Implement new plugin type to deal with EntryPoint

[guillaumelamirand]

:rainbow: Feature

As an developer I want to be able to propose new kind of entrypoints So that my client can propose new async api based on this new entrypoint

:sunrise_over_mountains: Additional information

• [x] This new plugin should be located inside apim mono repository, and it could be under gravitee-api-management / gravitee-apim-connectors / gravitee-apim-connectors-entrypoints > gravitee-apim-plugins/gravitee-apim-plugins-entrypoint
• [x] Existing gravitee-plugin-connector is a good starting point
• [x] Add this new module to sonar coverage; Update circle ci if required to build it.
• [x] New interfaces would be required to properly define an entrypoint . Those interfaces could be :
• EntryPointConnectorFactory
  • supportedApiType(): list the supported api types
  • supportedMode(): list the supported modes
  • ConnectorMode : REQUEST_RESPONSE, PUBLISH or SUBSCRIBE
  • create(): allow to create a connector instance
• EntryPointConnector
  • accept(): check if the current request is supported and return a complexity information to allow resolution priority. For example, http get has only one criteria (GET method) while SSE has 2 ( GET method and Content-type) so both could be the request but because SSE has more criteria it should be evaluated first.
  • handleRequest(): should be implemented while new request is made by a customer for example to transform incoming buffer into messages
  • handleResponse(): should be implemented to adapt client response for exemple to transform outgoing messages to buffer
• [x] Existing HandlerEntrypoint resolution should be renamed to HttpAcceptor.
• [x] Prepare the entry point connector resolver based on those new interfaces

:superhero: Acceptance criteria

• [x] I am able to implement new entrypoint plugin
• [x] Entrypoint configuration is validated using new plugin while creating/updating an api
• [x] I am able to list all available entrypoints and access to their configuration (same as /connectors)

[guillaumelamirand]

To be aligned with AM, we will use gravitee-apim-plugins/gravitee-apim-plugins-entrypoint as module names.

[guillaumelamirand]

EntryPointConnector#accept() has been split into two methods :

• matchesCriteria(): which should return the number of criteria to match the context (should always return the same value)
• matches(): which check if the given context matches the criterias

[guillaumelamirand]

Current status of the implementation:

• entrypoint plugin framework has been implemented
• entrypoint configuration while creating an new api is validating with the related entrypoint plugin available
• Api V4 deploiment has been implemented
• AsyncApiReactor has been implemented to be able to call an async api
• SSE Entrypoint has been implemented

Remaining work:

• unit tests could be added here and there #8291
• Update test sdk to be able to deploy api v4 #8286
• Update test sdk to handle entrypoint #8249
• Implement some integration test to validate new execution chain for async api

The PR opened are the following :

• apim PR: https://github.com/gravitee-io/gravitee-api-management/pull/2255
• api gateway PR: https://github.com/gravitee-io/gravitee-gateway-api/pull/130
• apikey PR: https://github.com/gravitee-io/gravitee-policy-apikey/pull/53
• keyless PR: https://github.com/gravitee-io/gravitee-policy-keyless/pull/31
• oauth2 PR: https://github.com/gravitee-io/gravitee-policy-oauth2/pull/57
• jwt PR: https://github.com/gravitee-io/gravitee-policy-jwt/pull/80

[LiliaEn]

Tested on default env v3.19.0 New SSE entrypoint is implemented and working as expected when creating/updating an async API.