gRPC/tonic automatic instrumentation

[ibrahimcesar]

Automatic instrumentation for gRPC services built with tonic.

Goals

• Zero-config instrumentation for tonic services
• Track all RPC calls with async-inspect
• Propagate trace context through gRPC metadata

Features

• Tower layer for automatic instrumentation
• Capture request/response metadata
• Streaming RPC support
• Error tracking and status codes

Acceptance Criteria

• All tonic RPCs automatically tracked
• Trace context propagated in metadata
• Streaming RPCs show correct timeline
• Works with interceptors and middleware