As a service author I want to describe in a manifest which component steps are used to perform the Provision workflow

[ojhughes]

Using a manifest, describe which components (Spring Beans) are used to perform the Provision workflow as described: https://github.com/openservicebrokerapi/servicebroker/blob/master/spec.md#provisioning

The current design within App Broker is that each Workflow within OSB is decomposed into a set of actions eg. Create Service Instance, GetLastOperation. Each of these actions will be further decomposed into a pipeline, made up of many steps that are chained together. Each step is a FunctionalInterface. An example step would be generateCredential.

App Broker will provide a default for each type of step, such as a deployApp that deploys to CF. Users will be able to override each individual step by providing a Spring Bean that implements the appropriate interface. An alternative way of configuring what steps are used would be to specify the @Bean class type within a manifest. An example of what this might look like is:

actions:
  - create-service-instance
     steps:
     - CustomCredentialsGenerator
     - NoOpParameterValidator

The order of the steps is fixed, so ordering of the manifest doesn't matter. If any of the expected steps are omitted then a default will be used

[ojhughes]

Spring cloud gateway uses a similar concept to select which beans are used within it's manifest (albeit more complicated as allows parameters to be passed in) see https://github.com/spring-cloud/spring-cloud-gateway/blob/master/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/route/RouteDefinitionRouteLocator.java