Description

Currently both confighttp and configgrpc set the client address based only one value RemoteAddress or the Peer information espectively. The PR adds the flexibility to the determine the client address based on the request metadata using a new config client_address_metadata_keys. If this value is empty or no valid IP is found in the metadata, the client address falls back to RemoteAddress or the Peer information to be backwards compatible

Link to tracking issue

Fixes #14186

Testing

1. Updated unit test

2. Created local collector which imports the attributes processor and ingested data

   Local Collector Details

   • Exported data using telemetrygen logs --otlp-insecure 1 --otlp-header x-forwarded-for=\"1.1.1.1\"
   • Collector config
     • Note this required adding github.com/open-telemetry/opentelemetry-collector-contrib/processor/attributesprocesso to components.go and other files in cmd/otelcorecol

   extensions:
     zpages:
       endpoint: localhost:55679
   
   receivers:
     otlp:
       protocols:
         grpc:
           endpoint: localhost:4317
           client_address_metadata_keys:
             - x-forwarded-for
         http:
           endpoint: localhost:4318
           client_address_metadata_keys:
             - x-forwarded-for
   
   processors:
     attributes/example:
       actions:
         - key: client.addr
           action: upsert
           from_context: client.address
     memory_limiter:
       # 75% of maximum memory up to 2G
       limit_mib: 1536
       # 25% of limit up to 2G
       spike_limit_mib: 512
       check_interval: 5s
   
   exporters:
     debug:
       verbosity: detailed
   
   service:
     pipelines:
       traces:
         receivers: [otlp]
         processors: [attributes/example]
         exporters: [debug]
       metrics:
         receivers: [otlp]
         processors: [attributes/example]
         exporters: [debug]
       logs:
         receivers: [otlp]
         processors: [attributes/example]
         exporters: [debug]
   
     extensions: [zpages]
   

   • Verified the following collector debug output:

     2025-11-26T08:54:36.615-0800    info    ResourceLog #0
     Resource SchemaURL: https://opentelemetry.io/schemas/1.25.0
     Resource attributes:
          -> service.name: Str(telemetrygen)
     ScopeLogs #0
     ScopeLogs SchemaURL: 
     InstrumentationScope  
     LogRecord #0
     ObservedTimestamp: 1970-01-01 00:00:00 +0000 UTC
     Timestamp: 2025-11-26 16:54:36.585084 +0000 UTC
     SeverityText: Info
     SeverityNumber: Info(9)
     Body: Str(the message)
     Attributes:
          -> app: Str(server)
          -> client.addr: Str(1.1.1.1)
     Trace ID: 
     Span ID: 
     

Documentation

• Updated the confighttp and configgrpc README.md files