Fix CURL logging, unexport some types

Author: VojtechVitek

README.md

@@ -14,9 +14,13 @@ A small but powerful structured logging package for HTTP request logging, built
 
 See [_example/main.go](./_example/main.go). Try running it locally:
 ```sh
-$ ENV=production go run github.com/golang-cz/httplog/_example
+$ cd _example
 
-$ ENV=localhost go run github.com/golang-cz/httplog/_example
+# JSON logger
+$ ENV=production go run .
+
+# pretty logger
+$ ENV=localhost go run .
 ```
 
 ## Usage
@@ -64,7 +68,7 @@ func main() {
 		// RecoverPanics recovers from panics occurring in the underlying HTTP handlers
 		// and middlewares. It returns HTTP 500 unless response status was already set.
 		//
-		// NOTE: The request logger logs all panics automatically, regardless of this setting.
+		// NOTE: Panics are logged as errors automatically, regardless of this setting.
 		RecoverPanics: true,
 
 		// Select request/response headers to be logged explicitly.

_example/main.go

@@ -62,7 +62,7 @@ func main() {
 		// RecoverPanics recovers from panics occurring in the underlying HTTP handlers
 		// and middlewares. It returns HTTP 500 unless response status was already set.
 		//
-		// NOTE: The request logger logs all panics automatically, regardless of this setting.
+		// NOTE: Panics are logged as errors automatically, regardless of this setting.
 		RecoverPanics: true,
 
 		// Select request/response headers to be logged explicitly.

context.go

@@ -2,7 +2,6 @@ package httplog
 
 import (
 	"context"
-	"fmt"
 	"io"
 	"log/slog"
 )
@@ -17,7 +16,7 @@ func (c *logCtxKey) String() string {
 //
 // NOTE: Not safe for concurrent access. Don't use outside of HTTP request goroutine.
 func SetAttrs(ctx context.Context, attrs ...slog.Attr) {
-	log, ok := ctx.Value(logCtxKey{}).(*Log)
+	log, ok := ctx.Value(logCtxKey{}).(*log)
 	if !ok {
 		// Panic to stress test the use of this function. Later, we can return error.
 		panic("use of httplog.SetAttrs() outside of context set by httplog.RequestLogger")
@@ -30,7 +29,7 @@ func SetAttrs(ctx context.Context, attrs ...slog.Attr) {
 //
 // NOTE: Not safe for concurrent access. Don't use outside of HTTP request goroutine.
 func SetLevel(ctx context.Context, level slog.Level) {
-	log, ok := ctx.Value(logCtxKey{}).(*Log)
+	log, ok := ctx.Value(logCtxKey{}).(*log)
 	if !ok {
 		// Panic to stress test the use of this function. Later, we can return error.
 		panic("use of httplog.SetLevel() outside of context set by httplog.RequestLogger")
@@ -39,23 +38,22 @@ func SetLevel(ctx context.Context, level slog.Level) {
 }
 
 func LogRequestBody(ctx context.Context) {
-	log, ok := ctx.Value(logCtxKey{}).(*Log)
+	log, ok := ctx.Value(logCtxKey{}).(*log)
 	if !ok {
 		// Panic to stress test the use of this function. Later, we can return error.
-		panic("use of httplog.SetLevel() outside of context set by httplog.RequestLogger")
+		panic("use of httplog.LogRequestBody() outside of context set by httplog.RequestLogger")
 	}
 	if !log.LogRequestBody {
-		fmt.Println("doing it now...")
 		log.LogRequestBody = true
 		log.Req.Body = io.NopCloser(io.TeeReader(log.Req.Body, &log.ReqBody))
 	}
 }
 
 func LogResponseBody(ctx context.Context) {
-	log, ok := ctx.Value(logCtxKey{}).(*Log)
+	log, ok := ctx.Value(logCtxKey{}).(*log)
 	if !ok {
 		// Panic to stress test the use of this function. Later, we can return error.
-		panic("use of httplog.SetLevel() outside of context set by httplog.RequestLogger")
+		panic("use of httplog.LogResponseBody() outside of context set by httplog.RequestLogger")
 	}
 	if !log.LogResponseBody {
 		log.LogResponseBody = true

handler.go

@@ -37,14 +37,14 @@ func (h *Handler) Handle(ctx context.Context, rec slog.Record) error {
 		panic("use of httplog.DefaultHandler outside of context set by http.RequestLogger middleware")
 	}
 
-	if h.opts.LogRequestCURL {
-		rec.AddAttrs(slog.String("curl", log.curl()))
-	}
-
 	if h.opts.Concise {
 		reqAttrs := []slog.Attr{}
 		respAttrs := []slog.Attr{}
 
+		if log.LogRequestCURL {
+			reqAttrs = append(reqAttrs, slog.String("curl", log.curl()))
+		}
+
 		reqAttrs = append(reqAttrs, slog.Any("headers", slog.GroupValue(getHeaderAttrs(log.Req.Header, h.opts.LogRequestHeaders)...)))
 		if log.LogRequestBody && log.Resp != nil {
 			reqAttrs = append(reqAttrs, slog.String("body", log.ReqBody.String()))
@@ -63,7 +63,7 @@ func (h *Handler) Handle(ctx context.Context, rec slog.Record) error {
 			rec.Message = fmt.Sprintf("%s %s://%s%s", log.Req.Method, log.scheme(), log.Req.Host, log.Req.URL)
 		}
 
