Documentation
¶
Overview ¶
Package hlog (HTTP log) provides HTTP request and response logging.
The package follows a design philosophy of providing both high-level convenience functions and low-level building blocks. This approach gives users the flexibility to either use the simple, ready-to-use solutions or build custom logging with fine-grained control when needed.
Core Components ¶
- MiddlewareFunc: The standard middleware pattern for HTTP handlers
- Response: A structured container for response metrics
- RecordResponse: A high-level utility that executes handlers while collecting metrics
- Duration and StatusCode: Low-level middleware components for selective metric collection
- Interceptor: A ResponseWriter wrapper that captures HTTP response details
Design Benefits ¶
The package offers a balance between convenience and flexibility:
- RecordResponse activates all metrics collection for simple cases
- Individual middleware components can be used selectively when ResponseWriter wrapping might cause interface compatibility issues (e.g., with http.Flusher)
- Separation between metric collection and logging
Basic Usage ¶
Using the convenience middleware for standard logging:
// Create a middleware that logs request details with slog
logger := hlog.Middleware(slog.Default())
// Apply it to your handler
http.Handle("/", logger(yourHandler))
Advanced Usage ¶
Building custom middleware with the lower-level components:
var duration time.Duration h := Duration(&duration)(yourHandler) h.ServeHTTP(w, r) slog.Info(..., "duration", duration)
With status code tracking:
var status int h := StatusCode(&status)(yourHandler) h.ServeHTTP(w, r) slog.Info(..., "status", status)
Using the RecordResponse function:
rr := RecordResponse(yourHandler, w, r) slog.Info(..., "status", rr.StatusCode)
Using the Interceptor type to intercept HTTP status codes:
var status int
w := Interceptor{
ResponseWriter: w,
OnWriteHeader: func(code int) { status = code },
}
yourHandler.ServeHTTP(w, r)
slog.Info(..., "status", status)
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Interceptor ¶
type Interceptor struct {
http.ResponseWriter
OnWriteHeader func(code int)
}
Interceptor provides hooks to intercept response writes.
func (*Interceptor) Unwrap ¶
func (ic *Interceptor) Unwrap() http.ResponseWriter
Unwrap returns the embedded http.ResponseWriter to allow handlers to access the original when needed to preserve http optional interfaces like http.Flusher, etc.
func (*Interceptor) WriteHeader ¶
func (ic *Interceptor) WriteHeader(code int)
WriteHeader calls the [Interceptor.OnWriteHeader] if any and then forwards the call to the original ResponseWriter's WriteHeader method.
type MiddlewareFunc ¶
MiddlewareFunc is a function that wraps an http.Handler.
func Duration ¶
func Duration(d *time.Duration) MiddlewareFunc
Duration measures how long a request takes to process by recording the time before and after the handler executes. It uses a pointer parameter to store the result, allowing it to be used as a building block. Not safe for concurrent use. Use it only to process a single request.
func Middleware ¶
func Middleware(lg *slog.Logger) MiddlewareFunc
Middleware returns a middleware that logs requests and responses.
func StatusCode ¶
func StatusCode(n *int) MiddlewareFunc
StatusCode records the HTTP status code into the provided variable. It wraps the handler's http.ResponseWriter with Interceptor. Not safe for concurrent use. Use it only to process a single request.
type Response ¶
Response holds response related details such as duration.
func RecordResponse ¶
RecordResponse wraps an HTTP handler and captures its response details.
Source Files