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---
# Pipelines for the GitLab project
Pipelines for [`gitlab-org/gitlab`](https://gitlab.com/gitlab-org/gitlab) (as well as the `dev` instance's) is configured in the usual
We're striving to [dogfood](https://about.gitlab.com/handbook/engineering/development/principles/#dogfooding)
GitLab [CI/CD features and best-practices](../../ci/yaml/index.md)
as much as possible.
## Minimal test jobs before a merge request is approved
**To reduce the pipeline cost and shorten the job duration, before a merge request is approved, the pipeline will run a minimal set of RSpec & Jest tests that are related to the merge request changes.**
After a merge request has been approved, the pipeline would contain the full RSpec & Jest tests. This will ensure that all tests
have been run before a merge request is merged.
### Overview of the GitLab project test dependency
To understand how the minimal test jobs are executed, we need to understand the dependency between
GitLab code (frontend and backend) and the respective tests (Jest and RSpec).
This dependency can be visualized in the following diagram:
```mermaid
flowchart LR
subgraph frontend
fe["Frontend code"]--tested with-->jest
end
subgraph backend
be["Backend code"]--tested with-->rspec
end
be--generates-->fixtures["frontend fixtures"]
fixtures--used in-->jest
```
In summary:
- RSpec tests are dependent on the backend code.
- Jest tests are dependent on both frontend and backend code, the latter through the frontend fixtures.
### RSpec minimal jobs
#### Determining related RSpec test files in a merge request
To identify the minimal set of tests needed, we use the [`test_file_finder` gem](https://gitlab.com/gitlab-org/ci-cd/test_file_finder), with two strategies:
- dynamic mapping from test coverage tracing (generated via the [`Crystalball` gem](https://github.com/toptal/crystalball))
([see where it's used](https://gitlab.com/gitlab-org/gitlab/-/blob/47d507c93779675d73a05002e2ec9c3c467cd698/tooling/bin/find_tests#L15))
- static mapping maintained in the [`tests.yml` file](https://gitlab.com/gitlab-org/gitlab/-/blob/master/tests.yml) for special cases that cannot
be mapped via coverage tracing ([see where it's used](https://gitlab.com/gitlab-org/gitlab/-/blob/47d507c93779675d73a05002e2ec9c3c467cd698/tooling/bin/find_tests#L12))
The test mappings contain a map of each source files to a list of test files which is dependent of the source file.
In the `detect-tests` job, we use this mapping to identify the minimal tests needed for the current merge request.
Later on in [the `rspec fail-fast` job](#fail-fast-job-in-merge-request-pipelines), we run the minimal tests needed for the current merge request.
#### Exceptional cases
In addition, there are a few circumstances where we would always run the full RSpec tests:
- when the `pipeline:run-all-rspec` label is set on the merge request
- when the `pipeline:run-full-rspec` label is set on the merge request, this label is assigned by triage automation when the merge request is approved by any reviewer
- when the merge request is created by an automation (for example, Gitaly update or MR targeting a stable branch)
- when the merge request is created in a security mirror
- when any CI configuration file is changed (for example, `.gitlab-ci.yml` or `.gitlab/ci/**/*`)
### Jest minimal jobs
#### Determining related Jest test files in a merge request
To identify the minimal set of tests needed, we pass a list of all the changed files into `jest` using the [`--findRelatedTests`](https://jestjs.io/docs/cli#--findrelatedtests-spaceseparatedlistofsourcefiles) option.
In this mode, `jest` would resolve all the dependencies of related to the changed files, which include test files that have these files in the dependency chain.
