Implement sighandler, logfile can be not only stderr

* Implement sighandler for int, quit, term signals
* Implement log reopen on sighup
* Catch http.Server's error log
* Implement logfile setting in config

.golangci.yml

@@ -1,6 +1,6 @@
 version: "2"
 run:
-  go: "1.25"
+  go: "1.24"
   modules-download-mode: readonly
   tests: false
   allow-parallel-runners: true
@@ -196,7 +196,51 @@ linters:
         - fmt
       # https://staticcheck.dev/docs/configuration/options/#initialisms
       # Default: ["ACL", "API", "ASCII", "CPU", "CSS", "DNS", "EOF", "GUID", "HTML", "HTTP", "HTTPS", "ID", "IP", "JSON", "QPS", "RAM", "RPC", "SLA", "SMTP", "SQL", "SSH", "TCP", "TLS", "TTL", "UDP", "UI", "GID", "UID", "UUID", "URI", "URL", "UTF8", "VM", "XML", "XMPP", "XSRF", "XSS", "SIP", "RTP", "AMQP", "DB", "TS"]
-      initialisms: ["ACL", "API", "ASCII", "CPU", "CSS", "DNS", "EOF", "GUID", "HTML", "HTTP", "HTTPS", "ID", "IP", "JSON", "QPS", "RAM", "RPC", "SLA", "SMTP", "SQL", "SSH", "TCP", "TLS", "TTL", "UDP", "UI", "GID", "UID", "UUID", "URI", "URL", "UTF8", "VM", "XML", "XMPP", "XSRF", "XSS", "SIP", "RTP", "AMQP", "DB", "TS"]
+      initialisms:
+        [
+          "ACL",
+          "API",
+          "ASCII",
+          "CPU",
+          "CSS",
+          "DNS",
+          "EOF",
+          "GUID",
+          "HTML",
+          "HTTP",
+          "HTTPS",
+          "ID",
+          "IP",
+          "JSON",
+          "QPS",
+          "RAM",
+          "RPC",
+          "SLA",
+          "SMTP",
+          "SQL",
+          "SSH",
+          "TCP",
+          "TLS",
+          "TTL",
+          "UDP",
+          "UI",
+          "GID",
+          "UID",
+          "UUID",
+          "URI",
+          "URL",
+          "UTF8",
+          "VM",
+          "XML",
+          "XMPP",
+          "XSRF",
+          "XSS",
+          "SIP",
+          "RTP",
+          "AMQP",
+          "DB",
+          "TS",
+        ]
       # https://staticcheck.dev/docs/configuration/options/#http_status_code_whitelist
       # Default: ["200", "400", "404", "500"]
       http-status-code-whitelist: ["200", "400", "404", "500"]

cmd/joyproxy/main.go

@@ -2,8 +2,11 @@
 package main
 
 import (
+	"errors"
 	"net/http"
 	"os"
+	"os/signal"
+	"syscall"
 	"time"
 
 	"joyproxy/internal/joyproxy"
@@ -12,26 +15,74 @@ import (
 
 // main application entry point.
 func main() {
+	var (
+		err     error
+		logfile *os.File
+	)
+
 	joyproxy.LoadConf()
 
-	log.Init(joyproxy.Cfg.Loglevel, os.Stderr)
+	if joyproxy.Cfg.Logfile != "" {
+		logfile, err = os.OpenFile(joyproxy.Cfg.Logfile, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0644)
 
+		if err != nil {
+			log.Fatalf("Unable to open %s: %s", joyproxy.Cfg.Logfile, err)
+		}
+	} else {
+		logfile = os.Stderr
+	}
+
+	log.Init(joyproxy.Cfg.Loglevel, logfile)
+
+	log.Info("Install handler to /joyproxy/ location")
 	http.HandleFunc("/joyproxy/", joyproxy.JoyproxyHandler)
+
+	log.Info("Install handler to /joyurl location")
 	http.HandleFunc("/joyurl", joyproxy.JoyurlHandler)
 
