User Agent:

- Now sends user agent with gateway requests
- git based version is embedded in binary for UA and logs
- configurable string to put in UA for big servers
Fixes #32

Makefile

@@ -2,7 +2,7 @@ BUILD_DIR=./bin
 DOCKER_CMD=docker run --rm -it -v "$$PWD":/usr/src/myapp -w /usr/src/myapp golang:1.17
 
 local:
-	go build -o up-rewrite
+	GIT_CMT=$$(git describe --tags) && go build -o up-rewrite -ldflags "-X github.com/karmanyaahm/up_rewrite/config.Version=$$GIT_CMT"
 local-docker:
 	$(DOCKER_CMD) make local
 all:

config/config.go

@@ -16,12 +16,15 @@ import (
 	"github.com/komkom/toml"
 )
 
+var Version string = "dev"
+
 var Config Configuration
 var ConfigLock sync.RWMutex
 
 type Configuration struct {
-	ListenAddr string `env:"UP_LISTEN"`
-	Verbose    bool   `env:"UP_VERBOSE"`
+	ListenAddr  string `env:"UP_LISTEN"`
+	Verbose     bool   `env:"UP_VERBOSE"`
+	UserAgentID string `env:"UP_UAID"`
 
 	Gateway struct {
 		AllowedHosts []string `env:"UP_GATEWAY_ALLOWEDHOSTS"`
@@ -34,6 +37,19 @@ type Configuration struct {
 	}
 }
 
+var ua string
+
+func (c Configuration) GetUserAgent() string {
+	if ua != "" {
+		return ua
+	}
+	ua = "UnifiedPush-Common-Proxies/" + Version
+	if Config.UserAgentID != "" {
+		ua += " (" + Config.UserAgentID + ")"
+	}
+	return ua
+}
+
 func ParseConf(location string) error {
 	ConfigLock.Lock()
 	defer ConfigLock.Unlock()

handler.go

@@ -71,6 +71,8 @@ func gatewayHandler(h Gateway) HttpHandler {
 			resps := make([]*http.Response, len(reqs))
 			for i, req := range reqs {
 				nwritten += req.ContentLength
+
+				req.Header.Add("User-Agent", Config.GetUserAgent())
 				if utils.InStringSlice(config.Config.Gateway.AllowedHosts, req.URL.Host) {
 					CheckIfRewriteProxy(req.URL.String(), normalClient)
 					resps[i], err = normalClient.Do(req)

main.go

@@ -27,6 +27,8 @@ func main() {
 		log.Fatalln(err)
 	}
 
+	log.Println("Starting", Config.GetUserAgent())
+
 	handlers = []Handler{
 		&Config.Rewrite.Gotify,
 		&Config.Rewrite.FCM,