refactor: remove forward auth, move module net/http to net/gphttp

internal/net/gphttp/loadbalancer/ip_hash.go

@@ -0,0 +1,91 @@
+package loadbalancer
+
+import (
+	"hash/fnv"
+	"net"
+	"net/http"
+	"sync"
+
+	"github.com/yusing/go-proxy/internal/gperr"
+	"github.com/yusing/go-proxy/internal/net/gphttp/middleware"
+)
+
+type ipHash struct {
+	*LoadBalancer
+
+	realIP *middleware.Middleware
+	pool   Servers
+	mu     sync.Mutex
+}
+
+func (lb *LoadBalancer) newIPHash() impl {
+	impl := &ipHash{LoadBalancer: lb}
+	if len(lb.Options) == 0 {
+		return impl
+	}
+	var err gperr.Error
+	impl.realIP, err = middleware.RealIP.New(lb.Options)
+	if err != nil {
+		gperr.LogError("invalid real_ip options, ignoring", err, &impl.l)
+	}
+	return impl
+}
+
+func (impl *ipHash) OnAddServer(srv Server) {
+	impl.mu.Lock()
+	defer impl.mu.Unlock()
+
+	for i, s := range impl.pool {
+		if s == srv {
+			return
+		}
+		if s == nil {
+			impl.pool[i] = srv
+			return
+		}
+	}
+
+	impl.pool = append(impl.pool, srv)
+}
+
+func (impl *ipHash) OnRemoveServer(srv Server) {
+	impl.mu.Lock()
+	defer impl.mu.Unlock()
+
+	for i, s := range impl.pool {
+		if s == srv {
+			impl.pool[i] = nil
+			return
+		}
+	}
+}
+
+func (impl *ipHash) ServeHTTP(_ Servers, rw http.ResponseWriter, r *http.Request) {
+	if impl.realIP != nil {
+		impl.realIP.ModifyRequest(impl.serveHTTP, rw, r)
+	} else {
+		impl.serveHTTP(rw, r)
+	}
+}
+
+func (impl *ipHash) serveHTTP(rw http.ResponseWriter, r *http.Request) {
+	ip, _, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		http.Error(rw, "Internal error", http.StatusInternalServerError)
+		impl.l.Err(err).Msg("invalid remote address " + r.RemoteAddr)
+		return
+	}
+	idx := hashIP(ip) % uint32(len(impl.pool))
+
+	srv := impl.pool[idx]
+	if srv == nil || srv.Status().Bad() {
+		http.Error(rw, "Service unavailable", http.StatusServiceUnavailable)
+	}
+	srv.ServeHTTP(rw, r)
+}
+
+func hashIP(ip string) uint32 {
+	h := fnv.New32a()
+	h.Write([]byte(ip))
+	return h.Sum32()
+}