[Enhancement] Slack intermediate catch event breaks on event subscription

[igpetrov]

Describe the issue

Intermediate catch event fails on the first request (challenge echo) because the proposed Correlation key (payload) field, suggested by the doc as request.body.event.text is never present but looks like {"token":"XXX","challenge":"YYY","type":"url_verification"} thus failing with 500.

While this is expected behaviour, 500 is not an option an degrades overall user experience when building an element template with Slack intermediate connector.

As a workaround suggested: if request.body.event = null then "" else request.body.event.text instead of request.body.event.text at least until we find a better approach.

Steps to Reproduce

1. Fill element template as per screenshot.
2. Deploy and start
3. Go to api.slack.com -> event subscriptions
4. Set an endpoint for events the one you obtained from BPMN
5. Get a lovely stack trace

io.camunda.connector.api.error.ConnectorInputException: io.camunda.connector.feel.FeelEngineWrapperException: Failed to evaluate expression '=request.body.event.text' in context 'WebhookTriggerResultContext[request=MappedHttpRequest[body={token=7w09PLZYUTFowXae6D63cCAz, challenge=hIIgdmJlDg8TNBjGJNgWD3hF7VF3zzyWeFJfAmaYEboTey1uHzjP, type=url_verification}, headers={host=localhost:8080, user-agent=curl/7.88.1, accept=*/*, content-type=application/json, x-slack-request-timestamp=1691588067, x-slack-signature=v0=5191aa1a466c86a1367a173c191873be19a442728047ea198c67dc97bd6ab84e, content-length=129}, params={}], connectorData={}]'. Reason: failed to evaluate expression 'request.body.event.text': context contains no entry with key 'event'
	at io.camunda.connector.runtime.core.inbound.correlation.InboundCorrelationHandler.extractCorrelationKey(InboundCorrelationHandler.java:161)
	at io.camunda.connector.runtime.core.inbound.correlation.InboundCorrelationHandler.triggerMessage(InboundCorrelationHandler.java:110)
	at io.camunda.connector.runtime.core.inbound.correlation.InboundCorrelationHandler.correlate(InboundCorrelationHandler.java:61)
	at io.camunda.connector.runtime.inbound.lifecycle.MeteredInboundCorrelationHandler.correlate(MeteredInboundCorrelationHandler.java:54)
	at io.camunda.connector.runtime.core.inbound.InboundConnectorContextImpl.correlate(InboundConnectorContextImpl.java:67)
	at io.camunda.connector.runtime.inbound.webhook.InboundWebhookRestController.processWebhook(InboundWebhookRestController.java:95)
	at io.camunda.connector.runtime.inbound.webhook.InboundWebhookRestController.lambda$inbound$0(InboundWebhookRestController.java:83)
	at java.base/java.util.Optional.map(Optional.java:260)
	at io.camunda.connector.runtime.inbound.webhook.InboundWebhookRestController.inbound(InboundWebhookRestController.java:78)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:118)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:884)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1081)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:974)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1011)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:914)
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:590)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:885)
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:658)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:205)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)
	at org.springframework.web.filter.ServerHttpObservationFilter.doFilterInternal(ServerHttpObservationFilter.java:109)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:166)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:115)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:391)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:894)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1740)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: io.camunda.connector.feel.FeelEngineWrapperException: Failed to evaluate expression '=request.body.event.text' in context 'WebhookTriggerResultContext[request=MappedHttpRequest[body={token=7w09PLZYUTFowXae6D63cCAz, challenge=hIIgdmJlDg8TNBjGJNgWD3hF7VF3zzyWeFJfAmaYEboTey1uHzjP, type=url_verification}, headers={host=localhost:8080, user-agent=curl/7.88.1, accept=*/*, content-type=application/json, x-slack-request-timestamp=1691588067, x-slack-signature=v0=5191aa1a466c86a1367a173c191873be19a442728047ea198c67dc97bd6ab84e, content-length=129}, params={}], connectorData={}]'. Reason: failed to evaluate expression 'request.body.event.text': context contains no entry with key 'event'
	at io.camunda.connector.feel.FeelEngineWrapper.evaluate(FeelEngineWrapper.java:115)
	at io.camunda.connector.feel.FeelEngineWrapper.evaluate(FeelEngineWrapper.java:120)
	at io.camunda.connector.runtime.core.inbound.correlation.InboundCorrelationHandler.extractCorrelationKey(InboundCorrelationHandler.java:159)
	... 62 common frames omitted
Caused by: java.lang.RuntimeException: failed to evaluate expression 'request.body.event.text': context contains no entry with key 'event'
	at io.camunda.connector.feel.FeelEngineWrapper.evaluateInternal(FeelEngineWrapper.java:154)
	at io.camunda.connector.feel.FeelEngineWrapper.evaluate(FeelEngineWrapper.java:113)
	... 64 common frames omitted

Suggested fix

• Perform implicit checks for authentication / challenge validation, or
• Note this in docs, or
• Prefill the Correlation key (payload) field with safe values, or
• Combination of these.

Environment

• All

[bastiankoerber]

need to be discussed in Architecture discussion. @igpetrov will share his thoughts in the architecture sync

[igpetrov]

With the 8.3.0 release it is throwing a new error:

InboundConnectorDefinitionImpl{correlationPoint=MessageCorrelationPoint[messageName=7db62ede-e85c-48cf-ad58-493bdc1fb21b, correlationKeyExpression==if request.body.event = null then "" else request.body.event.text, messageIdExpression=null], bpmnProcessId='Process_1gcw0hi', version=9, processDefinitionKey=2251799813686572, elementId='Event_1numar1, tenantId='null'} failed with exception
io.camunda.connector.api.error.ConnectorException: java.lang.NullPointerException
	at io.camunda.connector.runtime.core.inbound.correlation.InboundCorrelationHandler.triggerMessage(InboundCorrelationHandler.java:232)
	at io.camunda.connector.runtime.core.inbound.correlation.InboundCorrelationHandler.correlate(InboundCorrelationHandler.java:68)
	at io.camunda.connector.runtime.core.inbound.correlation.InboundCorrelationHandler.correlate(InboundCorrelationHandler.java:56)
	at io.camunda.connector.runtime.inbound.lifecycle.MeteredInboundCorrelationHandler.correlate(MeteredInboundCorrelationHandler.java:54)
	at io.camunda.connector.runtime.core.inbound.InboundConnectorContextImpl.correlate(InboundConnectorContextImpl.java:66)
	at io.camunda.connector.runtime.inbound.webhook.InboundWebhookRestController.processWebhook(InboundWebhookRestController.java:95)
	at io.camunda.connector.runtime.inbound.webhook.InboundWebhookRestController.lambda$inbound$0(InboundWebhookRestController.java:83)
	at java.base/java.util.Optional.map(Unknown Source)
	at io.camunda.connector.runtime.inbound.webhook.InboundWebhookRestController.inbound(InboundWebhookRestController.java:78)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:118)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:884)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleIntern… [message truncated due to size] 

Investigating

[igpetrov]

Fixed in 8.3.1