Metric - HTTP Client Example

Code Source: https://github.com/gogf/examples/tree/main/observability/metric/http_client

Description

This example demonstrates how to collect and monitor HTTP client metrics in GoFrame using OpenTelemetry and Prometheus integration. It shows how to:

• Monitor HTTP client requests
• Track request durations
• Collect response status codes
• Export client-side metrics

Structure

- `go.mod`: The Go module file for dependency management
- `go.sum`: The Go module checksums file
- `main.go`: The main application demonstrating HTTP client metrics

Features

The example showcases the following metrics:

1. Request Metrics

   • Total requests count
   • Active requests
   • Request duration
   • Request size

2. Response Metrics

   • Response status codes
   • Response size
   • Error count
   • Response duration

3. Connection Metrics

   • Connection pool stats
   • DNS lookup duration
   • TLS handshake duration

Requirements

• Go 1.22 or higher
• Git
• GoFrame
• GoFrame OpenTelemetry Metric

Usage

1. Run the example:

   go run main.go

2. Access the metrics:

   # Using curl
   curl http://localhost:8000/metrics
   
   # Or open in browser
   http://localhost:8000/metrics

3. Example metrics output:

   # HELP goframe_http_client_request_duration_seconds Duration of HTTP requests
   goframe_http_client_request_duration_seconds_bucket{method="GET",status="200",url="https://goframe.org",le="0.1"} 1
   
   # HELP goframe_http_client_requests_total Total number of HTTP requests made
   goframe_http_client_requests_total{method="GET",status="200",url="https://goframe.org"} 1
   
   # HELP goframe_http_client_response_size_bytes Size of HTTP response payloads
   goframe_http_client_response_size_bytes{method="GET",status="200",url="https://goframe.org"} 12345

Implementation Details

The example demonstrates:

1. HTTP client configuration
2. Automatic metric collection
3. Built-in metrics integration
4. Prometheus export setup
5. Metric attribute handling

Notes

• Metrics are collected automatically
• No manual instrumentation needed
• Built-in metrics are enabled by default
• Supports all HTTP methods
• Tracks all response codes
• Default port is 8000
• Metrics endpoint is at /metrics
• Consider security implications when exposing metrics