULTIMATE)	Check your Docker containers for known vulnerabilities.
Dependency Scanning (ULTIMATE)	Analyze your dependencies for known vulnerabilities.
License Compliance (ULTIMATE)	Search your project dependencies for their licenses.
Security Test reports (ULTIMATE)	Check for app vulnerabilities.

Examples

Find example project code and tutorials for using GitLab CI/CD with a variety of app frameworks, languages, and platforms on the CI Examples page.

GitLab also provides example projects pre-configured to use GitLab CI/CD.

Administration (CORE ONLY)

As a GitLab administrator, you can change the default behavior of GitLab CI/CD for:

An entire GitLab instance.
Specific projects, using pipelines settings.

References

Why GitLab CI/CD?

Learn more about:

Breaking changes

As GitLab CI/CD has evolved, certain breaking changes have been necessary. These are:

13.0

12.0

11.0

No breaking changes.

10.0

No breaking changes.

9.0

CI variables renaming for GitLab 9.0. Read about the deprecated CI variables and what you should use for GitLab 9.0+.
New CI job permissions model. See what changed in GitLab 8.12 and how that affects your jobs. There's a new way to access your Git submodules and LFS objects in jobs.