CachedSchemaRegistry getting 404 response codes

[jonathansant]

Description

I was playing around with the following example: https://github.com/confluentinc/confluent-kafka-dotnet/blob/master/examples/AvroSpecific/Program.cs using our schema registry.

I started getting a 404 from the schema registry.

How to reproduce

• Set SchemaRegistryUrl to https://xxx.dev/schema-registry
• Run the program
• Examine the requests using Fiddler:
  -- Expected: https://xxx.dev/schema-registry/subjects/sucrose-external-value/versions
  -- Actual: https://xxx.dev/subjects/sucrose-external-value/versions

I tracked down the issue and it seems that there's some weird functionality when using HttpClient. Basically when adding prepending the / here:

confluent-kafka-dotnet/src/Confluent.SchemaRegistry/Rest/RestService.cs

Line 234 in 98edaaf

=> await RequestListOfAsync<int>($"/subjects/{subject}/versions", HttpMethod.Get)

causes HttpClient to discard part of the url.

Checklist

Please provide the following information:

• A complete (i.e. we can run it), minimal program demonstrating the problem. No need to supply a project file.
• Confluent.Kafka nuget version.
• Apache Kafka version.
• Client configuration.
• Operating system.
• Provide logs (with "debug" : "..." as necessary in configuration).
• Provide broker log excerpts.
• Critical issue.

[jonathansant]

Any news on this, please?

[mhowlett]

thanks for the PR! closing this issue in favor of that.