Configuration of your builds with .gitlab-ci.yml

From version 7.12, GitLab CI uses a YAML file (.gitlab-ci.yml) for the project configuration. It is placed in the root of your repository and contains definitions of how your project should be built.

The YAML file defines a set of jobs with constraints stating when they should be run. The jobs are defined as top-level elements with a name and always have to contain the script clause:

job1:
  script: "execute-script-for-job1"

job2:
  script: "execute-script-for-job2"

The above example is the simplest possible CI configuration with two separate jobs, where each of the jobs executes a different command.

Of course a command can execute code directly (./configure;make;make install) or run a script (test.sh) in the repository.

Jobs are used to create builds, which are then picked up by runners and executed within the environment of the runner. What is important, is that each job is run independently from each other.

.gitlab-ci.yml

The YAML syntax allows for using more complex job specifications than in the above example:

image: ruby:2.1
services:
  - postgres

before_script:
  - bundle_install

stages:
  - build
  - test
  - deploy

job1:
  stage: build
  script:
    - execute-script-for-job1
  only:
    - master
  tags:
    - docker

There are a few reserved keywords that cannot be used as job names:

Keyword Required Description
image no Use docker image, covered in Use Docker
services no Use docker services, covered in Use Docker
stages no Define build stages
types no Alias for stages
before_script no Define commands that run before each job's script
variables no Define build variables
cache no Define list of files that should be cached between subsequent runs

image and services

This allows to specify a custom Docker image and a list of services that can be used for time of the build. The configuration of this feature is covered in separate document: Use Docker.

before_script

before_script is used to define the command that should be run before all builds, including deploy builds. This can be an array or a multi-line string.

stages

stages is used to define build stages that can be used by jobs. The specification of stages allows for having flexible multi stage pipelines.

The ordering of elements in stages defines the ordering of builds' execution:

  1. Builds of the same stage are run in parallel.
  2. Builds of next stage are run after success.

Let's consider the following example, which defines 3 stages:

stages:
  - build
  - test
  - deploy
  1. First all jobs of build are executed in parallel.
  2. If all jobs of build succeeds, the test jobs are executed in parallel.
  3. If all jobs of test succeeds, the deploy jobs are executed in parallel.
  4. If all jobs of deploy succeeds, the commit is marked as success.
  5. If any of the previous jobs fails, the commit is marked as failed and no jobs of further stage are executed.

There are also two edge cases worth mentioning:

  1. If no stages is defined in .gitlab-ci.yml, then by default the build, test and deploy are allowed to be used as job's stage by default.
  2. If a job doesn't specify stage, the job is assigned the test stage.

types

Alias for stages.

variables

Note: Introduced in GitLab Runner v0.5.0.

GitLab CI allows you to add to .gitlab-ci.yml variables that are set in build environment. The variables are stored in the git repository and are meant to store non-sensitive project configuration, for example:

variables:
  DATABASE_URL: "postgres://postgres@postgres/my_database"

These variables can be later used in all executed commands and scripts.

The YAML-defined variables are also set to all created service containers, thus allowing to fine tune them.

cache

cache is used to specify a list of files and directories which should be cached between builds.

By default the caching is enabled per-job and per-branch.

If cache is defined outside the scope of the jobs, it means it is set globally and all jobs will use its definition.

To cache all git untracked files and files in binaries:

cache:
  untracked: true
  paths:
  - binaries/

cache:key

Note: Introduced in GitLab Runner v1.0.0.

The key directive allows you to define the affinity of caching between jobs, allowing to have a single cache for all jobs, cache per-job, cache per-branch or any other way you deem proper.

This allows you to fine tune caching, allowing you to cache data between different jobs or even different branches.

The cache:key variable can use any of the predefined variables.


Example configurations

To enable per-job caching:

cache:
  key: "$CI_BUILD_NAME"
  untracked: true

To enable per-branch caching:

cache:
  key: "$CI_BUILD_REF_NAME"
  untracked: true

To enable per-job and per-branch caching:

cache:
  key: "$CI_BUILD_NAME/$CI_BUILD_REF_NAME"
  untracked: true

To enable per-branch and per-stage caching:

cache:
  key: "$CI_BUILD_STAGE/$CI_BUILD_REF_NAME"
  untracked: true

If you use Windows Batch to run your shell scripts you need to replace $ with %:

cache:
  key: "%CI_BUILD_STAGE%/%CI_BUILD_REF_NAME%"
  untracked: true

Jobs

.gitlab-ci.yml allows you to specify an unlimited number of jobs. Each job must have a unique name, which is not one of the Keywords mentioned above. A job is defined by a list of parameters that define the build behavior.

