README.md

@@ -19,8 +19,8 @@ Memory usage sits at around 25M under load.
 3. Edit the config.
 4. Start the loadbalancer with `./proxy-loadbalancer --config [path to your config.yml]`
 
-The load balancer has experimental support for using [curl-impersonate](https://github.com/lwthiker/curl-impersonate) to masquerade as the Chrome browser when
+The load balancer supports using [curl-impersonate](https://github.com/lwthiker/curl-impersonate) to masquerade as the
-performing proxy checks.
+Chrome browser when performing proxy checks. This is experimental.
 
 1. Download `*.x86_64-linux-gnu.tar.gz ` from https://github.com/lwthiker/curl-impersonate/releases
 2. Set `proxy_check_impersonate_chrome: true`
@@ -35,19 +35,15 @@ An example systemd service `loadbalancer.service` is provided.
 
 The server displays health, stats, info at `/json`.
 
-Use `--log-third-party-test-failures` along with `--debug` when you want extra info on the third-party proxy tests. This
-can get very noisy if you have lots of third-party proxies so it's hidden behind an extra flag.
-
 ```
 === Proxy Load Balancer ===
-Usage of /tmp/go-build1714785557/b001/exe/proxy-loadbalancer:
+Usage of ./proxy-loadbalancer:
   --config [string]
-        Path to the config file
+               Path to the config file
-  -d, --debug
+  -d, --debug  
-        Enable debug mode
+               Enable debug mode
-  -l, --log-third-party-test-failures
+  --v          Print version and exit
-        Log third-party test debug info
+  -h, --help   Print this help message
-  -v    Print version and exit
 ```
 
 ## Special Headers

config.example.yml

@@ -13,10 +13,6 @@ ip_checker_url:                        https://api.ipify.org
 # Connection timeout for the proxies in seconds.
 proxy_connect_timeout:                 60
 
-# How many times to retry a proxy connection.
-# On each retry a new proxy will be chosen.
-proxy_connect_retries:                   3
-
 # Use `curl-impersonate` to pretend to be Chrome when testing proxies.
 proxy_check_impersonate_chrome:        false
 proxy_check_impersonate_chrome_binary: ./curl_chrome116

src/config/config.go

@@ -27,7 +27,6 @@ type Config struct {
 	ProxyCheckInterval                int
 	ProxyCheckImpersonateChrome       bool
 	ProxyCheckImpersonateChromeBinary string
-	ProxyConnectRetries               int
 }
 
 func SetConfig(configFile string) (*Config, error) {
@@ -50,7 +49,6 @@ func SetConfig(configFile string) (*Config, error) {
 	viper.SetDefault("proxy_check_interval", 60)
 	viper.SetDefault("proxy_check_impersonate_chrome", false)
 	viper.SetDefault("proxy_check_impersonate_chrome_binary", nil)
-	viper.SetDefault("proxy_connect_retries", 3)
 
 	err := viper.ReadInConfig()
 	if err != nil {
@@ -71,7 +69,6 @@ func SetConfig(configFile string) (*Config, error) {
 		ProxyCheckInterval:                viper.GetInt("proxy_check_interval"),
 		ProxyCheckImpersonateChrome:       viper.GetBool("proxy_check_impersonate_chrome"),
 		ProxyCheckImpersonateChromeBinary: viper.GetString("proxy_check_impersonate_chrome_binary"),
-		ProxyConnectRetries:               viper.GetInt("proxy_connect_retries"),
 	}
 
 	if len(config.ProxyPoolOurs) == 0 && len(config.ProxyPoolThirdparty) == 0 {
@@ -98,19 +95,13 @@ func SetConfig(configFile string) (*Config, error) {
 		return nil, proxyPoolThirdpartyErr
 	}
 