-	log.Infof("Starting application on port %v\n", joyproxy.Cfg.Port)
+	// It's time to set up signal trapper.
+	signal.Notify(joyproxy.SigChan,
+		syscall.SIGINT,
+		syscall.SIGTERM,
+		syscall.SIGQUIT,
+		syscall.SIGHUP,
+	)
+
+	go joyproxy.SigHandler()
+
+	log.Infof("Listening on port %v\n", joyproxy.Cfg.Port)
 
 	// To prevent slow loris ddos, we have to define custom handler because builtin http.ListenAndServe() have no
 	// timeout and sits here forever.
-	server := &http.Server{
+	joyproxy.Server = &http.Server{
 		Addr:              joyproxy.Cfg.Port,
 		ReadHeaderTimeout: time.Duration(joyproxy.Cfg.Timeout) * time.Second,
 		ReadTimeout:       time.Duration(joyproxy.Cfg.Timeout) * time.Second,
 		WriteTimeout:      time.Duration(joyproxy.Cfg.Timeout) * time.Second,
 		IdleTimeout:       time.Duration(joyproxy.Cfg.Timeout) * time.Second,
+		ErrorLog:          &log.Logger,
 	}
 
-	log.Warn(server.ListenAndServe().Error())
+	for {
+		if joyproxy.Shutdown {
+			time.Sleep(100 * time.Microsecond)
+
+			continue
+		}
+
+		err = joyproxy.Server.ListenAndServe()
+
+		if errors.Is(err, http.ErrServerClosed) {
+			log.Info("Shutdown joyproxy")
+
+			break
+		}
+
+		log.Errorf("Listener error: %s", err)
+	}
+
+	<-joyproxy.QuitChan
+	os.Exit(0)
 }
 
 /* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

internal/joyproxy/globals.go

@@ -1,6 +1,11 @@
 // Package joyproxy is main appliction lib.
 package joyproxy
 
+import (
+	"net/http"
+	"os"
+)
+
 var (
 	// Cfg represents struct with application config settings.
 	Cfg Config
@@ -42,6 +47,18 @@ var (
 	}
 
 	postForm = "<html>\n<body>\n<form method='get' action='joyurl'>\n<input type='text' name='joyurl' size=100 autofocus><br>\n<input type='submit' value='Post it!' style='font-size:115%%;'>\n<br>%s<br>\n</body>\n</html>\n"
+
+	// SigChan is channel for signal handler routine SigHandler().
+	SigChan = make(chan os.Signal, 1)
+
+	// Server represents http server object.
+	Server *http.Server
+
+	// Shutdown set to true if service is shutting down via SigHandler().
+	Shutdown bool
+
+	// QuitChan is locking mechanism to wait until shutdown procedure completes.
+	QuitChan = make(chan bool, 1)
 )
 
 /* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

internal/joyproxy/joyproxyHandler.go

@@ -14,12 +14,13 @@ import (
 	"github.com/davecgh/go-spew/spew"
 )
 
-// JoyproxyHandler request handler for /joyproxy location.
+// JoyproxyHandler request handler for /joyproxy location. It reads data from reactor.cc and immediately streams it to
+// client.
 func JoyproxyHandler(w http.ResponseWriter, r *http.Request) { //nolint: revive
 	var err error
 
 	if r.Method != http.MethodGet {
-		log.Infof("request method is not GET, but %s", r.Method)
+		log.Infof("Request method is not GET, but %s, sending 404 to client", r.Method)
 		w.WriteHeader(http.StatusNotFound)
 
 		if _, err = w.Write([]byte("404 Not Found")); err != nil {
@@ -35,7 +36,7 @@ func JoyproxyHandler(w http.ResponseWriter, r *http.Request) { //nolint: revive
 	joyHost := joyPath[2]
 
 	if !regexp.MustCompile("^img[0-9]+[.]reactor[.]cc$").MatchString(joyHost) {
-		log.Infof("supplied proxy target host is not match with ^img[0-9]+[.]reactor[.]cc$ pattern: %s", joyHost)
+		log.Infof("Supplied proxy target host is not match with ^img[0-9]+[.]reactor[.]cc$ pattern: %s, sening 404 to client", joyHost)
 		w.WriteHeader(http.StatusNotFound)
 
