Reimplement independently of SCAB

[gberche-orange]

Expected behavior

As an osb-cmdb contributor, in order to develop new feature and maintain osb-cmdb, I expect the osb-cmdb contributions to be productive

Observed behavior

• Effort required to handle Maintain stack, avoid SCAB fork (& changes lack automated test coverage) #6 is still important because

  • SCAB test strategy makes the test code base rigid and costly to evolve when introducing new features. This would sometimes require important refactoring to get new features in
  • The bar is too high w.r.t. our capacity in osb-cmdb
    • The expected test code coverage (unit test, component test with CF wiremocks, and acceptance test with live tests) is expensive
    • The static code analysis (pmd rules, checkstyle, compiler warnings) is strict
  • The osb-cmdb features don't seem to benefit much to SCAB to justify investment by SCAB maintainers

• Osb-cmdb contributions within SCAB code base are slowed down by

  • Overhead of maintaining/not breaking SCAB features
    • not used in osb-cmdb:
      • app brokering
      • multiple service brokering
      • future K8S support
      • pluggeable workflows
    • seldomly used: configureable brokering (SpacePerServiceOffering vs SpacePerServicePlan)
    • conflicting requirements:
      • service instance update optimization
  • Full non blocking reactor style which are
    • adding boiler plate code
    • sometimes restrictive
    • hard to learn and master
    • whose benefits does not yet seem to leveraged for osb-cmdb use cases:
      • no (or few) parallel processing
      • no backpressure

Possible alternatives

• Start from scratch

  • sc-osb
  • cf-java-client

• Simplify current scab-based osb-cmdb spike ?

  • Remove unused features
  • Remove extra layers / modules
  • Keep focused component / acceptance tests

When to schedule

• Now
• Before CF V3 API migration

[gberche-orange]

See design and prototype outline at https://gist.github.com/gberche-orange/69bb27be0bf07f7ada61c6b7342f9683 as an alternative to #6

[gberche-orange]

Implemented in v1.0.0 in commit 67f7cdd See further design notes at https://github.com/orange-cloudfoundry/osb-cmdb-spike/blob/v1.0.0/osb-cmdb/docs/Design-doc.md and implementation notes at https://github.com/orange-cloudfoundry/osb-cmdb-spike/blob/v1.0.0/osb-cmdb/docs/impl-notes/v10-redesign.md