add support for JetStream

[grimmjo]

This PR provides JetStream support for this module.

Jetstream is a built-in distributed persistence system on top of nats-core. It has additional features likes streams, clustering, replay policies, retention policies and limits, key/value stores.
Later they will also provide a object storage.

Some related links:

• https://docs.nats.io/nats-concepts/jetstream
• https://docs.nats.io/nats-concepts/jetstream/streams

Todos:

• rework nats configuration
• add jetstream configuration and factory
• add publishers (https://nats.io/blog/sync-async-publish-java-client/)
• add consumers (https://nats.io/blog/jetstream-java-client-03-consume/)
  • push based (https://nats.io/blog/jetstream-java-client-04-push-subscribe/)
  • pull based (https://nats.io/blog/jetstream-java-client-05-pull-subscribe/)
• documentation

This PR depends on micronaut-projects/micronaut-core#8424

[sonarqubecloud]

SonarCloud Quality Gate failed.   

1 Bug
0 Vulnerabilities
0 Security Hotspots
32 Code Smells

76.0% Coverage
0.9% Duplication

[sdelamo]

@grimmjo can you describe what this PR is trying to achieve? Provide as much context links as possible?

[timyates]

Cool, thanks! 😎

Looks like there's a breaking change in the configuration

You can no longer do (as shown in the documentation):

nats:
    addresses:
      - "nats://localhost:4222"
      - "nats://randomServer:4222"
    username: guest
    password: guest

You would need to change this to

nats:
    default:
        addresses:
          - "nats://localhost:4222"
          - "nats://randomServer:4222"
        username: guest
        password: guest

So this would need to be a major version release (4.0.0 at the time of writing this)

Also, this Optional looks like it may be accessed without a present check (Sonar is reporting it as a bug)

micronaut-nats/nats/src/main/java/io/micronaut/nats/jetstream/intercept/JetStreamConsumerAdvice.java

Lines 202 to 204 in f6c86f6

	PushSubscribeOptions options =
	buildConsumerConfiguration(streamName, durable,
	consumerConfigurationAnnotationValue.get());

Also there's quite a few code smells which will need looking at 🤔

https://sonarcloud.io/project/issues?id=micronaut-projects_micronaut-nats&pullRequest=254&resolved=false&types=CODE_SMELL

[grimmjo]

Hey @timyates,
thank you for your feedback 😃

The next version will be 4.0.0. I've already bumped the version to 4.0.0-SNAPSHOT.
There is still lots of things to do as for example a simple push consumer needs up to 3 annotations to work. I'm still simplifying the annotation api for this.

[sonarqubecloud]

Please retry analysis of this Pull-Request directly on SonarCloud.

[graemerocher]

Looks great! Just a few coments

[sonarqubecloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
11 Code Smells

75.4% Coverage
0.0% Duplication