Prototypes

[matthewpereira]

TLDR

• Creating a flexible new abstraction to better support reusable tasks allows application operators and application developers work with reusable, versioned pipeline elements in a way that can simplify their pipeline configuration, and allows them to perform common tasks in a more intuitive way.

Problem

• Concourse's resource primitive is a powerful and flexible concept for managing with versioned pipeline inputs and outputs, but there are many cases where this breaks down in practical use.
  • For example, pull request resource types represent each pull request as a version so that you can use Concourse to run tests for all your PRs. This means that your build history might be pointing at different PR in each build, or you might get into weird situations because version: every allows versions to be skipped when used with passed: constraints
  • Build retriggering helps recreate builds for a specific PR, but only if it has already run and exists in the history. Otherwise you have to look up the right version in the git resource, pin, run, validate, and unpin to ensure that everything goes back to normal afterward.
• Tasks are more flexible, but require a lot more work and verbose boilerplate to configure and maintain. Verbosity means wasting time on typos and forgetting details.
  • Tasks can almost be packaged up and re-used as easily as resource types, but it would be helpful to have more advanced abilities on top of this functionality
• Ideally, we need something as versatile as tasks and as easy to use as resource types.

Use Cases

• Workflow/infrastructure automation
• Continuous Integration

Proposed Solution

• Creating a new abstraction (prototypes) would help make configuring and reusing pipelines a lot easier.

Outcomes

• Navigating the Concourse landscape becomes a lot easier: instead of using 'generalized resources' for spatial resources, notifications, and triggers, users would use 'prototypes' instead.

Current Status

• In Progress

References

concourse/rfcs#37
concourse/rfcs#38
#6540 - Add support for prototypes

See: Reinventing Resource Types