ServiceBusWireTap.Middleware.Logging 1.0.0

📦 Service Bus WireTap Middleware for .NET Isolated Azure Functions

A reusable middleware for Azure Functions (.NET 8+ Isolated Worker), enabling wire‑tap-style logging of complete ServiceBusReceivedMessage—capturing body, metadata, and application properties—regardless of typed function signatures.

Part of the WireTapMiddleware collection for messaging broker interception.

🔍 Key Features

• Works seamlessly with typed bindings (e.g., POCOs), yet taps the full ServiceBusReceivedMessage for deep visibility
• Built on IFunctionsWorkerMiddleware, intercepting messages in a central place, no per-function changes needed
• Logs MessageId, CorrelationId, full body text, and all ApplicationProperties
• Integrates with built-in logging (Application Insights/ILogger)
• Configurable logging options for security and performance
• Custom log actions for integration with external systems

🚀 Quick Start

1. Install the Package

dotnet add package ServiceBusWireTap.Middleware.Logging

2. Register the Middleware

In your Program.cs:

using Microsoft.Extensions.Hosting;
using ServiceBusWireTap.Middleware.Logging;

var host = new HostBuilder()
    .UseServiceBusWireTap() // Add this line
    .ConfigureFunctionsWorkerDefaults()
    .Build();

host.Run();

3. Your Functions Work Unchanged

[Function("ProcessOrder")]
public async Task ProcessOrder([ServiceBusTrigger("orders", Connection = "ServiceBus")] Order order)
{
    // Your business logic here - unchanged!
    // The middleware automatically logs the complete ServiceBusReceivedMessage
}

⚙️ Configuration Options

Basic Configuration

var host = new HostBuilder()
    .UseServiceBusWireTap(options =>
    {
        options.LogLevel = LogLevel.Information;
        options.IncludeMessageBody = true;
        options.MaxBodySizeToLog = 10 * 1024; // 10KB
    })
    .ConfigureFunctionsWorkerDefaults()
    .Build();

Advanced Configuration with Custom Actions

var host = new HostBuilder()
    .UseServiceBusWireTap(options =>
    {
        options.LogLevel = LogLevel.Debug;
        options.IncludeMessageBody = false; // Don't log body for security
        options.CustomLogAction = async (logEntry) =>
        {
            // Send to custom telemetry system
            await CustomTelemetryClient.SendAsync(logEntry);
        };
    })
    .ConfigureFunctionsWorkerDefaults()
    .Build();

🔧 Configuration Options Reference

🛡️ Security Considerations

For sensitive data, consider:

.UseServiceBusWireTap(options =>
{
    options.IncludeMessageBody = false; // Exclude body for sensitive data
    options.MaxBodySizeToLog = 1024;    // Limit body size
})

🔍 Example Function Types Supported

POCO Binding

[Function("ProcessOrder")]
public async Task ProcessOrder([ServiceBusTrigger("orders")] Order order)
{
    // Middleware logs the complete ServiceBusReceivedMessage
    // Your function gets the typed Order object
}

String Binding

[Function("ProcessMessage")]
public async Task ProcessMessage([ServiceBusTrigger("messages")] string message)
{
    // Middleware logs full message details
    // Your function gets the string body
}

ServiceBusReceivedMessage Binding

[Function("ProcessRawMessage")]
public async Task ProcessRawMessage([ServiceBusTrigger("raw")] ServiceBusReceivedMessage message)
{
    // Middleware logs the message
    // Your function gets the raw message object
}

🔄 Integration with Application Insights

The middleware integrates seamlessly with Application Insights:

// In your Function App configuration
builder.Services.AddApplicationInsightsTelemetryWorkerService();

// Wire-tap logs will appear in Application Insights with custom properties
// Query example:
// traces | where message contains "ServiceBus Message Intercepted"

🎯 Use Cases

• Message Auditing: Track all ServiceBus messages for compliance
• Debugging: Deep visibility into message flow without code changes
• Monitoring: Real-time insights into message processing
• Analytics: Custom telemetry integration for business intelligence

🔮 Future Brokers

This is part of the WireTapMiddleware collection. Future implementations will include:

• RabbitMQ WireTap Middleware
• Apache Kafka WireTap Middleware
• Amazon SQS WireTap Middleware

📝 License

This project is licensed under the MIT License.

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.