refactor: refine HTTP response body logging, explicitly handling 204 No Content, and improving error management for body reads

pkg/srv/http/http_log.go

@@ -3,7 +3,8 @@ package http
 import (
 	"bytes"
 	"context"
-	"errors"
+	"fmt"
+	"io"
 	"net/http"
 	"regexp"
 	"time"
@@ -41,25 +42,38 @@ func loggingMiddleware(appCtx context.Context, next http.Handler) http.Handler {
 			Dur("duration", time.Since(start)).
 			Msg("http request served")
 
-		// Log response with body if not 204
-		if lrr.statusCode != http.StatusNoContent {
+			// Log response with body if not 204
+		if lrr.statusCode == http.StatusNoContent {
 			trcLog := log.Trace().
 				Str("path", r.URL.Path).
 				Int("statusCode", lrr.statusCode)
-			firstByte, err := lrr.body.ReadByte()
-			if err != nil {
-				trcLog.Err(errors.New("invalid response body")).Send()
-				return
-			}
-			lrr.body.UnreadByte()
-
-			if firstByte == '{' {
-				trcLog = trcLog.RawJSON("response", lrr.body.Bytes())
-			} else {
-				trcLog = trcLog.Bytes("response", lrr.body.Bytes())
-			}
-			trcLog.Msg("http response")
+			trcLog.Msg("http response (no content)") // Explicitly log 204
+			return                                   // No body to log for 204 No Content
 		}
+
+		trcLog := log.Trace().
+			Str("path", r.URL.Path).
+			Int("statusCode", lrr.statusCode)
+
+		firstByte, err := lrr.body.ReadByte()
+		if err != nil {
+			if err == io.EOF {
+				// Body is empty, which might be valid for some non-204 responses.
+				trcLog.Msg("http response (empty body)")
+			} else {
+				// Other error reading the body. Wrap the original error for context.
+				trcLog.Err(fmt.Errorf("error reading response body: %w", err)).Send()
+			}
+			return // No further body processing if there was an error or it was empty
+		}
+		lrr.body.UnreadByte() // Put the byte back for Bytes() to read
+
+		if firstByte == '{' {
+			trcLog = trcLog.RawJSON("response", lrr.body.Bytes())
+		} else {
+			trcLog = trcLog.Bytes("response", lrr.body.Bytes())
+		}
+		trcLog.Msg("http response")
 	})
 }