#### Exceptional cases
In addition, there are a few circumstances where we would always run the full Jest tests:
- when the merge request is created by an automation (for example, Gitaly update or MR targeting a stable branch)
- when the merge request is created in a security mirror
- when any CI configuration file is changed (for example, `.gitlab-ci.yml` or `.gitlab/ci/**/*`)
- when any frontend "core" file is changed (for example, `package.json`, `yarn.lock`, `babel.config.js`, `jest.config.*.js`, `config/helpers/**/*.js`)
- when any vendored JavaScript file is changed (for example, `vendor/assets/javascripts/**/*`)
- when any backend file is changed ([see the patterns list for details](https://gitlab.com/gitlab-org/gitlab/-/blob/3616946936c1adbd9e754c1bd06f86ba670796d8/.gitlab/ci/rules.gitlab-ci.yml#L205-216))
### Fork pipelines
We run only the minimal RSpec & Jest jobs for fork pipelines, unless the `pipeline:run-all-rspec`
label is set on the MR. The goal is to reduce the CI/CD minutes consumed by fork pipelines.
See the [experiment issue](https://gitlab.com/gitlab-org/quality/team-tasks/-/issues/1170).
## Fail-fast job in merge request pipelines
To provide faster feedback when a merge request breaks existing tests, we are experimenting with a
fail-fast mechanism.
An `rspec fail-fast` job is added in parallel to all other `rspec` jobs in a merge
request pipeline. This job runs the tests that are directly related to the changes
in the merge request.
If any of these tests fail, the `rspec fail-fast` job fails, triggering a
`fail-pipeline-early` job to run. The `fail-pipeline-early` job:
- Cancels the currently running pipeline and all in-progress jobs.
- Sets pipeline to have status `failed`.
For example:
```mermaid
graph LR
subgraph "prepare stage";
A["detect-tests"]
end
subgraph "test stage";
B["jest"];
C["rspec migration"];
D["rspec unit"];
E["rspec integration"];
F["rspec system"];
G["rspec fail-fast"];
end
subgraph "post-test stage";
Z["fail-pipeline-early"];
end
A --"artifact: list of test files"--> G
G --"on failure"--> Z
```
The `rspec fail-fast` is a no-op if there are more than 10 test files related to the
merge request. This prevents `rspec fail-fast` duration from exceeding the average
`rspec` job duration and defeating its purpose.
This number can be overridden by setting a CI/CD variable named `RSPEC_FAIL_FAST_TEST_FILE_COUNT_THRESHOLD`.
## Faster feedback when reverting merge requests
When you need to revert a merge request, to get accelerated feedback, you can add the `~pipeline:revert` label to your merge request.
When this label is assigned, the following steps of the CI/CD pipeline are skipped:
- The `e2e:package-and-test` job.
- The `rspec:undercoverage` job.
- The entire [Review Apps process](../testing_guide/review_apps.md).
Apply the label to the merge request, and run a new pipeline for the MR.
## Test jobs
We have dedicated jobs for each [testing level](../testing_guide/testing_levels.md) and each job runs depending on the
changes made in your merge request.
If you want to force all the RSpec jobs to run regardless of your changes, you can add the `pipeline:run-all-rspec` label to the merge request.
WARNING:
Forcing all jobs on docs only related MRs would not have the prerequisite jobs and would lead to errors
### Test suite parallelization
Our current RSpec tests parallelization setup is as follows:
1. The `retrieve-tests-metadata` job in the `prepare` stage ensures we have a
`knapsack/report-master.json` file:
- The `knapsack/report-master.json` file is fetched from the latest `main` pipeline which runs `update-tests-metadata`
(for now it's the 2-hourly `maintenance` scheduled master pipeline), if it's not here we initialize the file with `{}`.
1. Each `[rspec|rspec-ee] [migration|unit|integration|system|geo] n m` job are run with
`knapsack rspec` and should have an evenly distributed share of tests:
- It works because the jobs have access to the `knapsack/report-master.json`
since the "artifacts from all previous stages are passed by default".
- if knapsack is doing its job, test files that are run should be listed under
`Report specs`, not under `Leftover specs`.
1. The `update-tests-metadata` job (which only runs on scheduled pipelines for
[the canonical project](https://gitlab.com/gitlab-org/gitlab) takes all the
`knapsack/rspec*.json` files and merge them all together into a single
`knapsack/report-master.json` file that is saved as artifact.
After that, the next pipeline uses the up-to-date `knapsack/report-master.json` file.
