telegram-source seems to not emit proper cloud-events

[rhuss]

When using the telegram-source and connect it properly to telegram and a Knative event sink, when I send a text message via Telegram, I receive an error that indicates that an invalid cloud-event sink is sent to the sink:

Failed delivery for (MessageId: 0DC421EDD62EC02-0000000000000001 on ExchangeId: 0DC421EDD62EC02-0000000000000001). Exhausted after delivery attempt: 1 caught: org.apache.camel.CamelException: HTTP operation failed invoking http://broker-ingress.knative-eventing.svc.cluster.local/default/default with statusCode: 400, statusMessage: Bad Request

Message History (complete message history is disabled)
---------------------------------------------------------------------------------------------------------------------------------------
RouteId              ProcessorId          Processor                                                                        Elapsed (ms)
[source            ] [source            ] [from[telegram://bots?authorizationToken=xxxxxx]                               ] [         8]
	...
[route1            ] [to1               ] [knative:event?apiVersion=eventing.knative.dev%2Fv1&kind=Broker                ] [         0]

Stacktrace
---------------------------------------------------------------------------------------------------------------------------------------
: org.apache.camel.CamelException: HTTP operation failed invoking http://broker-ingress.knative-eventing.svc.cluster.local/default/default with statusCode: 400, statusMessage: Bad Request
	at org.apache.camel.component.knative.http.KnativeHttpProducer.lambda$process$0(KnativeHttpProducer.java:135)
	at io.vertx.ext.web.client.impl.HttpContext.handleDispatchResponse(HttpContext.java:371)
	at io.vertx.ext.web.client.impl.HttpContext.execute(HttpContext.java:358)
	at io.vertx.ext.web.client.impl.HttpContext.next(HttpContext.java:336)
	at io.vertx.ext.web.client.impl.HttpContext.fire(HttpContext.java:303)
	at io.vertx.ext.web.client.impl.HttpContext.dispatchResponse(HttpContext.java:265)
	at io.vertx.ext.web.client.impl.HttpContext.lambda$null$8(HttpContext.java:520)
	at io.vertx.core.impl.AbstractContext.dispatch(AbstractContext.java:96)
	at io.vertx.core.impl.AbstractContext.dispatch(AbstractContext.java:59)
	at io.vertx.core.impl.EventLoopContext.lambda$runOnContext$0(EventLoopContext.java:37)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:472)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:497)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:829)

and in the broker's log (that I used as sink):

{
  "level": "warn",
  "ts": "2021-09-15T09:17:11.321Z",
  "logger": "mt_broker_ingress",
  "caller": "ingress/ingress_handler.go:137",
  "msg": "failed to extract event from request",
  "commit": "0c41e6d",
  "error": "bad key, CloudEvents attribute names MUST consist of lower-case letters ('a' to 'z') or digits ('0' to '9') from the ASCII character set"
}

I'm using Camel-K 1.6.0 on Minikube

[heiko-braun]

@nicolaferraro FYI