Plural Observers in Continuous Deployment

Plural’s Observer framework implements the Observer Pattern, automatically watching external sources and triggering deployments based on detected changes. This eliminates the need for manual intervention when new versions of applications or dependencies are released.

Overview of Plural Observers

Plural’s Observer CRD (Observer resource) defines:

• What to watch: External targets like Git repositories, Helm registries, OCI registries, or Plural add-ons.
• How often to poll: Using a crontab schedule.
• What actions to perform: Launch a pipeline or open a pull request when changes are discovered.

This event-driven model integrates tightly with GitOps practices, ensuring deployments stay in sync with upstream artifacts dynamically and safely.

Scraping OCI Registries with Observers

Plural observers can scrape OCI-based repositories (e.g., container image repositories or Helm charts stored in OCI format). Here’s how this works:

• Target Type: OCI
• Configuration:
• URL: The address of the OCI repository to scrape.
• Optional authentication (BASIC, AWS, GCP, Bearer, Azure).
• Polling: Using a cron schedule, the observer lists tags or artifacts.
• Version Extraction: (Optional) A regex can be defined to match semantic versions (v1.2.3).

The observer will detect newly published tags or versions, compare them with previously seen ones, and if a new version is found, it will trigger actions based on the configuration.

Setup