job_name:
  script:
    - rake spec
    - coverage
  stage: test
  only:
    - master
  except:
    - develop
  tags:
    - ruby
    - postgres
  allow_failure: true
Keyword Required Description
script yes Defines a shell script which is executed by runner
stage no (default: test) Defines a build stage
type no Alias for stage
only no Defines a list of git refs for which build is created
except no Defines a list of git refs for which build is not created
tags no Defines a list of tags which are used to select runner
allow_failure no Allow build to fail. Failed build doesn't contribute to commit status
when no Define when to run build. Can be on_success, on_failure or always
artifacts no Define list build artifacts
cache no Define list of files that should be cached between subsequent runs

script

script is a shell script which is executed by the runner. For example:

job:
  script: "bundle exec rspec"

This parameter can also contain several commands using an array:

job:
  script:
    - uname -a
    - bundle exec rspec

stage

stage allows to group build into different stages. Builds of the same stage are executed in parallel. For more info about the use of stage please check stages.

only and except

only and except are two parameters that set a refs policy to limit when jobs are built:

  1. only defines the names of branches and tags for which the job will be built.
  2. except defines the names of branches and tags for which the job will not be built.

There are a few rules that apply to the usage of refs policy:

  • only and except are inclusive. If both only and except are defined in a job specification, the ref is filtered by only and except.
  • only and except allow the use of regular expressions.
  • only and except allow the use of special keywords: branches and tags.
  • only and except allow to specify a repository path to filter jobs for forks.

In the example below, job will run only for refs that start with issue-, whereas all branches will be skipped.

job:
  # use regexp
  only:
    - /^issue-.*$/
  # use special keyword
  except:
    - branches

The repository path can be used to have jobs executed only for the parent repository and not forks:

job:
  only:
    - branches@gitlab-org/gitlab-ce
  except:
    - master@gitlab-org/gitlab-ce

The above example will run job for all branches on gitlab-org/gitlab-ce, except master.

tags

tags is used to select specific runners from the list of all runners that are allowed to run this project.

During the registration of a runner, you can specify the runner's tags, for example ruby, postgres, development.

tags allow you to run builds with runners that have the specified tags assigned to them:

job:
  tags:
    - ruby
    - postgres

The specification above, will make sure that job is built by a runner that has both ruby AND postgres tags defined.

when

when is used to implement jobs that are run in case of failure or despite the failure.

when can be set to one of the following values:

  1. on_success - execute build only when all builds from prior stages succeeded. This is the default.
  2. on_failure - execute build only when at least one build from prior stages failed.
  3. always - execute build despite the status of builds from prior stages.

For example:

stages:
- build
- cleanup_build
- test
- deploy
- cleanup

build_job:
  stage: build
  script:
  - make build

cleanup_build_job:
  stage: cleanup_build
  script:
  - cleanup build when failed
  when: on_failure

test_job:
  stage: test
  script:
  - make test

deploy_job:
  stage: deploy
  script:
  - make deploy

cleanup_job:
  stage: cleanup
  script:
  - cleanup after builds
  when: always

The above script will:

  1. Execute cleanup_build_job only when build_job fails
  2. Always execute cleanup_job as the last step in pipeline.

artifacts

Note: Introduced in GitLab Runner v0.7.0 for non-Windows platforms.

Note: Limited Windows support was added in GitLab Runner v.1.0.0. Currently not all executors are supported.

Note: Build artifacts are only collected for successful builds.

artifacts is used to specify list of files and directories which should be attached to build after success. Below are some examples.

Send all files in binaries and .config:

artifacts:
  paths:
  - binaries/
  - .config

Send all git untracked files:

artifacts:
  untracked: true

Send all git untracked files and files in binaries:

artifacts:
  untracked: true
  paths:
  - binaries/

You may want to create artifacts only for tagged releases to avoid filling the build server storage with temporary build artifacts.

Create artifacts only for tags (default-job will not create artifacts):

default-job:
  script:
    - mvn test -U
  except:
    - tags

release-job:
  script:
    - mvn package -U
  artifacts:
    paths:
    - target/*.war
  only:
    - tags

The artifacts will be sent to GitLab after a successful build and will be available for download in the GitLab UI.

cache

Note: Introduced in GitLab Runner v0.7.0.

cache is used to specify list of files and directories which should be cached between builds. Below are some examples:

Cache all files in binaries and .config:

rspec:
  script: test
  cache:
    paths:
    - binaries/
    - .config

Cache all git untracked files:

rspec:
  script: test
  cache:
    untracked: true

Cache all git untracked files and files in binaries:

rspec:
  script: test
  cache:
    untracked: true
    paths:
    - binaries/

Locally defined cache overwrites globally defined options. This will cache only binaries/:

cache:
  paths:
  - my/files

rspec:
  script: test
  cache:
    paths:
    - binaries/

The cache is provided on best effort basis, so don't expect that cache will be always present. For implementation details please check GitLab Runner.

Validate the .gitlab-ci.yml

Each instance of GitLab CI has an embedded debug tool called Lint. You can find the link under /ci/lint of your gitlab instance.

Skipping builds

If your commit message contains [ci skip], the commit will be created but the builds will be skipped.