• Validate the CI YAML configuration
  • YAML expansion
• Validate a CI YAML configuration with a namespace
• Validate a project’s CI configuration
• Use jq to create and process YAML & JSON payloads
  • Escape YAML for JSON encoding
  • Parse a CI Lint response

CI Lint API

Validate the CI YAML configuration

Checks if CI/CD YAML configuration is valid. This endpoint validates basic CI/CD configuration syntax. It doesn’t have any namespace-specific context.

Access to this endpoint does not require authentication when the instance allows new sign ups and:

• Does not have an allowlist or denylist.
• Does not require administrator approval for new sign ups.
• Does not have additional sign up restrictions.

Otherwise, authentication is required.

POST /ci/lint

curl --header "Content-Type: application/json" --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/ci/lint" --data '{"content": "{ \"image\": \"ruby:2.6\", \"services\": [\"postgres\"], \"before_script\": [\"bundle install\", \"bundle exec rake db:create\"], \"variables\": {\"DB_NAME\": \"postgres\"}, \"types\": [\"test\", \"deploy\", \"notify\"], \"rspec\": { \"script\": \"rake spec\", \"tags\": [\"ruby\", \"postgres\"], \"only\": [\"branches\"]}}"}'

Be sure to paste the exact contents of your GitLab CI/CD YAML configuration because YAML is very sensitive about indentation and spacing.

Example responses:

• Valid content:

  {
    "status": "valid",
    "errors": [],
    "warnings": []
  }
  

• Valid content with warnings:

  {
    "status": "valid",
    "errors": [],
    "warnings": ["jobs:job may allow multiple pipelines to run for a single action due to
    `rules:when` clause with no `workflow:rules` - read more:
    https://docs.gitlab.com/ee/ci/troubleshooting.html#pipeline-warnings"]
  }
  

• Invalid content:

  {
    "status": "invalid",
    "errors": [
      "variables config should be a hash of key value pairs"
    ],
    "warnings": []
  }
  

• Without the content attribute:

  {
    "error": "content is missing"
  }
  

YAML expansion

The CI lint returns an expanded version of the configuration. The expansion does not work for CI configuration added with include: local, and the extends: keyword is not fully supported.

Example contents of a .gitlab-ci.yml passed to the CI Lint API with include_merged_yaml and include_jobs set as true:

include:
  remote: 'https://example.com/remote.yaml'

test:
  stage: test
  script:
    - echo 1

Example contents of https://example.com/remote.yaml:

another_test:
  stage: test
  script:
    - echo 2

Example response:

{
  "status": "valid",
  "errors": [],
  "merged_yaml": "---\n:another_test:\n  :stage: test\n  :script: echo 2\n:test:\n  :stage: test\n  :script: echo 1\n",
  "jobs": [
    {
      "name":"test",
      "stage":"test",
      "before_script":[],
      "script":["echo 1"],
      "after_script":[],
      "tag_list":[],
      "environment":null,
      "when":"on_success",
      "allow_failure":false,
      "only":{
        "refs":["branches","tags"]
      },
      "except":null
    },
    {
      "name":"another_test",
      "stage":"test",
      "before_script":[],
      "script":["echo 2"],
      "after_script":[],
      "tag_list":[],
      "environment":null,
      "when":"on_success",
      "allow_failure":false,
      "only":{
        "refs":["branches","tags"]
      },
      "except":null
    }
  ]
}

Validate a CI YAML configuration with a namespace

Checks if CI/CD YAML configuration is valid. This endpoint has namespace specific context.

