From: Dan Fuhry <dan@fuhry.com>
Date: Wed, 6 Aug 2025 03:22:56 +0000 (-0400)
Subject: [http] add request IDs w/tracing support
X-Git-Url: https://go.fuhry.dev/?a=commitdiff_plain;h=abc5ec7b9f6ecff22224a6adc72292d23a982173;p=runtime.git

[http] add request IDs w/tracing support
---

diff --git a/http/server.go b/http/server.go
index e056d28..b845776 100644
--- a/http/server.go
+++ b/http/server.go
@@ -3,13 +3,16 @@ package http
 import (
 	"context"
 	"crypto/tls"
+	"encoding/hex"
 	"errors"
 	"fmt"
+	"math/rand"
 	"net"
 	"net/http"
 	"os"
 	"regexp"
 	"sync"
+	"time"
 
 	"go.fuhry.dev/runtime/mtls"
 	"go.fuhry.dev/runtime/utils/log"
@@ -33,11 +36,12 @@ type VirtualHost struct {
 }
 
 type Listener struct {
-	Addr          string                  `yaml:"listen"`
-	ProxyProtocol bool                    `yaml:"proxy_protocol"`
-	InsecureAddr  string                  `yaml:"listen_insecure"`
-	Certificate   string                  `yaml:"cert"`
-	VirtualHosts  map[string]*VirtualHost `yaml:"virtual_hosts"`
+	Addr                   string                  `yaml:"listen"`
+	ProxyProtocol          bool                    `yaml:"proxy_protocol"`
+	InsecureAddr           string                  `yaml:"listen_insecure"`
+	Certificate            string                  `yaml:"cert"`
+	TrustUpstreamRequestID bool                    `yaml:"trust_upstream_request_id"`
+	VirtualHosts           map[string]*VirtualHost `yaml:"virtual_hosts"`
 }
 
 type Server struct {
@@ -56,8 +60,10 @@ const (
 	kListener
 	kListenAddr
 	kSamlDefaults
+	kRequestID
 )
 
+var randSrc = rand.New(rand.NewSource(time.Now().UnixNano()))
 var portSpec = regexp.MustCompile(":[0-9]{1,5}$")
 var initHooks []initHook
 var routeParseFuncs []routeParseFunc
@@ -237,6 +243,7 @@ func (l *Listener) NewHTTPServerWithContext(ctx context.Context) (*http.Server,
 	lm := log.NewLoggingMiddlewareWithLogger(
 		http.HandlerFunc(l.handle),
 		logger.AppendPrefix(".access"))
+	lm.AddResponseHeader("x-request-id")
 
 	server := &http.Server{
 		Addr: l.Addr,
@@ -297,6 +304,14 @@ func (l *Listener) handle(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	reqIdCtx := r.Context()
+	rid := r.Header.Get("x-request-id")
+	if rid == "" || !l.TrustUpstreamRequestID {
+		rid = newRequestID()
+	}
+	w.Header().Set("x-request-id", rid)
+	reqIdCtx = context.WithValue(reqIdCtx, kRequestID, rid)
+
 	// make sure this host is known
 	vhost, ok := l.VirtualHosts[r.Host]
 	if !ok {
@@ -309,7 +324,7 @@ func (l *Listener) handle(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	l.fulfill(w, r, vhost.Routes)
+	l.fulfill(w, r.WithContext(reqIdCtx), vhost.Routes)
 }
 
 func (l *Listener) fulfill(w http.ResponseWriter, r *http.Request, routes []*Route) {
@@ -355,8 +370,18 @@ func (l *Listener) fulfill(w http.ResponseWriter, r *http.Request, routes []*Rou
 func LoggerFromContext(ctx context.Context) log.Logger {
 	l := ctx.Value(kLogger)
 	if logger, ok := l.(log.Logger); ok {
+		if v, ok := ctx.Value(kRequestID).(string); ok {
+			logger = logger.AppendPrefix(fmt.Sprintf("<id=%s>", v))
+		}
 		return logger
 	}
 
 	return nil
 }
+
+func newRequestID() string {
+	buf := make([]byte, 10)
+	_, _ = randSrc.Read(buf)
+
+	return hex.EncodeToString(buf)
+}