Schema Registry Exception details missing

[cyandaniel]

Description

We tried to produce messages from a docker container behind a company proxy to an internal host. Due to system environment misconfiguration the schema client connection to the registy is made through that proxy. The response from the proxy was an HTML web page with the content "DNS Error. Please contact..."

The RestClient throws an SchemaRegistryException with no message, erroCode = -1 and status = null. So its a little bit hard to find out whats going on.

A possible solution could be to add the exception that is currently being caught but not processed as an InnerException to the SchemaRegistryException.

How to reproduce

• Create a simple fake api, which returns anything than valid json
• Use fake api endpoint as SchemaRegistryUrl
• Get Exception

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.
• [x ] Confluent.Kafka nuget version. 2.3.0
• [ ] Apache Kafka version.
• [ ] Client configuration.
• [ ] Operating system.
• [ ] Provide logs (with "debug" : "..." as necessary in configuration).
• [ ] Provide broker log excerpts.
• [ ] Critical issue.

[pfeigl]

The relevant code should be this here where the exception is caught but completely discarded https://github.com/confluentinc/confluent-kafka-dotnet/blob/a67bd6c06b7eef4293e6476d9ff6f3e93f0e4cd9/src/Confluent.SchemaRegistry/Rest/RestService.cs#L201

Also while looking into this. Why does the SchemaRegistryException have it's own Status property and does not use the StatsCode property of the base HttpRequestException class?