catalog/CONTRIBUTING.md

Contributing to the catalog repo

Thank you for your interest in contributing!

This doc is about how to contribute to this repo specifically. For how to contribute to tektoncd projects in general, see the overview in our README and the individual CONTRIBUTING.md files in each respective project.

All contributors must comply with the code of conduct.

PRs are welcome, and will follow the tektoncd pull request process.

How to Contribute a Task or Pipeline

The Catalog repository is intended to serve as a location where users can find Tasks and Pipelines that are maintained, useful and follow established best practices.

The process for contributing looks like this:

1. Fork this repository, develop and test your Tasks.
2. Create a new folder for your Task(s)
3. Ensure your Task
   1. Follows the guidelines
   2. Meets the technical requirements
   3. Includes OWNERS
4. Submit a pull request.

Guidelines

When reviewing PRs that add new Tasks or Pipelines, maintainers will follow the following guidelines:

• Submissions should be useful in real-world applications. While this repository is meant to be educational, its primary goal is to serve as a place users can find, share and discover useful components. This is not a samples repo to showcase Tekton features, this is a collection
• Submissions should follow established best practices. Tekton is still young so this is going to be a shifting goalpost, but here are some examples:
  • Tasks should expose parameters and declare input/output resources, and document them.
  • Submissions should be as portable as possible. They should not be hardcoded to specific repositories, clusters, environments etc.
  • Images should either be pinned by digest or point to tags with documented maintenance policies. The goal here is to make it so that submissions keep working.
• Submissions should be well-documented.
• Coming Soon Submissions should be testable, and come with the required tests.

If you have an idea for a new submission, feel free to open an issue to discuss the idea with the catalog maintainers and community. Once you are ready to write your submission, please open a PR with the code, documentation and tests and a maintainer will review it.

Over time we hope to create a scalable ownership system where community members can be responsible for maintaining their own submissions, but we are not there yet.

Technical requirements

• Must pass the Task validation (aka kubectl create -f task.yaml should succeed)
• Images should be published and maintained on an public image registry (gcr.io, docker.io, quay.io, …). A bonus if those images are auto-built.
• Images should not have any major security vulnerabilities
• Should follow Kubernetes best practices
• Provide as many default paramater values as possible
• Provide end to end tests
• (Nice to have) : provide versions with and without PipelineResource

End to end Testing

There is two type of e2e tests launched on CI.

The first one would just apply the yaml files making sure they don't have any syntax issues. Pretty simple one, it just basically check the syntax.

The second one would do some proper functional testing, making sure the task actually ran properly.

The way the functional tests works is that if you have a directory called tests/ inside the task, it would start creating a random Namespace, apply the task and then every yaml files that you have in that tests/ directory.

Note that the test runner for the integration tests will only test the tasks that has been added or modified in the submitted PR and will not run any other tests that hasn't been changed unless the environment variable TEST_RUN_ALL_TESTS has been set.

Usually in these other yaml files you would have a yaml file for the test resources (PipelineResource) and a yaml files to run the tasks (TaskRun or PipelineRun).

Sometime you may need to be able to launch some scripts before applying the tested task or the other yaml files. Some may pre-setup something on the Namespace or have to do something externally or sometimes you may even want to do some manipulation of the main Task.

For example on the image builders tasks like kaniko or jib we want to upload the tasks to a registry to make sure it is actually built properly. To do so we manipulate with a python script the Task (something we don't want for everyone but only for the tests) to add a registry as a Sidecar and make sure that the TaskRun set the parameters to upload there. Simple and straightforward no need to upload to an external image registry provider having to setup the tokens and deals with the side effects...

There is two different scripts that are checked if present in the scripts, those scripts actually sourced via the source bash script, so you can output some environment variables to it that would be applied :

1. pre-apply-task-hook.sh: Script to run before applying the task
2. pre-apply-taskrun-hook.sh: Script to run before applying the taskruns or other yaml files.