 		if _, err = w.Write([]byte("404 Not Found")); err != nil {
@@ -49,7 +50,7 @@ func JoyproxyHandler(w http.ResponseWriter, r *http.Request) { //nolint: revive
 	dlReq.RequestURI = "/" + strings.Join(joyPath, "/")
 
 	if !regexp.MustCompile("^/pics/post/mp4/.+[.]mp4$").MatchString(dlReq.RequestURI) {
-		log.Infof("supplied uri is not match with /pics/post/mp4/.+[.]mp4$ pattern: %s", dlReq.RequestURI)
+		log.Infof("Supplied uri is not match with /pics/post/mp4/.+[.]mp4$ pattern: %s, sending 404 to client", dlReq.RequestURI)
 		w.WriteHeader(http.StatusNotFound)
 
 		if _, err = w.Write([]byte("404 Not Found")); err != nil {
@@ -63,7 +64,7 @@ func JoyproxyHandler(w http.ResponseWriter, r *http.Request) { //nolint: revive
 	dlReq.URL, err = url.Parse(dlReq.RequestURI)
 
 	if err != nil {
-		log.Infof("unable to parse %s via url.Parse(): %s", dlReq.RequestURI, err)
+		log.Infof("Unable to parse %s via url.Parse(): %s, sending 404 to client", dlReq.RequestURI, err)
 		w.WriteHeader(http.StatusNotFound)
 
 		if _, err = w.Write([]byte("404 Not Found")); err != nil {
@@ -78,13 +79,16 @@ func JoyproxyHandler(w http.ResponseWriter, r *http.Request) { //nolint: revive
 		dlReq.Header.Del("Referer")
 	}
 
+	log.Debugf("Replacing/appending Referer header value with https://old.reactor.cc/all")
 	dlReq.Header.Add("Referer", "https://old.reactor.cc/all")
 
 	if dlReq.Header.Get("User-Agent") != "" {
 		dlReq.Header.Del("User-Agent")
 	}
 
-	dlReq.Header.Add("User-Agent", userAgentString[rand.Intn(len(userAgentString)-1)])
+	ua := userAgentString[rand.Intn(len(userAgentString)-1)]
+	log.Debugf("Replacing User-Agent header value with %s", ua)
+	dlReq.Header.Add("User-Agent", ua)
 
 	if dlReq.Header.Get("Accept") != "" {
 		dlReq.Header.Del("Accept")
@@ -108,6 +112,7 @@ func JoyproxyHandler(w http.ResponseWriter, r *http.Request) { //nolint: revive
 		dlReq.Header.Del("Range")
 	}
 
+	log.Debugf("Replacing/appending Range header value with bytes=0-")
 	dlReq.Header.Add("Range", "bytes=0-")
 	log.Debug(spew.Sdump(dlReq))
 
@@ -115,7 +120,7 @@ func JoyproxyHandler(w http.ResponseWriter, r *http.Request) { //nolint: revive
 	target, err := url.Parse(u)
 
 	if err != nil {
-		log.Infof("unable to parse %s via url.Parse(): %s", u, err)
+		log.Infof("Unable to parse %s via url.Parse(): %s, sending 404 to client", u, err)
 		w.WriteHeader(http.StatusNotFound)
 
 		if _, err = w.Write([]byte("404 Not Found")); err != nil {
@@ -133,7 +138,10 @@ func JoyproxyHandler(w http.ResponseWriter, r *http.Request) { //nolint: revive
 			KeepAlive: time.Duration(Cfg.Timeout) * time.Second,
 		}).Dial,
 		TLSHandshakeTimeout: time.Duration(Cfg.Timeout) * time.Second,
+		DisableKeepAlives:   true,
+		DisableCompression:  true,
 	}
+
 	joyproxy.ServeHTTP(w, dlReq)
 }
 

internal/joyproxy/joyurlHandler.go

@@ -18,19 +18,19 @@ func JoyurlHandler(w http.ResponseWriter, r *http.Request) {
 		proxyURLString = " "
 	)
 