-		if log.WW.Status() >= 400 {
+		if log.WW.Status() >= 400 || log.Level == slog.LevelDebug {
 			rec.AddAttrs(slog.Any("request", slog.GroupValue(reqAttrs...)))
 			rec.AddAttrs(slog.Any("response", slog.GroupValue(respAttrs...)))
 		}
@@ -77,12 +77,18 @@ func (h *Handler) Handle(ctx context.Context, rec slog.Record) error {
 			slog.String("proto", log.Req.Proto),
 			slog.Any("headers", slog.GroupValue(getHeaderAttrs(log.Req.Header, h.opts.LogRequestHeaders)...)),
 		}
+
+		if log.LogRequestCURL {
+			reqAttrs = append(reqAttrs, slog.String("curl", log.curl()))
+		}
+
 		if log.LogRequestBody && log.Resp != nil {
 			reqAttrs = append(reqAttrs, slog.String("body", log.ReqBody.String()))
 			if !log.ReqBodyFullyRead {
 				reqAttrs = append(reqAttrs, slog.Bool("bodyFullyRead", false))
 			}
 		}
+
 		rec.AddAttrs(slog.Any("request", slog.GroupValue(reqAttrs...)))
 
 		if log.Resp != nil {

logger.go

@@ -40,47 +40,68 @@ type Options struct {
 	// slog.LevelInfo  - log responses (excl. OPTIONS)
 	// slog.LevelWarn  - log 4xx and 5xx responses only (except for 429)
 	// slog.LevelError - log 5xx responses only
+	//
+	// Use httplog.SetLevel(ctx, slog.DebugLevel) to override the level per-request.
 	Level slog.Level
 
 	// Concise mode causes fewer log attributes to be printed in request logs.
 	// This is useful if your console is too noisy during development.
 	Concise bool
 
 	// RecoverPanics recovers from panics occurring in the underlying HTTP handlers
-	// and middlewares. It returns HTTP 500 unless response status was already set.
+	// and middlewares and returns HTTP 500 unless response status was already set.
 	//
-	// NOTE: The request logger logs all panics automatically, regardless of this setting.
+	// NOTE: Panics are logged as errors automatically, regardless of this setting.
 	RecoverPanics bool
 
 	// LogRequestHeaders is an explicit list of headers to be logged as attributes.
+	// If not provided, the default headers are User-Agent, Referer and Origin.
 	LogRequestHeaders []string
 
 	// LogRequestBody enables logging of request body into a response log attribute.
+	//
+	// Use httplog.LogRequestBody(ctx) to enable on per-request basis instead.
 	LogRequestBody bool
 
+	// LogRequestCURL enables logging of request body incl. all headers as a CURL command.
+	//
+	// Use httplog.LogRequestCURL(ctx) to enable on per-request basis instead.
+	LogRequestCURL bool
+
 	// LogResponseHeaders is an explicit list of headers to be logged as attributes.
+	//
+	// If not provided, there are no default headers.
 	LogResponseHeaders []string
 
 	// LogResponseBody enables logging of response body into a response log attribute.
+	// The Content-Type of the response must match.
+	//
+	// Use httplog.LogResponseBody(ctx) to enable on per-request basis instead.
 	LogResponseBody bool
+
+	// LogResponseBodyContentType defines list of Content-Types for which LogResponseBody is enabled.
+	//
+	// If not provided, the default list is application/json and text/plain.
+	LogResponseBodyContentType []string
 }
 
 var defaultOptions = Options{
-	Level:              slog.LevelInfo,
-	Concise:            false,
-	RecoverPanics:      true,
-	LogRequestHeaders:  []string{"User-Agent", "Referer", "Origin"},
-	LogResponseHeaders: []string{""},
+	Level:                      slog.LevelInfo,
+	RecoverPanics:              true,
+	LogRequestHeaders:          []string{"User-Agent", "Referer", "Origin"},
+	LogResponseHeaders:         []string{""},
+	LogResponseBodyContentType: []string{"application/json", "text/plain"},
 }
 
 func (l *Logger) Handle(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		ctx := r.Context()
 
-		log := &Log{
+		log := &log{
 			Level:           l.opts.Level,
 			Req:             r,
-			LogRequestBody:  l.opts.LogRequestBody,
+			LogRequestCURL:  l.opts.LogRequestCURL,
+			LogRequestBody:  l.opts.LogRequestBody || l.opts.LogRequestCURL,
 			LogResponseBody: l.opts.LogResponseBody,
 		}
 
@@ -121,7 +142,7 @@ func (l *Logger) Handle(next http.Handler) http.Handler {
 
 			status := ww.Status()
 
-			log.Resp = &ResponseLog{
+			log.Resp = &respLog{
 				Header:   w.Header,
 				Duration: time.Since(start),
 			}
@@ -153,24 +174,27 @@ func (l *Logger) Handle(next http.Handler) http.Handler {
 	})
 }
 
-type Log struct {
-	Level           slog.Level  // Use httplog.SetLevel(ctx, slog.DebugLevel) to override level
-	Attrs           []slog.Attr // Use httplog.SetAttrs(ctx, slog.String("key", "value")) to append
-	LogRequestBody  bool        // Use httplog.LogRequestBody(ctx) to force-enable
-	LogResponseBody bool        // Use httplog.LogResponseBody(ctx) to force-enable
+type log struct {
+	Level           slog.Level
+	Attrs           []slog.Attr
+	LogRequestCURL  bool
+	LogRequestBody  bool
+	LogResponseBody bool
 
-	// Fields automatically set by httplog.RequestLogger middleware:
+	// Fields set by httplog.RequestLogger middleware:
 	Req              *http.Request
 	ReqBody          bytes.Buffer
 	ReqBodyFullyRead bool
 	WW               middleware.WrapResponseWriter
-	Resp             *ResponseLog
+	Resp             *respLog
 	RespBody         bytes.Buffer
 	Panic            any
 	PanicPC          []uintptr
+
+	// Fields internal to httplog:
 }
 
-type ResponseLog struct {
+type respLog struct {
 	Header   func() http.Header
 	Duration time.Duration
 }