We have some helper functions you can use from your hook scripts :

• add_sidecar_registry: This will add a registry as a sidecar to allow the builder tasks to upload image directly to this sidecar registry instead of having to rely on external registries.
• add_task: Install a task into the testing namespace, the first argument is the name of the task, the second argument is the version of the task. If the version is equal to latest it will install the latest version of the task.

What can you run from those scripts is whatever defined in the test-runner image, if you need to have another binary available feel free to make a PR to this Dockerfile :

https://github.com/tektoncd/plumbing/blob/master/tekton/images/test-runner/Dockerfile

An helper script called run-test.sh is provider in the test directory to help the developer running the test locally. Just specify the task name and the version as the first and the second argument i.e:

./test/run-test.sh git-clone 0.1

and it will use your kubernetes to run the test and show you the outputs as done in the CI.

End to end Testing for external services

Some tasks need to be able to access some external REST api services.

There are two approaches for testing external services, the first one if you can is to spin up a deployment of the service tests and exposed as a kubernetes service and the second one is an http rest api reflector for task that connect to rest apis endpoint that cannot be available as a deployment (i.e: Saas services like github)

For the first approach, you can take the trigger-jenkins-build test as an example.

You will want to modify the pre-apply-task-hook.sh script to create the deployment and make it available to your test pipelinerun.

Here is a rundown of the steps we are doing in trigger-jenkins-build/pre-apply-task-hook.sh script :

• Create a deployment with the jenkins image
• Wait until the deployment has completed.
• expose the deployment as a service, which would then be easily available for other pods in the namespace.
• Do some shenanigans inside the jenkins pod so we can grab the jenkins apikey and create a new jenkins job.
• create a secret with the apikey, username and other stuff.

The test pipelinerun for the trigger-jenkins-build/ will then points to http://jenkins:8080 which it the service URL where our just deployed jenkins is exposed and use the secrets credentials from the just created secret in the pre-apply-task-hook.sh script.

For those other services where you can't spin up a new deployment of the service easily, the test runner support the "Go Rest api test" project. The Go rest api test project is a simple service that replies back to http requests according to rules.

As an example see the github-add-comment task. For this task to be tested we need to be able to "fake" the Github REST api calls. To be able to do so, we are adding a go-rest-api-test rule inside the testing repository, the rule looks like this :

---
headers:
  method: POST
  path: /repos/{repo:[^/]+/[^/]+}/issues/{issue:[0-9]+}/comments
response:
  status: 200
  output: '{"status": 200}'
  content-type: text/json

The rules is saying that for every POST requests going to this url :

/repos/${ORG}/${REPO}/issues/${issues}/comments

we will reply by a 200 status and output {"status": 200}

The Pipelinerun test for the github-add-comment task overrides the github host url in its param to point to localhost:8080 :

    - name: GITHUB_HOST_URL
      value: http://localhost:8080

In the test runner if we find a directory called task/${task}/${version}/tests/fixtures we automatically spin up the "go-rest-api-test" server as a sidecar container with the test's fixtures yaml as the config. It will be then available to the task locally to this URL http://localhost:8080.

The task runs against that service instead of the github servcer and the responder replies with the right calls, we know then that the task has been properly tested.

The only requirement to use the fixtures testing facility is to be have the task having the capability via a task parameter to override the URL.

The go-rest-api-test is a very simple service at the moment and may see other improvements in the future to support more robust testing.

Owning and Maintaining a Task

Individual tasks should maintained by one or more users of GitHub. When someone maintains a Task, they have the access to merge changes to that Task. To have merge access to a Task, someone needs to:

1. Be invited (and accept your invite) as a read-only collaborator on the tekton organization. If you need sponsors and have contributed to the chart, please reach out to the existing maintainers, or if you are having trouble connecting with them, please reach out to one of the main OWNERS of this repository.
2. an OWNERS file needs to be added in the Task folder. That OWNERS file should list the maintainers' GitHub login names for both the reviewers and approvers sections.

OWNERS

The top-level OWNERS file lists the Trusted Collaborators. The process to becoming an OWNER is the same as other Tekton projects.