### Flaky tests
#### Automatic skipping of flaky tests
Tests that are [known to be flaky](../testing_guide/flaky_tests.md#automatic-retries-and-flaky-tests-detection) are
skipped unless the `$SKIP_FLAKY_TESTS_AUTOMATICALLY` variable is set to `false` or if the `~"pipeline:run-flaky-tests"`
label is set on the MR.
See the [experiment issue](https://gitlab.com/gitlab-org/quality/team-tasks/-/issues/1069).
#### Automatic retry of failing tests in a separate process
Unless `$RETRY_FAILED_TESTS_IN_NEW_PROCESS` variable is set to `false` (`true` by default), RSpec tests that failed are automatically retried once in a separate
RSpec process. The goal is to get rid of most side-effects from previous tests that may lead to a subsequent test failure.
We keep track of retried tests in the `$RETRIED_TESTS_REPORT_FILE` file saved as artifact by the `rspec:flaky-tests-report` job.
See the [experiment issue](https://gitlab.com/gitlab-org/quality/team-tasks/-/issues/1148).
### Compatibility testing
By default, we run all tests with the versions that runs on GitLab.com.
Other versions (usually one back-compatible version, and one forward-compatible version) should be running in nightly scheduled pipelines.
Exceptions to this general guideline should be motivated and documented.
#### Single database testing
By default, all tests run with [multiple databases](../database/multiple_databases.md).
We also run tests with a single database in nightly scheduled pipelines, and in merge requests that touch database-related files.
If you want to force tests to run with a single database, you can add the `pipeline:run-single-db` label to the merge request.
### Monitoring
The GitLab test suite is [monitored](../performance.md#rspec-profiling) for the `main` branch, and any branch
that includes `rspec-profile` in their name.
### Logging
- Rails logging to `log/test.log` is disabled by default in CI
For now, CI will try to fetch the branch on the [GitLab JH mirror](https://gitlab.com/gitlab-org/gitlab-jh-mirrors/gitlab), so it might take some time for the new JH branch to propagate to the mirror.
After having the `as-if-jh/*` branch, `start-as-if-jh` job will trigger a pipeline
in the [validation project](https://gitlab.com/gitlab-org-sandbox/gitlab-jh-validation)
to run the cross-project downstream pipeline.
#### How the GitLab JH mirror project is set up
The [GitLab JH mirror](https://gitlab.com/gitlab-org/gitlab-jh-mirrors/gitlab) project is private and CI is disabled.
It's a pull mirror pulling from [GitLab JH](https://jihulab.com/gitlab-cn/gitlab),
mirroring all branches, overriding divergent refs, triggering no pipelines
when mirror is updated.
The pulling user is [`@gitlab-jh-bot`](https://gitlab.com/gitlab-jh-bot), who
is a maintainer in the project. The credentials can be found in the 1password
engineering vault.
No password is used from mirroring because GitLab JH is a public project.
#### How the GitLab JH validation project is set up
This [GitLab JH validation](https://gitlab.com/gitlab-org-sandbox/gitlab-jh-validation) project is public and CI is enabled, without any project variables.
It's a pull mirror pulling from [GitLab JH mirror](https://gitlab.com/gitlab-org/gitlab-jh-mirrors/gitlab),
mirroring only protected branches, `master` and `main-jh`, overriding
divergent refs, triggering no pipelines when mirror is updated.
The pulling user is [`@gitlab-jh-validation-bot`](https://gitlab.com/gitlab-jh-validation-bot), who is a maintainer in the project, and also a
The `rspec:undercoverage` job has [known bugs](https://gitlab.com/groups/gitlab-org/-/epics/8254)
that can cause false positive failures. You can test coverage locally to determine if it's
safe to apply `~"pipeline:skip-undercoverage"`. For example, using `<spec>` as the name of the
test causing the failure:
1. Run `SIMPLECOV=1 bundle exec rspec <spec>`.
1. Run `scripts/undercoverage`.
If these commands return `undercover: ✅ No coverage is missing in latest changes` then you can apply `~"pipeline:skip-undercoverage"` to bypass pipeline failures.
