Create a GitLab repository that will serve as a how-to guide, and will contain:

• a README file with an overview of files in the repository and basic instructions on how to use them
• Blubber and GitLab CI configuration files with configuration of common CI elements for different projects and with comments explaining the configuration options in use
• Application code to test the configuration files

Use cases to consider:

• basic GitLab CI tests
• building container images using Dockerfiles and Blubber, and pushing them to different registries
• generating build artifacts, for example a Debian package, and pushing these artifacts to centralized repositories (for example an apt repository)
• running extra services necessary for pipeline jobs, for example a database used in tests (implemented in the end-to-end test stage)

Other considerations:

• use these configuration files in custom GitLab templates?
• ensure code and configuration files in this repository are tested automatically

Summary

(largely copied from this comment)

The repository is available on GitLab: https://gitlab.wikimedia.org/repos/technical-documentation/deployment-pipeline-sandbox

The repository contains:

• A README file with instructions for testing Blubber variants locally
• Five examples of web applications with the same functionality (display a plain text response which includes a random number - changed on every reload).
  • Languages used: Java, NodeJS, PHP, Python, and Rust
  • Each application has tests for its functionality
  • Each application uses standard and popular (to my knowledge) build mechanisms, libraries, and tools for the given language.
• Separate Blubber variants for building, testing, and running these applications (in .pipeline/blubber.yaml)
• GitLab CI job configurations for unit tests and end-to-end tests (in .gitlab-ci.yml)

Different variants and configurations showcase:

• how to use different builder configurations
• how to use Blubber and GitLab CI with different project directory structures (the NodeJS application uses a different configuration from the rest)
• how to use images from the Wikimedia registry (all applications) and from Docker Hub (Java and Rust applications)
• how to use a multi-stage image and transfer build artifacts between image stages (Rust application)
• how to run an application as a service in GitLab CI
• how to specify stages and job dependencies in GitLab CI
• how to use Kokkuri in your project

Content in the repository is automatically tested on merge/commit. Tests also run periodically, once a month.

Merge requests and comments welcome!