Content Type is shown as Json, but the message is serialized with Avro

[etrandafir93]

Describe the bug

The Content-Type field on the UI is a bit misleading:

• When using SpringWolf for Kafka with an Avro serializer, the Content Type field shows application/json (the default)
• Even though the content type is displayed as application/json, publishing messages from the UI still pushes them using the Avro serializer - so bascially it says json, but it's actually using avro for the serialization, which is good.
• If I try to overwrite this with @AsyncMessage(contentType = "application/*+avro"), the UI fails to display the schema, and we cannot publish test messages (I guess this type is not supported)

Dependencies and versions used

• springwolf-ui version 1.20.0

Code example

This can also be reproduced/observed in the official avro exmaple

[timonback]

Hi @etrandafir93
Thank you for reporting this issue.

Springwolf has no detection of Avro and protobuf and relies on Spring for (de)serialisation, so manual content type in the settings globally or per channel is required.

True, the Kafka example has the same issue and the e2e test for Avro is disabled at the moment.

As the publishing functionality is built for publishing support from the Ui, it can be adapted/fixed.
What do you put into the message field in the ui ? JSON which is then converted into the wire format in the Spring backend.

If you or anyone else wants to look into it and improve it, you are welcome to do so.

[etrandafir93]

@timonback thanks for the fast reply!

What do you put into the message field in the ui ? JSON which is then converted into the wire format in the Spring backend.

Yes, having the payload displayed as JSON in the web UI, and then using the serializer configured in the Spring backend is the most convenient option (for me, at least).
This is already working great! So it can be just a matter of allowing the Content Type field (in the UI, at least) reflect it.

I see you already have some progress with this, that's awesome! :)
Let me know if I can help with anything.

[github-actions]

The change is staged for release and will be part of the next release.

If you want to try and verify it in your application today,
use the latest 1.X.0-SNAPSHOT build as described in our README.md > Testing SNAPSHOT version

Thank you for the report/contribution!

[timonback]

Hi @etrandafir93 ,

we went ahead with the PR and merged it today. You can expect to use the avro publishing feature in the next release.

Thank you for raising the issue. If you want to beta-test, you can try out the SNAPSHOT version.