-	log.Debug(spew.Sdump(param))
+	log.Debugf("Parse url into chunks: %s", spew.Sdump(param))
 
 	re := regexp.MustCompile("^https?://img[0-9]+[.]reactor[.]cc/.+[.][Ww][Ee][Bb][Mm]$")
 
 	if len(param) > 0 && re.MatchString(param["joyurl"][0]) {
-		log.Debug("match with ^https?://img[0-9]+[.]reactor[.]cc/.+[.][Ww][Ee][Bb][Mm]$ pattern")
+		log.Debug("Url match with ^https?://img[0-9]+[.]reactor[.]cc/.+[.][Ww][Ee][Bb][Mm]$ pattern")
 		// https://img1.reactor.cc/pics/post/webm/видосик.webm
 
 		p := regexp.MustCompile("/").Split(param["joyurl"][0], -1)
-		log.Debug(spew.Sdump(p))
+		log.Debugf("Split url string by / delimiter: %s", spew.Sdump(p))
 
 		if len(p) > 6 && p[5] == "webm" {
-			log.Debug("webm url part detected, let's make joyproxy url")
+			log.Debug("Substring webm is detected in url, let's make joyproxy url")
 
 			file := p[6][:len(p[6])-5]
 
@@ -46,10 +46,10 @@ func JoyurlHandler(w http.ResponseWriter, r *http.Request) {
 
 			proxyURLString = html.EscapeString(proxyURLString)
 		} else {
-			log.Debug("webm url part not detected, skip making joyproxy url")
+			log.Debug("Substring webm not detected in url, skip making joyproxy url")
 		}
 	} else {
-		log.Info("not match with ^https?://img[0-9]+[.]reactor[.]cc/.+[.][Ww][Ee][Bb][Mm]$ regex")
+		log.Info("Url is not match with ^https?://img[0-9]+[.]reactor[.]cc/.+[.][Ww][Ee][Bb][Mm]$ regex, skipping")
 	}
 
 	htmlText := fmt.Sprintf(postForm, proxyURLString)

internal/joyproxy/loadConf.go

@@ -52,6 +52,12 @@ func LoadConf() {
 	if Cfg.Loglevel == "" {
 		log.Fatalf("unable to get loglevel setting from settings section of %s", configINIPath)
 	}
+
+	Cfg.Logfile = configFH.Section("settings").Get("logfile")
+
+	if Cfg.Logfile == "" {
+		log.Infof("Logfile parameter is not set in settings section of %s", configINIPath)
+	}
 }
 
 /* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

internal/joyproxy/sigHandler.go

@@ -0,0 +1,44 @@
+package joyproxy
+
+import (
+	"joyproxy/internal/log"
+	"syscall"
+)
+
+// SigHandler handles signals from OS.
+func SigHandler() {
+	for {
+		var s = <-SigChan
+		switch s {
+		case syscall.SIGINT:
+			log.Info("Got SIGINT, quitting")
+		case syscall.SIGTERM:
+			log.Info("Got SIGTERM, quitting")
+		case syscall.SIGQUIT:
+			log.Info("Got SIGQUIT, quitting")
+		case syscall.SIGHUP:
+			log.Info("Got SIGHUP, reopening logs")
+			log.ReOpenLog()
+
+			continue
+
+		// Make new iteration since we 've got signal we not interested in.
+		default:
+			continue
+		}
+
+		Shutdown = true
+
+		if err := Server.Close(); err != nil {
+			log.Errorf("Unable to close server: %s", err.Error())
+		}
+
+		log.Close()
+
+		QuitChan <- true
+
+		break
+	}
+}
+
+/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

internal/joyproxy/types.go

@@ -6,6 +6,7 @@ type (
 		Port     string
 		Proto    string
 		Loglevel string
+		Logfile  string
 		Timeout  int
 	}
 )

internal/log/log.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log"
 	"log/slog"
 	"os"
 	"time"
@@ -24,30 +25,39 @@ var (
 
