Support Kafka Connect Cluster Behind Two-Way SSL

[yeikel]

Issue submitter TODO list

• I've searched for an already existing issues here
• I'm running a supported version of the application which is listed here and the feature is not present there

Is your proposal related to a problem?

Currently, the UI cannot connect to a remote Kafka Connect cluster that requires two-way SSL (mutual TLS) for authentication. This limitation prevents users from managing or interacting with Kafka Connect clusters that enforce client certificate authentication. As a result, environments that require mTLS for security cannot be accessed through the UI

Describe the feature you're interested in

The UI should allow users to configure a client certificate and private key that will be used when making HTTP requests to a Kafka Connect cluster. This would enable the UI backend to authenticate using two-way SSL (mutual TLS) when communicating with Kafka Connect. The configuration should allow securely providing the private key and certificate so that the UI can successfully connect to Kafka Connect clusters that require client certificate authentication.

Describe alternatives you've considered

Deploy a proxy in between the UI and the destination Kafka Connect Cluster

Version you're running

ec46dff

Additional context

No response

[yeikel]

Actually, I may be wrong as this may be possible today: https://github.com/kafbat/kafka-ui/blame/ec46dff2360308ed0d95c784139ab3d352c5c7da/api/src/main/java/io/kafbat/ui/client/RetryingKafkaConnectClient.java#L341-L348