Knative

With the changes in the design of the Knative connector, this document is currently temporarily outdated.

Prerequisite

Create Knative Source and Sink

We use the cloudevents-player Knative service as an example. If you do not know how to create cloudevents-player Knative service as source and sink, please follow the steps in this link.

Set up EventMesh Configuration

• Add the following lines to eventmesh-starter/build.gradle file. ``` plugins { id ‘application’ }

application { mainClass = project.hasProperty(“mainClass”) ? project.getProperty(“mainClass”) : ‘org.apache.eventmesh.starter.StartUp’ applicationDefaultJvmArgs = [ ‘-Dlog4j.configurationFile=../eventmesh-runtime/conf/log4j2.xml’, ‘-Deventmesh.log.home=../eventmesh-runtime/logs’, ‘-Deventmesh.home=../eventmesh-runtime’, ‘-DconfPath=../eventmesh-runtime/conf’ ] }

dependencies { implementation project(“:eventmesh-connector-plugin:eventmesh-connector-knative”) implementation project(“:eventmesh-runtime”) }

- Add the following lines to [eventmesh-examples/build.gradle](https://github.com/apache/eventmesh/blob/master/eventmesh-examples/build.gradle) file.

plugins { id ‘application’ }

application { mainClass = project.hasProperty(“mainClass”) ? project.getProperty(“mainClass”) : ‘NULL’ }

- Set `eventMesh.connector.plugin.type=knative` in [eventmesh-runtime/conf/eventmesh.properties](https://github.com/apache/eventmesh/blob/master/eventmesh-runtime/conf/eventmesh.properties) file.
## Demo
### Publish an Event Message from Knative and Subscribe from EventMesh
#### Step 1: Start an EventMesh Runtime Server
```bash
$ cd eventmesh-starter
$ ../gradlew -PmainClass=org.apache.eventmesh.starter.StartUp run

Step 2: Publish an Event Message from Knative

$ curl -i http://cloudevents-player.default.127.0.0.1.sslip.io -H "Content-Type: application/json" -H "Ce-Id: 123456789" -H "Ce-Specversion: 1.0" -H "Ce-Type: some-type" -H "Ce-Source: command-line" -d '{"msg":"Hello CloudEvents!"}'

Step 3: Subscribe from an EventMesh

• Set public static final String EVENTMESH_HTTP_ASYNC_TEST_TOPIC = "messages"; in ExampleConstants.java file.

  $ cd eventmesh-examples
  $ ../gradlew -PmainClass=org.apache.eventmesh.http.demo.sub.SpringBootDemoApplication run

Expected Result

The following message with data field as Hello CloudEvents! will be printed on the console of EventMesh server.

2022-09-05 16:37:58,237 INFO  [eventMesh-clientManage-] DefaultConsumer(DefaultConsumer.java:60) - \
[{"event":{"attributes":{"datacontenttype":"application/json","id":"123456789","mediaType":"application/json",\
"source":"command-line","specversion":"1.0","type":"some-type"},"data":{"msg":"Hello CloudEvents!"},"extensions":{}},\
"id":"123456789","receivedAt":"2022-09-05T10:37:49.537658+02:00[Europe/Madrid]","type":"RECEIVED"}]

Publish an Event Message from EventMesh and Subscribe from Knative

Step 1: Start an EventMesh Runtime Server

$ cd eventmesh-starter
$ ../gradlew -PmainClass=org.apache.eventmesh.starter.StartUp run

Step 2: Publish an Event Message from EventMesh

We use a test program to demo this function.

$ cd eventmesh-connector-plugin/eventmesh-connector-knative
$ ../../gradlew clean test --tests KnativeProducerImplTest.testPublish

Step 3: Subscribe from Knative

$ curl http://cloudevents-player.default.127.0.0.1.sslip.io/messages

Expected Result

The following message with data field as Hello Knative from EventMesh! will be printed on the console of EventMesh server.

2022-09-05 16:52:41,633 INFO  [eventMesh-clientManage-] DefaultConsumer(DefaultConsumer.java:60) - \
[{"event":{"attributes":{"datacontenttype":"application/json","id":"1234","mediaType":"application/json",\
"source":"java-client","specversion":"1.0","type":"some-type"},"data":{"msg":["Hello Knative from EventMesh!"]},"extensions":{}},"id":"1234","receivedAt":"2022-09-05T10:52:32.999273+02:00[Europe/Madrid]","type":"RECEIVED"}]