func newProxy(cfg *config.Config) *proxy.Proxy {
if err := route.SetPickerStrategy(cfg.Proxy.Strategy); err != nil {
log.Fatal("[FATAL] ", err)
}
log.Printf("[INFO] Using routing strategy %q", cfg.Proxy.Strategy)
tr := &http.Transport{
ResponseHeaderTimeout: cfg.Proxy.ResponseHeaderTimeout,
MaxIdleConnsPerHost: cfg.Proxy.MaxConn,
Dial: (&net.Dialer{
Timeout: cfg.Proxy.DialTimeout,
KeepAlive: cfg.Proxy.KeepAliveTimeout,
}).Dial,
}
return proxy.New(tr, cfg.Proxy)
}
/**
使用配置信息创建并返回HTTP代理服务器的句柄
*/
func newHTTPProxy(cfg *config.Config) http.Handler {
// 设置路由拣选策略
if err := route.SetPickerStrategy(cfg.Proxy.Strategy); err != nil {
exit.Fatal("[FATAL] ", err)
}
log.Printf("[INFO] Using routing strategy %q", cfg.Proxy.Strategy)
// 设置路由匹配器
if err := route.SetMatcher(cfg.Proxy.Matcher); err != nil {
exit.Fatal("[FATAL] ", err)
}
log.Printf("[INFO] Using routing matching %q", cfg.Proxy.Matcher)
// 配置转换器
tr := &http.Transport{
ResponseHeaderTimeout: cfg.Proxy.ResponseHeaderTimeout,
MaxIdleConnsPerHost: cfg.Proxy.MaxConn,
Dial: (&net.Dialer{
Timeout: cfg.Proxy.DialTimeout,
KeepAlive: cfg.Proxy.KeepAliveTimeout,
}).Dial,
}
/**
@todo 上面代码中有疑问，如下代码：
Dial: (&net.Dialer{
Timeout: cfg.Proxy.DialTimeout,
KeepAlive: cfg.Proxy.KeepAliveTimeout,
}).Dial
第一行为何用 &net.Dialer ? 即为何使用引用？
原因是 net包的Dialer结构体(struct)的方法Dial是指针类型，所以只有使用引用定义的时候才能访问到该函数
*/
// 生成并返回HTTP代理句柄
return proxy.NewHTTPProxy(tr, cfg.Proxy)
}
func main() {
var cfg string
var v bool
flag.StringVar(&cfg, "cfg", "", "path to config file")
flag.BoolVar(&v, "v", false, "show version")
flag.Parse()
if v {
fmt.Println(version)
return
}
log.Printf("[INFO] Version %s starting", version)
if cfg != "" {
if err := loadConfig(cfg); err != nil {
log.Fatal("[FATAL] ", err)
}
}
if err := metrics.Init(metricsTarget, metricsPrefix, metricsInterval, metricsGraphiteAddr); err != nil {
log.Fatal("[FATAL] ", err)
}
if os.Getenv("GOMAXPROCS") == "" {
log.Print("[INFO] Setting GOMAXPROCS=", gomaxprocs)
runtime.GOMAXPROCS(gomaxprocs)
} else {
log.Print("[INFO] Using GOMAXPROCS=", os.Getenv("GOMAXPROCS"), " from env")
}
if os.Getenv("GOGC") == "" {
log.Print("[INFO] Setting GOGC=", gogc)
debug.SetGCPercent(gogc)
} else {
log.Print("[INFO] Using GOGC=", os.Getenv("GOGC"), " from env")
}
if proxyRoutes == "" {
useDynamicRoutes()
} else {
useStaticRoutes()
}
if err := route.SetPickerStrategy(proxyStrategy); err != nil {
log.Fatal("[FATAL] ", err)
}
consul.Addr = consulAddr
consul.URL = consulURL
dc, err := consul.Datacenter()
if err != nil {
log.Fatal("[FATAL] ", err)
}
log.Printf("[INFO] Using routing strategy %q", proxyStrategy)
log.Printf("[INFO] Connecting to consul on %q in datacenter %q", consulAddr, dc)
log.Printf("[INFO] Consul can be reached via %q", consulURL)
log.Printf("[INFO] UI listening on %q", uiAddr)
go func() {
if err := ui.Start(uiAddr, consulKVPath); err != nil {
log.Fatal("[FATAL] ui: ", err)
}
}()
tr := &http.Transport{
ResponseHeaderTimeout: proxyTimeout,
MaxIdleConnsPerHost: proxyMaxConn,
Dial: (&net.Dialer{
Timeout: proxyDialTimeout,
KeepAlive: proxyTimeout,
}).Dial,
}
proxy := route.NewProxy(tr, proxyHeaderClientIP, proxyHeaderTLS, proxyHeaderTLSValue)
listen(proxyAddr, proxyShutdownWait, proxy)
}