Explore Gitlab CI components

Explore how we can set up an example CI component project and demonstrate the usage.

Intro

A CI/CD component is a reusable single pipeline configuration unit. Use components to create a small part of a larger pipeline, or even to compose a complete pipeline configuration. A component project is a GitLab project with a repository that hosts one or more components.

Purpose

What problems does it solve?

• Provide a description, sane defaults, and validation for the vars.
  • No more telling users to create vars in pipelines
• Ease of use since it is a drop-in to their CI config with include: component keyword
• Separation of concerns for software and infrastructure/CI code testing.
  • Efficient (time to dev and test). We can test the infrastructure code and the CI separately from the application code.
    • Avoid long wait times for the application code to compile and deploy when we want to test the infra code/CICD
• Standardized code.
  • Reduces code repetition
  • Eliminates scrolling 100's of lines, which leads to toil and missed changes
  • Speeds up dev.
• Create more dynamic jobs.
• Enforces good release practices - semantic versioning etc.
• Easily discoverable when published to a catalog
  • Central place for components. Easy to distribute.

Usage

Let's see how we can add a component to our project.

• A drop in with include: component keyword

include:
  - component: $CI_SERVER_FQDN/my-org/security-components/secret-detection@1.0.0
    inputs:
      stage: build

• $CI_SERVER_FQDN is a predefined variable for the fully qualified domain name (FQDN) matching the GitLab host. You can only reference components in the same GitLab instance as your project.
• my-org/security-components is the full path of the project containing the component.
• secret-detection is the component name that is defined as either a single file templates/secret-detection.yml or as a directory templates/secret-detection/ containing a template.yml.
• 1.0.0 is the version of the component.

Roadmap

The following tasks are identified to implement CICD components for rc/hpc-factory

Please refer to this issue for a roadmap. hpc-factory#301