More config options, bug fixes

README.md

@@ -20,10 +20,14 @@ and error handling. Built for automated web scraping.
 ```json
 {
   "addr": "localhost:5050",
+  "timeout": "15s",
+  "wait": "4s",
+  "multiplier": 2.5,
+  "retries": 3,
   "proxies": [
     {
       "name": "squid_P0",
-      "url": "http://p0.exemple.com:8080"
+      "url": "http://user:pass@p0.exemple.com:8080"
     },
     {
       "name": "privoxy_P1",
@@ -38,7 +42,7 @@ and error handling. Built for automated web scraping.
     },
     "reddit.com": {
       "every": "2s",
-      "burst": 1,
+      "burst": 2,
       "headers": {"User-Agent":  "mybot_v0.1"}
     }
   }

config.go

@@ -2,16 +2,19 @@ package main
 
 import (
 	"encoding/json"
+	"fmt"
 	"golang.org/x/time/rate"
 	"io/ioutil"
 	"os"
+	"strings"
 	"time"
 )
 
 type HostConfig struct {
-	Every   string            `json:"every"`
+	EveryStr string            `json:"every"`
 	Burst    int               `json:"burst"`
 	Headers  map[string]string `json:"headers"`
+	Every    time.Duration
 }
 
 type ProxyConfig struct {
@@ -21,8 +24,14 @@ type ProxyConfig struct {
 
 var config struct {
 	Addr       string                 `json:"addr"`
-	Hosts   map[string]HostConfig `json:"hosts"`
+	TimeoutStr string                 `json:"timeout"`
+	WaitStr    string                 `json:"wait"`
+	Multiplier float64                `json:"multiplier"`
+	Retries    int                    `json:"retries"`
+	Hosts      map[string]*HostConfig `json:"hosts"`
 	Proxies    []ProxyConfig          `json:"proxies"`
+	Wait       int64
+	Timeout    time.Duration
 }
 
 func loadConfig() {
@@ -35,15 +44,47 @@ func loadConfig() {
 
 	err = json.Unmarshal(configBytes, &config)
 	handleErr(err)
+
+	validateConfig()
+
+	config.Timeout, err = time.ParseDuration(config.TimeoutStr)
+	wait, err := time.ParseDuration(config.WaitStr)
+	config.Wait = int64(wait)
+
+	for _, conf := range config.Hosts {
+		conf.Every, err = time.ParseDuration(conf.EveryStr)
+		handleErr(err)
+	}
+}
+
+func validateConfig() {
+
+	hasDefaultHost := false
+
+	for host, conf := range config.Hosts {
+
+		if host == "*" {
+			hasDefaultHost = true
+		}
+
+		for k := range conf.Headers {
+			if strings.ToLower(k) == "accept-encoding" {
+				panic(fmt.Sprintf("headers config for '%s':"+
+					" Do not set the Accept-Encoding header, it breaks goproxy", host))
+			}
+		}
+	}
+
+	if !hasDefaultHost {
+		panic("config.json: You must specify a default host ('*')")
+	}
 }
 
 func applyConfig(proxy *Proxy) {
 
 	for host, conf := range config.Hosts {
-		duration, err := time.ParseDuration(conf.Every)
-		handleErr(err)
 		proxy.Limiters[host] = &ExpiringLimiter{
-			rate.NewLimiter(rate.Every(duration), conf.Burst),
+			rate.NewLimiter(rate.Every(conf.Every), conf.Burst),
 			time.Now(),
 		}
 	}

config.json

@@ -1,5 +1,9 @@
 {
   "addr": "localhost:5050",
+  "timeout": "15s",
+  "wait": "4s",
+  "multiplier": 2.5,
+  "retries": 3,
   "proxies": [
     {
       "name": "p0",
@@ -12,14 +16,20 @@
   ],
   "hosts": {
     "*": {
-      "every": "10s",
+      "every": "500s",
-      "burst": 1,
+      "burst": 25,
-      "headers": {}
+      "headers": {
+        "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
+        "Cache-Control": "max-age=0",
+        "Connection": "keep-alive",
+        "User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:67.0) Gecko/20100101 Firefox/67.0"
+      }
     },
     "reddit.com": {
-      "every": "100s",
+      "every": "2s",
-      "burst": 1,
+      "burst": 2,
-      "headers": {}
+      "headers": {
+      }
     }
   }
 }

gc.go

@@ -32,7 +32,7 @@ func (b *Balancer) cleanAllExpiredLimits() {
 
 	logrus.WithFields(logrus.Fields{
 		"removed": before - after,
-	}).Info("Did limiters cleanup")
+	}).Info("Cleaned up limiters")
 }
 
 func cleanExpiredLimits(proxy *Proxy) {

main.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"flag"
 	"github.com/elazarl/goproxy"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -58,11 +57,12 @@ func (p *Proxy) getLimiter(host string) *rate.Limiter {
 }
 
 func (p *Proxy) makeNewLimiter(host string) *ExpiringLimiter {
-	every := time.Millisecond //todo load default from conf
+
+	defaultConf := config.Hosts["*"]
 
 	newExpiringLimiter := &ExpiringLimiter{
 		LastRead: time.Now(),
-		Limiter:  rate.NewLimiter(rate.Every(every), 1),
+		Limiter:  rate.NewLimiter(rate.Every(defaultConf.Every), defaultConf.Burst),
 	}
 
