SigV4 Log Exporter

[Jeel-mehta]

Description of changes:

This PR introduces an OTLP Log Exporter implementation that enables sending logs to AWS CloudWatch using the OTLP endpoint. The implementation has been tested via manual instrumentation and successfully delivers logs to CloudWatch.

Key Components

• OtlpAwsLogExporter.cs: Main exporter implementation with AWS SigV4 authentication support
• OtlpExporterUtils.cs: Utility class for OTLP serialization using reflection

Features

• AWS SigV4 authentication for secure log delivery
• Configurable log group and stream support
• Retry mechanism with exponential backoff
• Proper error handling and logging
• Compatible with OpenTelemetry Protocol specification

Configuration

The exporter requires the following environment variables:

OTEL_EXPORTER_OTLP_LOGS_ENDPOINT=https://logs.[AWSRegion].amazonaws.com/v1/logs
OTEL_AWS_SIG_V4_ENABLED=true
OTEL_EXPORTER_OTLP_LOGS_HEADERS=x-aws-log-group=your-log-group,x-aws-log-stream=your-log-stream

Current Limitations

Auto-instrumentation is not yet available as the upstream OpenTelemetry implementation does not currently provide a way to customize the LogProvider. This will be addressed in future updates once upstream support becomes available.

Testing

The implementation has been manually tested with the following scenarios:

• Successfully sending logs to CloudWatch
• Proper authentication using AWS credentials
• Retry mechanism for failed requests
• Correct log group and stream mapping

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