Add support to specify partition key on EventHub output binding

[jeffhollan]

Today for C# functions if you send EventData type to the output binding you can define a system property for partition key which is honored when sending the message. Today the Java output binding appears to only support string or byte [] which give no way to specify partition key

[pragnagopa]

PartitionKey is part of the metadata properties. https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-event-hubs#trigger---event-metadata Sending a POJO with partitionkey should work.
Need to try and add E2E test.

[pragnagopa]

cc: @mhoeger
partitionKey is part of the metadata. As of now there is no support for sending metadata as part of invocation response that is defined in the protobuff FunctionRpc.proto#L245-L257

[pragnagopa]

cc: @paulbatum

[pragnagopa]

cc @kulkarnisonia16

[pragnagopa]

Related issue on EventHubs extension: Azure/azure-sdk-for-net#28245

[pragnagopa]

given the context in Azure/azure-sdk-for-net#28245, @amamounelsayed please sync up @alrod before finalizing structure of the EventHubMessage Type.

[pragnagopa]

cc @mathewc
Related issue Azure/azure-functions-host#364. As of now webjobs sdk does
not support setting any properties on the output binding via IAsyncCollector.

Note: AsyncCollector.cs is used by functions host to send output binding content to extensions sdk

[amamounelsayed]

@pragnagopa this is the example that I was talking about https://docs.microsoft.com/en-us/java/api/com.microsoft.azure.functions.annotation.tableoutput?view=azure-java-stable

Or https://github.com/Azure/azure-functions-java-worker/blob/dev/endtoendtests/src/main/java/com/microsoft/azure/functions/endtoend/TableTests.java

I need to test it to make sure it is working.

[pragnagopa]

@amamounelsayed - Please look through table extension sdk and to confirm how partitionkey is being set on the output binding

[pragnagopa]

Here is the POCO to TableEntity converter that is taking care of populating partitionKey:

https://github.com/Azure/azure-webjobs-sdk/blob/23e180a6b2a2877d89f0eb42de1afe3a4beda4f2/src/Microsoft.Azure.WebJobs.Extensions.Storage/Tables/PocoToTableEntityConverter.cs#L62-L65

[fabiocav]

This is being handled with an out-of-band update. Closing as there's no action to be taken