 	p.Limiters[host] = newExpiringLimiter
@@ -76,7 +76,12 @@ func (p *Proxy) makeNewLimiter(host string) *ExpiringLimiter {
 
 func simplifyHost(host string) string {
 	if strings.HasPrefix(host, "www.") {
-		return host[4:]
+		host = host[4:]
+	}
+
+	col := strings.LastIndex(host, ":")
+	if col > 0 {
+		host = host[:col]
 	}
 
 	return host
@@ -104,6 +109,7 @@ func New() *Balancer {
 			logrus.WithFields(logrus.Fields{
 				"proxy":      p.Name,
 				"connexions": p.Connections,
+				"host":       r.Host,
 			}).Trace("Routing request")
 
 			resp, err := p.processRequest(r)
@@ -118,22 +124,38 @@ func New() *Balancer {
 	return balancer
 }
 
+func applyHeaders(r *http.Request) *http.Request {
+
+	if conf, ok := config.Hosts["*"]; ok {
+		for k, v := range conf.Headers {
+			r.Header.Set(k, v)
+		}
+	}
+
+	sHost := simplifyHost(r.Host)
+	if conf, ok := config.Hosts[sHost]; ok {
+		for k, v := range conf.Headers {
+			r.Header.Set(k, v)
+		}
+	}
+	return r
+}
+
 func (p *Proxy) processRequest(r *http.Request) (*http.Response, error) {
 
 	p.Connections += 1
 	defer func() {
 		p.Connections -= 1
 	}()
-	retries := 1
+	retries := 0
-	const maxRetries = 5
 
 	p.waitRateLimit(r)
-	proxyReq := preprocessRequest(cloneRequest(r))
+	proxyReq := applyHeaders(cloneRequest(r))
 
 	for {
 
-		if retries > maxRetries {
+		if retries >= config.Retries {
-			return nil, errors.Errorf("giving up after %d retries", maxRetries)
+			return nil, errors.Errorf("giving up after %d retries", config.Retries)
 		}
 
 		resp, err := p.HttpClient.Do(proxyReq)
@@ -177,22 +199,15 @@ func (p *Proxy) processRequest(r *http.Request) (*http.Response, error) {
 
 func (b *Balancer) Run() {
 
-	addr := flag.String("addr", "localhost:5050", "listen address")
-	flag.Parse()
-
 	//b.Verbose = true
 	logrus.WithFields(logrus.Fields{
-		"addr": *addr,
+		"addr": config.Addr,
 	}).Info("Listening")
 
-	err := http.ListenAndServe(*addr, b.server)
+	err := http.ListenAndServe(config.Addr, b.server)
 	logrus.Fatal(err)
 }
 
-func preprocessRequest(r *http.Request) *http.Request {
-	return r
-}
-
 func cloneRequest(r *http.Request) *http.Request {
 
 	proxyReq := &http.Request{
@@ -223,7 +238,6 @@ func NewProxy(name, stringUrl string) (*Proxy, error) {
 	}
 
 	var httpClient *http.Client
-	//TODO: setup extra headers & qargs here
 	if parsedUrl == nil {
 		httpClient = &http.Client{}
 	} else {
@@ -234,6 +248,8 @@ func NewProxy(name, stringUrl string) (*Proxy, error) {
 		}
 	}
 
+	httpClient.Timeout = config.Timeout
+
 	return &Proxy{
 		Name:       name,
 		Url:        parsedUrl,

retry.go

@@ -21,20 +21,17 @@ func isPermanentError(err error) bool {
 	if ok {
 		opErr, ok = urlErr.Err.(*net.OpError)
 		if !ok {
+			if urlErr.Err != nil && urlErr.Err.Error() == "Proxy Authentication Required" {
+				logrus.Warn("Got 'Proxy Authentication Required'. Did you forget to configure the password for a proxy?")
+				return true
+			}
 			return false
 		}
 	} else {
-		netErr, ok := err.(net.Error)
+		_, ok := err.(net.Error)
 		if ok {
-			if netErr.Timeout() {
 			return false
 		}
-
-			opErr, ok = netErr.(*net.OpError)
-			if !ok {
-				return false
-			}
-		}
 	}
 
 	//This should not happen...
@@ -80,10 +77,7 @@ func isPermanentError(err error) bool {
 
 func waitTime(retries int) time.Duration {
 
-	const multiplier = 1.5
+	return time.Duration(config.Wait * int64(math.Pow(config.Multiplier, float64(retries))))
-	const wait = int64(5 * time.Second)
-
-	return time.Duration(wait * int64(math.Pow(multiplier, float64(retries))))
 }
 
 func (p *Proxy) waitRateLimit(r *http.Request) {
@@ -101,7 +95,7 @@ func (p *Proxy) waitRateLimit(r *http.Request) {
 	delay := reservation.Delay()
 	if delay > 0 {
 		logrus.WithFields(logrus.Fields{
-			"time": delay,
+			"wait": delay,
 		}).Trace("Sleeping")
 		time.Sleep(delay)
 	}
@@ -115,10 +109,15 @@ func shouldRetryHttpCode(code int) bool {
 
 	switch {
 	case code == 403:
+		fallthrough
 	case code == 408:
+		fallthrough
 	case code == 429:
+		fallthrough
 	case code == 444:
+		fallthrough
 	case code == 499:
+		fallthrough
 	case code >= 500:
 		return true
 	}

test/web.py

@@ -5,7 +5,7 @@ app = Flask(__name__)
 
 
 @app.route("/")
-def hello():
+def slow():
     time.sleep(90)
     return "Hello World!"
 
@@ -17,7 +17,11 @@ def e500():
 
 @app.route("/404")
 def e404():
-    time.sleep(0.5)
+    return Response(status=404)
+
+
+@app.route("/403")
+def e403():
     return Response(status=404)