POST /projects/:id/ci/lint

Example request:

curl --header "Content-Type: application/json" "https://gitlab.example.com/api/v4/projects/:id/ci/lint" --data '{"content": "{ \"image\": \"ruby:2.6\", \"services\": [\"postgres\"], \"before_script\": [\"bundle install\", \"bundle exec rake db:create\"], \"variables\": {\"DB_NAME\": \"postgres\"}, \"types\": [\"test\", \"deploy\", \"notify\"], \"rspec\": { \"script\": \"rake spec\", \"tags\": [\"ruby\", \"postgres\"], \"only\": [\"branches\"]}}"}'

Example responses:

• Valid configuration:

  {
    "valid": true,
    "merged_yaml": "---\n:test_job:\n  :script: echo 1\n",
    "errors": [],
    "warnings": []
  }
  

• Invalid configuration:

  {
    "valid": false,
    "merged_yaml": "---\n:test_job:\n  :script: echo 1\n",
    "errors": [
      "jobs config should contain at least one visible job"
    ],
    "warnings": []
  }
  

Validate a project’s CI configuration

Checks if a project’s latest (HEAD of the project’s default branch) .gitlab-ci.yml configuration is valid. This endpoint uses all namespace specific data available, including variables and local includes.

GET /projects/:id/ci/lint

Example request:

curl "https://gitlab.example.com/api/v4/projects/:id/ci/lint"

Example responses:

• Valid configuration:

{
  "valid": true,
  "merged_yaml": "---\n:test_job:\n  :script: echo 1\n",
  "errors": [],
  "warnings": []
}

• Invalid configuration:

{
  "valid": false,
  "merged_yaml": "---\n:test_job:\n  :script: echo 1\n",
  "errors": [
    "jobs config should contain at least one visible job"
  ],
  "warnings": []
}

Use jq to create and process YAML & JSON payloads

To POST a YAML configuration to the CI Lint endpoint, it must be properly escaped and JSON encoded. You can use jq and curl to escape and upload YAML to the GitLab API.

Escape YAML for JSON encoding

To escape quotes and encode your YAML in a format suitable for embedding within a JSON payload, you can use jq. For example, create a file named example-gitlab-ci.yml:

.api_test:
  rules:
    - if: $CI_PIPELINE_SOURCE=="merge_request_event"
      changes:
        - src/api/*
deploy:
  extends:
    - .api_test
  rules:
    - when: manual
      allow_failure: true
  script:
    - echo "hello world"

Next, use jq to escape and encode the YAML file into JSON:

jq --raw-input --slurp < example-gitlab-ci.yml

To escape and encode an input YAML file (example-gitlab-ci.yml), and POST it to the GitLab API using curl and jq in a one-line command:

jq --null-input --arg yaml "$(<example-gitlab-ci.yml)" '.content=$yaml' \
| curl "https://gitlab.com/api/v4/ci/lint?include_merged_yaml=true" \
--header 'Content-Type: application/json' \
--data @-

Parse a CI Lint response

To reformat the CI Lint response, you can use jq. You can pipe the CI Lint response to jq, or store the API response as a text file and provide it as an argument:

jq --raw-output '.merged_yaml | fromjson' <your_input_here>

Example input:

{"status":"valid","errors":[],"merged_yaml":"---\n:.api_test:\n  :rules:\n  - :if: $CI_PIPELINE_SOURCE==\"merge_request_event\"\n    :changes:\n    - src/api/*\n:deploy:\n  :rules:\n  - :when: manual\n    :allow_failure: true\n  :extends:\n  - \".api_test\"\n  :script:\n  - echo \"hello world\"\n"}

Becomes:

:.api_test:
  :rules:
  - :if: $CI_PIPELINE_SOURCE=="merge_request_event"
    :changes:
    - src/api/*
:deploy:
  :rules:
  - :when: manual
    :allow_failure: true
  :extends:
  - ".api_test"
  :script:
  - echo "hello world"

With a one-line command, you can:

1. Escape the YAML
2. Encode it in JSON
3. POST it to the API with curl
4. Format the response

jq --null-input --arg yaml "$(<example-gitlab-ci.yml)" '.content=$yaml' \
| curl "https://gitlab.com/api/v4/ci/lint?include_merged_yaml=true" \
--header 'Content-Type: application/json' --data @- \
| jq --raw-output '.merged_yaml | fromjson'