-	if config.ProxyCheckImpersonateChrome {
+	if _, err := os.Stat(config.ProxyCheckImpersonateChromeBinary); os.IsNotExist(err) {
-		if _, err := os.Stat(config.ProxyCheckImpersonateChromeBinary); os.IsNotExist(err) {
+		return nil, errors.New(fmt.Sprintf(`curl-impersonate-chrome binary does not exist: "%s"`, config.ProxyCheckImpersonateChromeBinary))
-			return nil, errors.New(fmt.Sprintf(`curl-impersonate-chrome binary does not exist: "%s"`, config.ProxyCheckImpersonateChromeBinary))
-		}
-		cmd := exec.Command(config.ProxyCheckImpersonateChromeBinary, "--help")
-		err = cmd.Run()
-		if err != nil {
-			return nil, errors.New(fmt.Sprintf(`curl-impersonate-chrome binary failed to run: %s`, err))
-		}
 	}
-
+	cmd := exec.Command(config.ProxyCheckImpersonateChromeBinary, "--help")
-	if config.ProxyConnectRetries <= 0 {
+	err = cmd.Run()
-		return nil, errors.New("proxy_connect_retries must be greater than 0")
+	if err != nil {
+		return nil, errors.New(fmt.Sprintf(`curl-impersonate-chrome binary failed to run: %s`, err))
 	}
 
 	cfg = config

src/config/flags.go

@@ -1,27 +0,0 @@
-package config
-
-import "flag"
-
-var CliArgs *CliConfig
-
-type CliConfig struct {
-	ConfigFile        string
-	Debug             bool
-	Help              bool
-	Version           bool
-	LogThirdPartyTest bool
-}
-
-func ParseArgs() {
-	if CliArgs != nil {
-		panic("already defined")
-	}
-	CliArgs = &CliConfig{}
-	flag.StringVar(&CliArgs.ConfigFile, "config", "", "Path to the config file")
-	flag.BoolVar(&CliArgs.Debug, "d", false, "Enable debug mode")
-	flag.BoolVar(&CliArgs.Debug, "debug", false, "Enable debug mode")
-	flag.BoolVar(&CliArgs.Debug, "l", false, "Log third-party test debug info")
-	flag.BoolVar(&CliArgs.Debug, "log-third-party-test-failures", false, "Log third-party test debug info")
-	flag.BoolVar(&CliArgs.Version, "v", false, "Print version and exit")
-	flag.Parse()
-}

src/proxy-loadbalancer.go

@@ -13,17 +13,26 @@ import (
 	"runtime/debug"
 )
 
+type cliConfig struct {
+	configFile         string
+	initialCrawl       bool
+	debug              bool
+	disableElasticSync bool
+	help               bool
+	version            bool
+}
+
 var Version = "development"
 var VersionDate = "not set"
 
 func main() {
 	fmt.Println("=== Proxy Load Balancer ===")
-	config.ParseArgs()
+	cliArgs := parseArgs()
-	if config.CliArgs.Help {
+	if cliArgs.help {
 		flag.Usage()
 		os.Exit(0)
 	}
-	if config.CliArgs.Version {
+	if cliArgs.version {
 		buildInfo, ok := debug.ReadBuildInfo()
 
 		if ok {
@@ -42,7 +51,7 @@ func main() {
 		os.Exit(0)
 	}
 
-	if config.CliArgs.Debug {
+	if cliArgs.debug {
 		logging.InitLogger(logrus.DebugLevel)
 	} else {
 		logging.InitLogger(logrus.InfoLevel)
@@ -50,7 +59,7 @@ func main() {
 	log := logging.GetLogger()
 	log.Debugln("Initializing...")
 
-	if config.CliArgs.ConfigFile == "" {
+	if cliArgs.configFile == "" {
 		exePath, err := os.Executable()
 		if err != nil {
 			panic(err)
@@ -61,23 +70,20 @@ func main() {
 			if _, err := os.Stat(filepath.Join(exeDir, "config.yaml")); err == nil {
 				log.Fatalln("Both config.yml and config.yaml exist in the executable directory. Please specify one with the --config flag.")
 			}
-			config.CliArgs.ConfigFile = filepath.Join(exeDir, "config.yml")
+			cliArgs.configFile = filepath.Join(exeDir, "config.yml")
 		} else if _, err := os.Stat(filepath.Join(exeDir, "config.yaml")); err == nil {
-			config.CliArgs.ConfigFile = filepath.Join(exeDir, "config.yaml")
+			cliArgs.configFile = filepath.Join(exeDir, "config.yaml")
 		} else {
 			log.Fatalln("No config file found in the executable directory. Please provide one with the --config flag.")
 		}
 	}
-	configData, err := config.SetConfig(config.CliArgs.ConfigFile)
+	configData, err := config.SetConfig(cliArgs.configFile)
 	if err != nil {
 		log.Fatalf(`Failed to load config: %s`, err)
 	}
 
