frontend: add connection timeout

frontend/lgproxy.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"io"
+	"net"
 	"net/http"
 	"net/url"
 	"strconv"
@@ -14,6 +15,23 @@ type channelData struct {
 	data string
 }
 
+func createConnectionTimeoutRoundTripper(timeout int) http.RoundTripper {
+	context := net.Dialer{
+		Timeout: time.Duration(timeout) * time.Second,
+	}
+	return &http.Transport{
+		DialContext: context.DialContext,
+
+		// Default options from transport.go
+		Proxy:                 http.ProxyFromEnvironment,
+		ForceAttemptHTTP2:     true,
+		MaxIdleConns:          100,
+		IdleConnTimeout:       90 * time.Second,
+		TLSHandshakeTimeout:   10 * time.Second,
+		ExpectContinueTimeout: 1 * time.Second,
+	}
+}
+
 // Send commands to lgproxy instances in parallel, and retrieve their responses
 func batchRequest(servers []string, endpoint string, command string) []string {
 	// Channel and array for storing responses
@@ -47,7 +65,9 @@ func batchRequest(servers []string, endpoint string, command string) []string {
 			}
 			url := "http://" + hostname + ":" + strconv.Itoa(setting.proxyPort) + "/" + url.PathEscape(endpoint) + "?q=" + url.QueryEscape(command)
 			go func(url string, i int) {
-				client := http.Client{Timeout: time.Duration(setting.timeOut) * time.Second}
+				client := http.Client{
+					Transport: createConnectionTimeoutRoundTripper(setting.connectionTimeOut),
+					Timeout:   time.Duration(setting.timeOut) * time.Second}
 				response, err := client.Get(url)
 				if err != nil {
 					ch <- channelData{i, "request failed: " + err.Error() + "\n"}

frontend/main.go

@@ -7,24 +7,25 @@ import (
 )
 
 type settingType struct {
-	servers         []string
-	serversDisplay  []string
-	domain          string
-	proxyPort       int
-	whoisServer     string
-	listen          string
-	dnsInterface    string
-	netSpecificMode string
-	titleBrand      string
-	navBarBrand     string
-	navBarBrandURL  string
-	navBarAllServer string
-	navBarAllURL    string
-	bgpmapInfo      string
-	telegramBotName string
-	protocolFilter  []string
-	nameFilter      string
-	timeOut         int
+	servers           []string
+	serversDisplay    []string
+	domain            string
+	proxyPort         int
+	whoisServer       string
+	listen            string
+	dnsInterface      string
+	netSpecificMode   string
+	titleBrand        string
+	navBarBrand       string
+	navBarBrandURL    string
+	navBarAllServer   string
+	navBarAllURL      string
+	bgpmapInfo        string
+	telegramBotName   string
+	protocolFilter    []string
+	nameFilter        string
+	timeOut           int
+	connectionTimeOut int
 }
 
 var setting settingType

frontend/settings.go

@@ -9,23 +9,24 @@ import (
 )
 
 type viperSettingType struct {
-	Servers         string `mapstructure:"servers"`
-	Domain          string `mapstructure:"domain"`
-	ProxyPort       int    `mapstructure:"proxy_port"`
-	WhoisServer     string `mapstructure:"whois"`
-	Listen          string `mapstructure:"listen"`
-	DNSInterface    string `mapstructure:"dns_interface"`
-	NetSpecificMode string `mapstructure:"net_specific_mode"`
-	TitleBrand      string `mapstructure:"title_brand"`
-	NavBarBrand     string `mapstructure:"navbar_brand"`
-	NavBarBrandURL  string `mapstructure:"navbar_brand_url"`
-	NavBarAllServer string `mapstructure:"navbar_all_servers"`
-	NavBarAllURL    string `mapstructure:"navbar_all_url"`
-	BgpmapInfo      string `mapstructure:"bgpmap_info"`
-	TelegramBotName string `mapstructure:"telegram_bot_name"`
-	ProtocolFilter  string `mapstructure:"protocol_filter"`
-	NameFilter      string `mapstructure:"name_filter"`
-	TimeOut         int    `mapstructure:"timeout"`
+	Servers           string `mapstructure:"servers"`
+	Domain            string `mapstructure:"domain"`
+	ProxyPort         int    `mapstructure:"proxy_port"`
+	WhoisServer       string `mapstructure:"whois"`
+	Listen            string `mapstructure:"listen"`
+	DNSInterface      string `mapstructure:"dns_interface"`
+	NetSpecificMode   string `mapstructure:"net_specific_mode"`
+	TitleBrand        string `mapstructure:"title_brand"`
+	NavBarBrand       string `mapstructure:"navbar_brand"`
+	NavBarBrandURL    string `mapstructure:"navbar_brand_url"`
+	NavBarAllServer   string `mapstructure:"navbar_all_servers"`
+	NavBarAllURL      string `mapstructure:"navbar_all_url"`
+	BgpmapInfo        string `mapstructure:"bgpmap_info"`
+	TelegramBotName   string `mapstructure:"telegram_bot_name"`
+	ProtocolFilter    string `mapstructure:"protocol_filter"`
+	NameFilter        string `mapstructure:"name_filter"`
+	TimeOut           int    `mapstructure:"timeout"`
+	ConnectionTimeOut int    `mapstructure:"connection_timeout"`
 }
 
 // Parse settings with viper, and convert to legacy setting format
@@ -87,9 +88,12 @@ func parseSettings() {
 	pflag.String("name-filter", "", "protocol name regex to hide in summary tables (RE2 syntax); defaults to none if not set")
 	viper.BindPFlag("name_filter", pflag.Lookup("name-filter"))
 
-	pflag.Int("time-out", 120, "time before request timed out, in seconds; defaults to 120 if not set")
+	pflag.Int("time-out", 120, "time before backend HTTP request times out, in seconds; defaults to 120 if not set")
 	viper.BindPFlag("timeout", pflag.Lookup("time-out"))
 
+	pflag.Int("connection-time-out", 5, "time before backend TCP connection times out, in seconds; defaults to 5 if not set")
+	viper.BindPFlag("connection_timeout", pflag.Lookup("connection-time-out"))
+
 	pflag.Parse()
 
 	if err := viper.ReadInConfig(); err != nil {
@@ -139,6 +143,7 @@ func parseSettings() {
 
 	setting.nameFilter = viperSettings.NameFilter
 	setting.timeOut = viperSettings.TimeOut
+	setting.connectionTimeOut = viperSettings.ConnectionTimeOut
 
 	fmt.Printf("%#v\n", setting)
 }