Support Unix Domain Sockets (#328)

auth_server/main.go

@@ -21,6 +21,7 @@ import (
 	"crypto/tls"
 	"flag"
 	"math/rand"
+	"net"
 	"net/http"
 	"os"
 	"os/signal"
@@ -134,15 +135,35 @@ func ServeOnce(c *server.Config, cf string) (*server.AuthServer, *http.Server) {
 		Handler:   as,
 		TLSConfig: tlsConfig,
 	}
+
+	var listener net.Listener
+	if c.Server.Net == "unix" {
+		// Remove socket, if exists
+		if _, err := os.Stat(c.Server.ListenAddress); err == nil {
+			if err := os.Remove(c.Server.ListenAddress); err != nil {
+				glog.Fatal(err.Error())
+			}
+		}
+		listener, err = net.Listen("unix", c.Server.ListenAddress)
+		if err != nil {
+			glog.Fatal(err.Error())
+		}
+	} else {
+		listener, err = net.Listen("tcp", c.Server.ListenAddress)
+		if err != nil {
+			glog.Fatal(err.Error())
+		}
+	}
+
 	go func() {
 		if c.Server.CertFile == "" && c.Server.KeyFile == "" {
-			if err := hs.ListenAndServe(); err != nil {
+			if err := hs.Serve(listener); err != nil {
 				if err == http.ErrServerClosed {
 					return
 				}
 			}
 		} else {
-			if err := hs.ListenAndServeTLS(c.Server.CertFile, c.Server.KeyFile); err != nil {
+			if err := hs.ServeTLS(listener, c.Server.CertFile, c.Server.KeyFile); err != nil {
 				if err == http.ErrServerClosed {
 					return
 				}

auth_server/server/config.go

@@ -56,6 +56,7 @@ type Config struct {
 
 type ServerConfig struct {
 	ListenAddress       string            `yaml:"addr,omitempty"`
+	Net                 string            `yaml:"net,omitempty"`
 	PathPrefix          string            `yaml:"path_prefix,omitempty"`
 	RealIPHeader        string            `yaml:"real_ip_header,omitempty"`
 	RealIPPos           int               `yaml:"real_ip_pos,omitempty"`
@@ -150,6 +151,13 @@ func validate(c *Config) error {
 	if c.Server.ListenAddress == "" {
 		return errors.New("server.addr is required")
 	}
+	if c.Server.Net != "unix" && c.Server.Net != "tcp" {
+		if c.Server.Net == "" {
+			c.Server.Net = "tcp"
+		} else {
+			return errors.New("server.net must be unix or tcp")
+		}
+	}
 	if c.Server.PathPrefix != "" && !strings.HasPrefix(c.Server.PathPrefix, "/") {
 		return errors.New("server.path_prefix must be an absolute path")
 	}

examples/reference.yml

@@ -12,8 +12,12 @@
 
 server:  # Server settings.
   # Address to listen on.
+  # Can be HOST:PORT for TCP or file path (e.g. /run/docker_auth.sock) for Unix socket.
   addr: ":5001"
 
+  # Network, can be "tcp" or "unix" ("tcp" if unspecified).
+  net: "tcp"
+
   # URL path prefix to use.
   path_prefix: ""