Developer Guide

This developer guide aims to walk a new developer on how to setup up their environment to be able to contribute to this project.

Setting up development environment

To setup your system for development of the operator, follow the steps below:

  1. Clone the gitlab-operator repository into your GOPATH.

    git clone
    cd gitlab-operator
  2. Install asdf to manage runtime dependencies.

  3. Install runtime dependencies.

    cut -d' ' -f1 .tool-versions | xargs -i asdf plugin add {}
    asdf plugin add opm
    asdf install
  4. Run task from the root of the repository to see available commands.

    We use task from in place of make for this project. Here is why.

    Do not install task via brew install task. You will end up with Taskwarrior, which is a different package. Either user the asdf plugin from above, or follow installation instructions from

    See Taskfile.yaml for our task definitions.

Project structure

The GitLab Operator is built using the Operator SDK v1.0.0 and consequently uses the Kubebuilder v2 layout format. This is necessary to know since there was a change in project directory and some of the tooling used by operator SDK.

$ pwd
$ tree -dL 2 .
├── api
│   └── v1beta1
├── bundle
│   ├── manifests
│   ├── metadata
│   └── tests
├── config
│   ├── certmanager
│   ├── crd
│   ├── default
│   ├── deploy
│   ├── manager
│   ├── manifests
│   ├── prometheus
│   ├── rbac
│   ├── samples
│   ├── scorecard
|   ├── test
│   └── webhook
├── controllers
│   ├── backup
│   ├── gitlab
│   ├── helpers
│   ├── runner
│   ├── settings
│   ├── testdata
│   └── utils
├── doc
├── hack
│   └── assets
├── helm
│   └── testdata
└── scripts
    └── manifests
  • The controllers directory contains the controller implementations for the GitLab and GitLab Backup controllers.
  • The api directory contains the API resource definitions for the GitLab and GLBackup resources owned by the operator. The API definitions are grouped by their API version. The *_types.go file inside api/<api_version> contains spec definitions and markers used to generate the custom resource definitions and Cluster Service Version file used by OLM.
  • The config/samples directory contains an example manifest for the GitLab custom resource.
  • The config/test directory contains a parametrized GitLab definition used for running integration tests.

    An example is shown below:

    // +kubebuilder:rbac:groups=core,resources=configmaps,verbs=get;list;watch;create;update;patch;delete

    The contents of config/rbac/custom were created manually and is not affected by the RBAC markers.

    Most of the other contents of the config directory are automatically generated but could be modified using kustomize.

  • The hack/assets path contains resources that would need to be pushed inside the operator image when the container image is being built. This is where release files would go.

Deploying the Operator

For instructions on deploying the operator, see the installation docs.


There have been a couple of functions added to controllers/gitlab/template_test.go to assist in the development of features and the writing of tests.

  • dumpTemplate(template)
  • dumpTemplateToFile(template, filename)
  • dumpHelmValues(values)
  • dumpHelmValuesToFile(values, filename)

The dumpTemplate() function will take the template object from the GitLab adapter and return the rendered YAML of the Helm chart as a string. Since the Go test framework will absorb anything written to stdout, the dumpTemplateToFile() will write the YAML to a file for inspection. It is important to note that if just a filename is provided that the file will be written to the subdirectory where the test file resides rather than the directory where the tests were initiated from. An absolute file path is necessary if one desires the file to be written where the tests are initiated from.

Similarly the dumpHelmValues() will return the YAML representation of the Helm values as string. This is can be used to verify that the intended values are set at the beginning of any tests. The dumpHelmValues() function is used to write the YAML to a file for inspection and the filename argument has the same limitations as dumpTemplateToFile().