 	log.Debugf(`Proxy check interval: %d sec`, config.GetConfig().ProxyCheckInterval)
-
+	log.Debugf(`Using curl-impersonate binary: %s`, config.GetConfig().ProxyCheckImpersonateChromeBinary)
-	if config.GetConfig().ProxyCheckImpersonateChrome {
-		log.Debugf(`Using curl-impersonate binary: %s`, config.GetConfig().ProxyCheckImpersonateChromeBinary)
-	}
 
 	proxyCluster := proxy.NewForwardProxyCluster()
 	go func() {
@@ -91,3 +97,13 @@ func main() {
 
 	select {}
 }
+
+func parseArgs() cliConfig {
+	var cliArgs cliConfig
+	flag.StringVar(&cliArgs.configFile, "config", "", "Path to the config file")
+	flag.BoolVar(&cliArgs.debug, "d", false, "Enable debug mode")
+	flag.BoolVar(&cliArgs.debug, "debug", false, "Enable debug mode")
+	flag.BoolVar(&cliArgs.version, "v", false, "Print version and exit")
+	flag.Parse()
+	return cliArgs
+}

src/proxy/handleConnect.go

@@ -97,6 +97,7 @@ func (p *ForwardProxyCluster) proxyHttpConnect(w http.ResponseWriter, req *http.
 	remoteAddr, _, _ := net.SplitHostPort(req.RemoteAddr)
 	_, proxyUser, proxyPass, proxyHost, parsedProxyUrl, err := p.validateRequestAndGetProxy(w, req)
 	if err != nil {
+		// Error has already been handled, just log and return.
 		if proxyHost == "" {
 			proxyHost = "none"
 		}
@@ -104,6 +105,7 @@ func (p *ForwardProxyCluster) proxyHttpConnect(w http.ResponseWriter, req *http.
 		return
 	}
 
+	// Variables for later
 	var returnCode *int
 	returnCode = new(int)
 	*returnCode = -1
@@ -133,25 +135,18 @@ func (p *ForwardProxyCluster) proxyHttpConnect(w http.ResponseWriter, req *http.
 	copyHeader(proxyReq.Header, req.Header)
 	proxyReq.Header.Set("X-Forwarded-For", req.RemoteAddr)
 
-	for i := 0; i < config.GetConfig().ProxyConnectRetries; i++ { // Retry mechanic
+	resp, err := client.Do(proxyReq)
-		resp, err := client.Do(proxyReq)
+	if err != nil {
-		if err != nil {
+		*errorMsg = fmt.Sprintf(`Failed to execute %s request to "%s": %s`, req.Method, req.URL.String(), err)
-			*errorMsg = fmt.Sprintf(`Failed to execute %s request to "%s" - attempt %d/%d - %s`, req.Method, req.URL.String(), i+1, config.GetConfig().ProxyConnectRetries, err)
+		http.Error(w, "failed to execute request to downstream", http.StatusServiceUnavailable)
-			if i < config.GetConfig().ProxyConnectRetries-1 {
+		return
-				continue
-			} else {
-				http.Error(w, "failed to execute request to downstream", http.StatusServiceUnavailable)
-				return
-			}
-		} else {
-			defer resp.Body.Close()
-			*returnCode = resp.StatusCode
-			copyHeader(w.Header(), resp.Header)
-			w.WriteHeader(resp.StatusCode)
-			io.Copy(w, resp.Body)
-			break
-		}
 	}
+	defer resp.Body.Close()
+	*returnCode = resp.StatusCode
+
+	copyHeader(w.Header(), resp.Header)
+	w.WriteHeader(resp.StatusCode)
+	io.Copy(w, resp.Body)
 }
 
