New - Enable Proxy Support for Declarative Configs

[cleverchuk]

Summary

This PR adds HTTP proxy support to the declarative configuration system and migrates all signal exporters (traces, metrics, logs) from gRPC to HTTP/protobuf protocol with custom SolarWinds component providers.

Changes

New Components

ProxyParser

A new parser that extracts proxy configuration from DeclarativeConfigProperties using the agent.proxy key. Delegates to the existing ProxyConfigParser for URL parsing and validation.

LogExporterComponentProvider

Custom OpenTelemetry ComponentProvider for log exports:

• Registered as swo/logExporter via @AutoService
• Uses OtlpHttpLogRecordExporter (HTTP/protobuf)
• Configures proxy from ConfigManager if available

SpanExporterComponentProvider

Custom OpenTelemetry ComponentProvider for trace exports:

• Registered as swo/spanExporter via @AutoService
• Uses OtlpHttpSpanExporter (HTTP/protobuf)
• Configures proxy from ConfigManager if available

Modified Components

MetricExporterComponentProvider

• Protocol change: Migrated from OtlpGrpcMetricExporter to OtlpHttpMetricExporter
• Proxy support: Added proxy configuration from ConfigManager

SharedConfigCustomizerProvider

Key changes:

1. Proxy parsing: Added parseProxyConfig() to extract and store proxy settings during configuration customization
2. Refactored config access: Extracted getSolarwindsConfig() method to centralize retrieval of SolarWinds-specific configuration with null validation
3. Span exporter: Replaced OtlpGrpcExporterModel with custom SpanExporterComponentProvider using SpanExporterPropertyModel
4. Log exporter: Replaced OtlpGrpcExporterModel with custom LogExporterComponentProvider using LogRecordExporterPropertyModel
5. Signal-specific endpoints: Added OTLP standard paths to endpoints:
   • Traces: {endpoint}/v1/traces
   • Metrics: {endpoint}/v1/metrics
   • Logs: {endpoint}/v1/logs
6. Protocol update: Changed metric exporter protocol from grpc to http/protobuf
7. Removed: createModel() method (no longer needed after migration away from OtlpGrpcExporterModel)

File Relocations

• ProxyConfigParser.java: Moved from custom/ to libs/shared/ for shared access

Technical Rationale

HTTP/protobuf over gRPC

The migration to HTTP/protobuf provides:

• Better proxy compatibility (HTTP proxies don't require gRPC-specific handling)
• Simpler network configuration in enterprise environments
• Consistent protocol across all signal types

Custom Component Providers

Using withAdditionalProperty() pattern with custom component providers allows:

• Proxy injection at exporter creation time
• Centralized configuration through ConfigManager
• Consistent configuration model across spans, metrics, and logs

Centralized Proxy Configuration

Proxy settings are parsed once during model customization and stored in ConfigManager, making them available to all component providers during exporter creation.

Tests Added

Test Class	Coverage
LogExporterComponentProviderTest	Component name, type verification
SpanExporterComponentProviderTest	Component name, type verification
ProxyParserTest	Config key, null handling, proxy parsing with/without credentials
MetricExporterComponentProviderTest	Added testGetType() for consistency
SharedConfigCustomizerProviderTest	Updated assertions for new endpoint paths (/v1/logs, /v1/metrics)

Test services data

1. e-1712644058766987264
2. e-1712643928659124224
3. e-1742334541200846848
4. e-1777406072376840192