handle otlp, add obs logs, test request for otlp, test for otlp

Signed-off-by: MJarmo <michal.jarmolkiewicz@sap.com>

Author: Michał Jarmolkiewicz

receiver/auditlogreceiver/examples/README.md

@@ -0,0 +1,203 @@
+# OTLP Examples for Audit Log Receiver
+
+This directory contains examples demonstrating how to send OTLP (OpenTelemetry Protocol) requests to the audit log receiver.
+
+## Files
+
+- `otlp_request_example.go` - Comprehensive Go example showing different types of OTLP requests
+- `test_otlp_client.go` - Test client that validates OTLP functionality
+- `otlp_curl_examples.md` - Examples using curl, HTTPie, and other HTTP clients
+- `README.md` - This file
+
+## Quick Start
+
+### 1. Run the Comprehensive Example
+
+```bash
+go run examples/otlp_request_example.go
+```
+
+This will create and send various types of OTLP requests to demonstrate the receiver's capabilities.
+
+### 2. Run the Test Client
+
+```bash
+go run examples/test_otlp_client.go
+```
+
+This will test all supported endpoints with different scenarios.
+
+### 3. Manual Testing with curl
+
+```bash
+# Generate OTLP data first
+go run examples/otlp_request_example.go > /dev/null
+
+# Send a simple request (you'll need to create the protobuf data)
+curl -X POST http://localhost:4310/v1/logs \
+  -H "Content-Type: application/x-protobuf" \
+  --data-binary @otlp_data.bin
+```
+
+## Supported Endpoints
+
+The receiver supports these OTLP endpoints:
+
+- `POST /v1/logs` - Standard OTLP logs endpoint
+- `POST /v1/logs/` - OTLP logs endpoint with trailing slash  
+- `POST /v1/logs/export` - OTLP logs export endpoint
+
+## Content Types
+
+The receiver accepts these content types for OTLP requests:
+
+- `application/x-protobuf`
+- `application/vnd.google.protobuf`
+
+## Example Request Structure
+
+An OTLP request contains:
+
+1. **Resource Attributes** - Service-level metadata
+2. **Scope Attributes** - Logger/component metadata  
+3. **Log Records** - Individual log entries with:
+   - Body (message)
+   - Severity level
+   - Timestamp
+   - Attributes
+
+## Response Format
+
+- **Success (200 OK)**: Empty OTLP ExportResponse
+- **Error (400 Bad Request)**: Error message for invalid protobuf
+- **Error (500 Internal Server Error)**: Error message for processing failures
+
+## Testing with OpenTelemetry SDKs
+
+You can also test using official OpenTelemetry SDKs in various languages:
+
+### Go SDK
+```go
+import (
+    "go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp"
+)
+```
+
+### Java SDK
+```java
+import io.opentelemetry.exporter.otlp.http.logs.OtlpHttpLogRecordExporter;
+```
+
+### Python SDK
+```python
+from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter
+```
+
+## Troubleshooting
+
+### Common Issues
+
+1. **Connection Refused**: Ensure the receiver is running on the correct port
+2. **Content-Type Error**: Use `application/x-protobuf` header
+3. **Invalid Protobuf**: Ensure data is valid OTLP protobuf format
+4. **Timeout**: Check receiver processing time
+
+### Debug Mode
+
+Enable debug logging in the receiver configuration:
+
+```yaml
+receivers:
+  auditlogreceiver:
+    endpoint: ":4310"
+    log_level: debug
+```
+
+### Validation
+
+Use the OpenTelemetry Collector's validation tools:
+
+```bash
+otelcol-contrib --config=config.yaml --dry-run
+```
+
+## Advanced Examples
+
+### Custom Resource Attributes
+
+```go
+resourceAttrs := resourceLogs.Resource().Attributes()
+resourceAttrs.PutStr("service.name", "audit-service")
+resourceAttrs.PutStr("service.version", "1.0.0")
+resourceAttrs.PutStr("deployment.environment", "production")
+```
+
+### Custom Scope Attributes
+
+```go
+scopeAttrs := scopeLogs.Scope().Attributes()
+scopeAttrs.PutStr("scope.name", "audit-logger")
+scopeAttrs.PutStr("scope.version", "2.1.0")
+```
+
+### Different Severity Levels
+
+```go
+logRecord.SetSeverityNumber(plog.SeverityNumberInfo)  // INFO
+logRecord.SetSeverityNumber(plog.SeverityNumberWarn)  // WARN
+logRecord.SetSeverityNumber(plog.SeverityNumberError) // ERROR
+logRecord.SetSeverityNumber(plog.SeverityNumberFatal)  // FATAL
+```
+
+## Performance Testing
+
+For performance testing, you can:
+
+1. Use the test client with multiple concurrent requests
+2. Implement rate limiting in your client
+3. Monitor receiver metrics and logs
+4. Test with different payload sizes
+
+## Integration Examples
+
+### With OpenTelemetry Collector
+
+```yaml
+receivers:
+  auditlogreceiver:
+    endpoint: ":4310"
+
+processors:
+  batch:
+
+exporters:
+  logging:
+    loglevel: debug
+
+service:
+  pipelines:
+    logs:
+      receivers: [auditlogreceiver]
+      processors: [batch]
+      exporters: [logging]
+```
+
+### With Jaeger
+
+```yaml
+receivers:
+  auditlogreceiver:
+    endpoint: ":4310"
+
+exporters:
+  jaeger:
+    endpoint: jaeger:14250
+
+service:
+  pipelines:
+    logs:
+      receivers: [auditlogreceiver]
+      exporters: [jaeger]
+```
+
+This provides a complete example of how to integrate the audit log receiver with other OpenTelemetry components.