## Ruby versions testing
Our test suite runs against Ruby 2 in merge requests and default branch pipelines.
We also run our test suite against Ruby 3 on another 2-hourly scheduled pipelines, as GitLab.com will soon run on Ruby 3.
## PostgreSQL versions testing
Our test suite runs against PG12 as GitLab.com runs on PG12 and
[Omnibus defaults to PG12 for new installs and upgrades](../../administration/package_information/postgresql_versions.md).
We do run our test suite against PG11 and PG13 on nightly scheduled pipelines.
We also run our test suite against PG11 upon specific database library changes in MRs and `main` pipelines (with the `rspec db-library-code pg11` job).
| Merge requests | 12 (default version), 11 for DB library changes | 2.7 (default version) |
| `master` branch commits | 12 (default version), 11 for DB library changes | 2.7 (default version) |
| `maintenance` scheduled pipelines for the `master` branch (every even-numbered hour) | 12 (default version), 11 for DB library changes | 2.7 (default version) |
| `maintenance` scheduled pipelines for the `ruby3` branch (every odd-numbered hour), see below. | 12 (default version), 11 for DB library changes | 3.0 (coded in the branch) |
| `nightly` scheduled pipelines for the `master` branch | 12 (default version), 11, 13 | 2.7 (default version) |
The pipeline configuration for the scheduled pipeline testing Ruby 3 is
stored in the `ruby3-sync` branch. The pipeline updates the `ruby3` branch
with latest `master`, and then it triggers a regular branch pipeline for
`ruby3`. Any changes in `ruby3` are only for running the pipeline. It should
never be merged back to `master`. Any other Ruby 3 changes should go into
`master` directly, which should be compatible with Ruby 2.7.
Previously, `ruby3-sync` was using a project token stored in `RUBY3_SYNC_TOKEN`
(now backed up in `RUBY3_SYNC_TOKEN_NOT_USED`), however due to various
permissions issues, we ended up using an access token from `gitlab-bot` so now
`RUBY3_SYNC_TOKEN` is actually an access token from `gitlab-bot`.
### Long-term plan
We follow the [PostgreSQL versions shipped with Omnibus GitLab](../../administration/package_information/postgresql_versions.md):
Our test suite runs against Redis 6 as GitLab.com runs on Redis 6 and
[Omnibus defaults to Redis 6 for new installs and upgrades](https://gitlab.com/gitlab-org/omnibus-gitlab/-/blob/master/config/software/redis.rb).
We do run our test suite against Redis 5 on `nightly` scheduled pipelines, specifically when running backward-compatible and forward-compatible PostgreSQL jobs.
In general, pipelines for an MR fall into one of the following types (from shorter to longer), depending on the changes made in the MR:
- [Documentation pipeline](#documentation-pipeline): For MRs that touch documentation.
- [Backend pipeline](#backend-pipeline): For MRs that touch backend code.
- [Frontend pipeline](#frontend-pipeline): For MRs that touch frontend code.
- [End-to-end pipeline](#end-to-end-pipeline): For MRs that touch code in the `qa/` folder.
A "pipeline type" is an abstract term that mostly describes the "critical path" (for example, the chain of jobs for which the sum
of individual duration equals the pipeline's duration).
We use these "pipeline types" in [metrics dashboards](https://app.periscopedata.com/app/gitlab/858266/GitLab-Pipeline-Durations) to detect what types and jobs need to be optimized first.
An MR that touches multiple areas would be associated with the longest type applicable. For instance, an MR that touches backend
and frontend would fall into the "Frontend" pipeline type since this type takes longer to finish than the "Backend" pipeline type.
We use the [`rules:`](../../ci/yaml/index.md#rules) and [`needs:`](../../ci/yaml/index.md#needs) keywords extensively
to determine the jobs that need to be run in a pipeline. Note that an MR that includes multiple types of changes would
have a pipelines that include jobs from multiple types (for example, a combination of docs-only and code-only pipelines).
Following are graphs of the critical paths for each pipeline type. Jobs that aren't part of the critical path are omitted.
