Replace API Debug Middleware

internal/api/api.go

@@ -90,7 +90,7 @@
 	handler = versionHeaderMiddleware(config.AppVersion)(handler)
 	if config.Debug {
 		handler = goahttpmwr.Log(loggerAdapter(logger))(handler)
-		handler = goahttpmwr.Debug(mux, os.Stdout)(handler)
+		handler = Debug(mux, os.Stdout)(handler)
 	}
 
 	return &http.Server{

internal/api/debug_middleware.go

@@ -0,0 +1,140 @@
+package api
+
+import (
+	"bufio"
+	"bytes"
+	"crypto/rand"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"sort"
+	"strings"
+
+	goahttp "goa.design/goa/v3/http"
+	"goa.design/goa/v3/middleware"
+)
+
+// Debug returns a debug middleware which prints detailed information about
+// incoming requests and outgoing responses including all headers, parameters
+// and bodies.
+func Debug(mux goahttp.Muxer, w io.Writer) func(http.Handler) http.Handler {
+	return func(h http.Handler) http.Handler {
+		return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+			buf := &bytes.Buffer{}
+			// Request ID
+			reqID := r.Context().Value(middleware.RequestIDKey)
+			if reqID == nil {
+				reqID = shortID()
+			}
+
+			// Request URL
+			buf.WriteString(fmt.Sprintf("> [%s] %s %s", reqID, r.Method, r.URL.String()))
+
+			// Request Headers
+			keys := make([]string, len(r.Header))
+			i := 0
+			for k := range r.Header {
+				keys[i] = k
+				i++
+			}
+			sort.Strings(keys)
+			for _, k := range keys {
+				buf.WriteString(fmt.Sprintf("\n> [%s] %s: %s", reqID, k, strings.Join(r.Header[k], ", ")))
+			}
+
+			// Request parameters
+			params := mux.Vars(r)
+			keys = make([]string, len(params))
+			i = 0
+			for k := range params {
+				keys[i] = k
+				i++
+			}
+			sort.Strings(keys)
+			for _, k := range keys {
+				buf.WriteString(fmt.Sprintf("\n> [%s] %s: %s", reqID, k, params[k]))
+			}
+
+			// Request body
+			b, err := io.ReadAll(r.Body)
+			if err != nil {
+				b = []byte("failed to read body: " + err.Error())
+			}
+			if len(b) > 0 {
+				buf.WriteByte('\n')
+				lines := strings.Split(string(b), "\n")
+				for _, line := range lines {
+					buf.WriteString(fmt.Sprintf("[%s] %s\n", reqID, line))
+				}
+			}
+			r.Body = io.NopCloser(bytes.NewBuffer(b))
+
+			dupper := &responseDupper{ResponseWriter: rw, Buffer: &bytes.Buffer{}}
+			h.ServeHTTP(dupper, r)
+
+			buf.WriteString(fmt.Sprintf("\n< [%s] %s", reqID, http.StatusText(dupper.Status)))
+			keys = make([]string, len(dupper.Header()))
+			printResponseBody := true
+			i = 0
+			for k, v := range dupper.Header() {
+				if k == "Content-Type" && len(v) > 0 && v[0] == "application/x-7z-compressed" {
+					printResponseBody = false
+				}
+				keys[i] = k
+				i++
+			}
+			sort.Strings(keys)
+			for _, k := range keys {
+				buf.WriteString(fmt.Sprintf("\n< [%s] %s: %s", reqID, k, strings.Join(dupper.Header()[k], ", ")))
+			}
+			if printResponseBody {
+				buf.WriteByte('\n')
+				lines := strings.Split(dupper.Buffer.String(), "\n")
+				for _, line := range lines {
+					buf.WriteString(fmt.Sprintf("[%s] %s\n", reqID, line))
+				}
+			}
+			buf.WriteByte('\n')
+			_, err = w.Write(buf.Bytes()) // nolint: errcheck
+			if err != nil {
+				panic(err)
+			}
+		})
+	}
+}
+
+// responseDupper tees the response to a buffer and a response writer.
+type responseDupper struct {
+	http.ResponseWriter
+	Buffer *bytes.Buffer
+	Status int
+}
+
+// Write writes the data to the buffer and connection as part of an HTTP reply.
+func (r *responseDupper) Write(b []byte) (int, error) {
+	return io.MultiWriter(r.ResponseWriter, r.Buffer).Write(b)
+}
+
+// WriteHeader records the status and sends an HTTP response header with status code.
+func (r *responseDupper) WriteHeader(s int) {
+	r.Status = s
+	r.ResponseWriter.WriteHeader(s)
+}
+
+// Hijack supports the http.Hijacker interface.
+func (r *responseDupper) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	if hijacker, ok := r.ResponseWriter.(http.Hijacker); ok {
+		return hijacker.Hijack()
+	}
+	return nil, nil, fmt.Errorf("debug middleware: inner ResponseWriter cannot be hijacked: %T", r.ResponseWriter)
+}
+
+// shortID produces a " unique" 6 bytes long string.
+// Do not use as a reliable way to get unique IDs, instead use for things like logging.
+func shortID() string {
+	b := make([]byte, 6)
+	io.ReadFull(rand.Reader, b) // nolint: errcheck
+	return base64.RawURLEncoding.EncodeToString(b)
+}