 func (p *ForwardProxyCluster) proxyHttpsConnect(w http.ResponseWriter, req *http.Request) {
@@ -160,6 +155,7 @@ func (p *ForwardProxyCluster) proxyHttpsConnect(w http.ResponseWriter, req *http
 	targetHost, _, _ := net.SplitHostPort(req.Host)
 	_, proxyUser, proxyPass, proxyHost, _, err := p.validateRequestAndGetProxy(w, req)
 	if err != nil {
+		// Error has already been handled, just log and return.
 		if proxyHost == "" {
 			proxyHost = "none"
 		}
@@ -174,21 +170,12 @@ func (p *ForwardProxyCluster) proxyHttpsConnect(w http.ResponseWriter, req *http
 	*errorMsg = ""
 	defer logProxyRequest(remoteAddr, proxyHost, targetHost, returnCode, "CONNECT", requestStartTime, errorMsg)
 
-	var proxyConn net.Conn
+	// Start a connection to the downstream proxy server.
-	for i := 0; i < config.GetConfig().ProxyConnectRetries; i++ {
+	proxyConn, err := net.DialTimeout("tcp", proxyHost, config.GetConfig().ProxyConnectTimeout)
-		// Start a connection to the downstream proxy server.
+	if err != nil {
-		proxyConn, err = net.DialTimeout("tcp", proxyHost, config.GetConfig().ProxyConnectTimeout)
+		*errorMsg = fmt.Sprintf(`Failed to dial proxy %s - %s`, proxyHost, err)
-		if err != nil {
+		http.Error(w, "failed to make request to downstream", http.StatusServiceUnavailable)
-			*errorMsg = fmt.Sprintf(`Failed to dial proxy %s - attempt %d/%d - %s`, proxyHost, i+1, config.GetConfig().ProxyConnectRetries, err)
+		return
-			if i < config.GetConfig().ProxyConnectRetries-1 {
-				continue
-			} else {
-				http.Error(w, "failed to make request to downstream", http.StatusServiceUnavailable)
-				return
-			}
-		} else {
-			break
-		}
 	}
 
 	// Proxy authentication

src/proxy/threads.go

@@ -10,8 +10,6 @@ import (
 	"time"
 )
 
-// TODO: fix 503 errors returned during proxy checking process
-
 func (p *ForwardProxyCluster) ValidateProxiesThread() {
 	log.Infoln("Doing initial backend check, please wait...")
 	started := false
@@ -60,13 +58,10 @@ func (p *ForwardProxyCluster) ValidateProxiesThread() {
 				// Test the proxy.
 				ipAddr, testErr := sendRequestThroughProxy(pxy, config.GetConfig().IpCheckerURL)
 				if testErr != nil {
+					log.Debugf("Validate - %s failed: %s", proxyHost, testErr)
 					if isThirdparty(pxy) {
-						if config.CliArgs.LogThirdPartyTest {
-							log.Debugf("Validate - %s failed: %s", proxyHost, testErr)
-						}
 						newThirdpartyOfflineProxies = append(newThirdpartyOfflineProxies, pxy)
 					} else {
-						log.Debugf("Validate - %s failed: %s", proxyHost, testErr)
 						newOurOfflineProxies = append(newOurOfflineProxies, pxy)
 					}
 					return
@@ -90,9 +85,7 @@ func (p *ForwardProxyCluster) ValidateProxiesThread() {
 						if bv3hiErr != nil {
 							okToAdd = false
 							newThirdpartyBrokenProxies = append(newThirdpartyBrokenProxies, pxy)
-							if config.CliArgs.LogThirdPartyTest {
+							log.Debugf(`%s failed third-party test for URL "%s" -- %s`, proxyHost, d, bv3hiErr)
-								log.Debugf(`%s failed third-party test for URL "%s" -- %s`, proxyHost, d, bv3hiErr)
-							}
 							break
 						}
 					}