gitlab-org--gitlab-foss/doc/ci

stage	group	info	comments	description	type
Verify	Continuous Integration	To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments	false	Learn how to use GitLab CI/CD, the GitLab built-in Continuous Integration, Continuous Deployment, and Continuous Delivery toolset to build, test, and deploy your application.	index

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)

TIP: Tip: 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 codebase 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:

• Get started with GitLab CI/CD.
• Fundamental pipeline architectures.
• GitLab CI/CD basic workflow.
• Step-by-step guide for writing .gitlab-ci.yml for the first time.

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

• Migrating from CircleCI
• Migrating from Jenkins

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:

While building your .gitlab-ci.yml, you can use the CI/CD configuration visualization to facilate your writing experience.

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

After 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.

GitLab CI/CD and shared runners are enabled on GitLab.com and available for all users, limited only by the pipeline 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 runners to execute your scripts.
Pipeline efficiency	Configure your pipelines to run quickly and efficiently.
Test cases	Configure your pipelines to run quickly and efficiently.

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 GitLab 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 browser performance impact of pending code changes.
Load Performance Testing	Quickly determine the server performance impact of pending code changes.
CI services	Link Docker containers with your base image.
Code Quality	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.
Unit test reports	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.

See also:

• How to enable or disable GitLab CI/CD.
• Other CI administration settings.

References

Why GitLab CI/CD?

Learn more about:

• Why you might chose GitLab CI/CD.
• Reasons you might migrate from another platform.
• 5 Teams that made the switch to GitLab CI/CD

See also the Why CI/CD? presentation.

Breaking changes

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

13.0

• Remove Backported os.Expand.
• Remove Fedora 29 package support.
• Remove macOS 32-bit support.
• Removed debug/jobs/list?v=1 endpoint.
• Remove support for array of strings when defining services for Docker executor.
• Remove --docker-services flag on register command.
• Remove legacy build directory caching.
• Remove FF_USE_LEGACY_VOLUMES_MOUNTING_ORDER feature flag.
• Remove support for Windows Server 1803.

12.0

• Use refspec to clone/fetch Git repository.
• Old cache configuration.
• Old metrics server configuration.
• Remove FF_K8S_USE_ENTRYPOINT_OVER_COMMAND.
• Remove Linux distributions that reach EOL.
• Update command line API for helper images.
• Remove old git clean flow.

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.