package middleware
import (
"log/slog"
"net/http"
"time"
)
// LoggingMiddlewareDeps contains dependencies for the logging middleware.
type LoggingMiddlewareDeps struct {
RootLogger *slog.Logger
}
// LoggingMiddleware wraps an http.RoundTripper to add structured logging.
type LoggingMiddleware struct {
transport http.RoundTripper
logger *slog.Logger
}
// NewLoggingMiddleware creates a new logging middleware.
func NewLoggingMiddleware(transport http.RoundTripper, deps LoggingMiddlewareDeps) http.RoundTripper {
return &LoggingMiddleware{
transport: transport,
logger: deps.RootLogger.WithGroup("http-logging-middleware"),
}
}
// RoundTrip implements http.RoundTripper interface.
// Logs request and response details with structured logging.
func (l *LoggingMiddleware) RoundTrip(req *http.Request) (*http.Response, error) {
start := time.Now()
// Log request
l.logger.DebugContext(req.Context(), "HTTP request started",
slog.String("method", req.Method),
slog.String("url", req.URL.String()),
slog.String("host", req.Host),
)
// Call next transport
resp, err := l.transport.RoundTrip(req)
duration := time.Since(start)
// Log response
if err != nil {
l.logger.ErrorContext(req.Context(), "HTTP request failed",
slog.String("method", req.Method),
slog.String("url", req.URL.String()),
slog.Duration("duration", duration),
slog.Any("error", err),
)
return nil, err
}
l.logger.DebugContext(req.Context(), "HTTP request completed",
slog.String("method", req.Method),
slog.String("url", req.URL.String()),
slog.Int("status_code", resp.StatusCode),
slog.Duration("duration", duration),
)
return resp, nil
}