 	// reader is required for Writer to work properly. It is connected via io.Pipe() to Writer.
 	reader io.Reader
+
+	// Logger *log.Logger thing required for compatibility with old-good log package.
+	Logger log.Logger
+
+	// LogFileHandler is currently opened log file descriptor. Stderr by default.
+	LogFileHandler = os.Stderr
+
+	// LogLevel current loglevel. Info by default.
+	LogLevel = slog.LevelInfo
 )
 
 // Init setup logger stuff.
 // level can be error, warn, info, debug if something other supplied info level selected.
 // fileDescriptor should be opened before supplying it to Init().
 func Init(level string, fileDescriptor *os.File) {
-	var loglevel slog.Level
+	LogFileHandler = fileDescriptor
 
 	// no panic, no trace.
 	switch level {
 	case "debug":
-		loglevel = slog.LevelDebug
+		LogLevel = slog.LevelDebug
 
 	case "info":
-		loglevel = slog.LevelInfo
+		LogLevel = slog.LevelInfo
 
 	case "warn":
-		loglevel = slog.LevelWarn
+		LogLevel = slog.LevelWarn
 
 	case "error":
-		loglevel = slog.LevelError
+		LogLevel = slog.LevelError
 
 	default:
-		loglevel = slog.LevelInfo
+		LogLevel = slog.LevelInfo
 	}
 
 	opts := &slog.HandlerOptions{ //nolint: exhaustruct
@@ -68,15 +78,22 @@ func Init(level string, fileDescriptor *os.File) {
 			return a
 		},
 
-		Level: loglevel,
+		Level: LogLevel,
 	}
 
-	Handler = slog.NewTextHandler(fileDescriptor, opts)
+	// Documentation says that we can use *os.File in place of io.Writer, but in this case it did not work.
+	// So we have to cast fileDescriptor to io.Writer.
+	w := io.Writer(fileDescriptor)
+
+	Handler = slog.NewTextHandler(w, opts)
 
 	slog.SetDefault(
 		slog.New(Handler),
 	)
 
+	// Catch log.Logger message at info loglevel of slog logging facility.
+	Logger = *slog.NewLogLogger(Handler, slog.LevelError)
+
 	reader, Writer = io.Pipe()
 
 	go readIoPipe()
@@ -104,7 +121,7 @@ func readIoPipe() {
 	}
 }
 
-// GetLevel returns current loglevel.
+// GetLevel returns current loglevel as string.
 func GetLevel() string {
 	switch {
 	case Handler.Enabled(Ctx, slog.LevelDebug):
@@ -176,4 +193,40 @@ func Debugf(format string, a ...any) {
 	slog.Debug(fmt.Sprintf(format, a...))
 }
 
+// Close closes opened log file descriptors.
+func Close() {
+	LogFileHandler.Close()
+}
+
+// ReOpenLog closes and opens log file again.
+func ReOpenLog() {
+	filename := LogFileHandler.Name()
+
+	// If we writing to stderr, we should not re-open it.
+	if filename == os.Stderr.Name() {
+		return
+	}
+
+	loglevel := GetLevel()
+
+	LogFileHandler.Close()
+
+	file, err := os.OpenFile(filename, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
+
+	if err != nil {
+		// Try to emulate our own log message format.
+		fmt.Fprintf(
+			os.Stderr,
+			"time=\"%s\" level=ERROR msg=\"Unable to open logfile %s: %s\"",
+			time.Now().Format(time.DateTime),
+			filename,
+			err,
+		)
+
+		return
+	}
+
+	Init(loglevel, file)
+}
+
 /* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

joyproxy_sample.ini

@@ -9,4 +9,7 @@ port = 9980
 timeout = 5
 
 ; loglevel - info or debug, info is what you want
-loglevel = debug
+loglevel = info
+
+; logfile - log to this file, default stderr
+;logfile = /var/log/joyproxy.log