support redis+socket scheme in url

redis/conn.go

@@ -324,71 +324,90 @@ func DialURL(rawurl string, options ...DialOption) (Conn, error) {
 }
 
 // DialURLContext connects to a Redis server at the given URL using the Redis
-// URI scheme. URLs should follow the draft IANA specification for the
-// scheme (https://www.iana.org/assignments/uri-schemes/prov/redis).
+// URI scheme. It supports:
+// redis - unencrypted tcp connection
+// rediss - TLS encrypted tcp connection
+// redis+unix - UNIX socket connection
 func DialURLContext(ctx context.Context, rawurl string, options ...DialOption) (Conn, error) {
 	u, err := url.Parse(rawurl)
 	if err != nil {
 		return nil, err
 	}
-
-	if u.Scheme != "redis" && u.Scheme != "rediss" {
-		return nil, fmt.Errorf("invalid redis URL scheme: %s", u.Scheme)
-	}
-
 	if u.Opaque != "" {
 		return nil, fmt.Errorf("invalid redis URL, url is opaque: %s", rawurl)
 	}
 
-	// As per the IANA draft spec, the host defaults to localhost and
-	// the port defaults to 6379.
-	host, port, err := net.SplitHostPort(u.Host)
-	if err != nil {
-		// assume port is missing
-		host = u.Host
-		port = "6379"
-	}
-	if host == "" {
-		host = "localhost"
-	}
-	address := net.JoinHostPort(host, port)
-
-	if u.User != nil {
-		password, isSet := u.User.Password()
-		username := u.User.Username()
-		if isSet {
-			if username != "" {
-				// ACL
-				options = append(options, DialUsername(username), DialPassword(password))
-			} else {
-				// requirepass - user-info username:password with blank username
-				options = append(options, DialPassword(password))
+	var (
+		network string
+		address string
+		db      = 0
+	)
+	switch u.Scheme {
+	case "redis", "rediss":
+		network = "tcp"
+
+		// As per the IANA draft spec, the host defaults to localhost and
+		// the port defaults to 6379.
+		host, port, err := net.SplitHostPort(u.Host)
+		if err != nil {
+			// assume port is missing
+			host = u.Host
+			port = "6379"
+		}
+		if host == "" {
+			host = "localhost"
+		}
+		address = net.JoinHostPort(host, port)
+		if u.User != nil {
+			password, isSet := u.User.Password()
+			username := u.User.Username()
+			if isSet {
+				if username != "" {
+					// ACL
+					options = append(options, DialUsername(username), DialPassword(password))
+				} else {
+					// requirepass - user-info username:password with blank username
+					options = append(options, DialPassword(password))
+				}
+			} else if username != "" {
+				// requirepass - redis-cli compatibility which treats as single arg in user-info as a password
+				options = append(options, DialPassword(username))
 			}
-		} else if username != "" {
-			// requirepass - redis-cli compatibility which treats as single arg in user-info as a password
-			options = append(options, DialPassword(username))
 		}
-	}
-
-	match := pathDBRegexp.FindStringSubmatch(u.Path)
-	if len(match) == 2 {
-		db := 0
-		if len(match[1]) > 0 {
-			db, err = strconv.Atoi(match[1])
+		match := pathDBRegexp.FindStringSubmatch(u.Path)
+		if len(match) == 2 {
+			if len(match[1]) > 0 {
+				db, err = strconv.Atoi(match[1])
+				if err != nil {
+					return nil, fmt.Errorf("invalid database: %s", u.Path[1:])
+				}
+			}
+			if db != 0 {
+				options = append(options, DialDatabase(db))
+			}
+		} else if u.Path != "" {
+			return nil, fmt.Errorf("invalid database: %s", u.Path[1:])
+		}
+		options = append(options, DialUseTLS(u.Scheme == "rediss"))
+	case "redis+unix":
+		network = "unix"
+		address = u.Path
+		dbParameter := u.Query().Get("db")
+		if dbParameter != "" {
+			db, err = strconv.Atoi(dbParameter)
 			if err != nil {
 				return nil, fmt.Errorf("invalid database: %s", u.Path[1:])
 			}
+			if db != 0 {
+				options = append(options, DialDatabase(db))
+			}
 		}
-		if db != 0 {
-			options = append(options, DialDatabase(db))
-		}
-	} else if u.Path != "" {
-		return nil, fmt.Errorf("invalid database: %s", u.Path[1:])
+		options = append(options, DialUseTLS(false))
+	default:
+		return nil, fmt.Errorf("invalid redis URL scheme: %s", u.Scheme)
 	}
 
-	options = append(options, DialUseTLS(u.Scheme == "rediss"))
-
-	return DialContext(ctx, "tcp", address, options...)
+	return DialContext(ctx, network, address, options...)
 }
 
 // NewConn returns a new Redigo connection for the given net connection.

redis/conn_test.go

@@ -23,10 +23,11 @@ import (
 	"io"
 	"math"
 	"net"
-	"sync"
 	"os"
+	"path/filepath"
 	"reflect"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -661,6 +662,8 @@ func TestDialURLHost(t *testing.T) {
 	}
 }
 
+var workingDirectory, _ = os.Getwd()
+
 var dialURLTests = []struct {
 	description string
 	url         string
@@ -680,6 +683,9 @@ var dialURLTests = []struct {
 	{"database 3", "redis://localhost/3", "+OK\r\n", "*2\r\n$6\r\nSELECT\r\n$1\r\n3\r\n"},
 	{"database 99", "redis://localhost/99", "+OK\r\n", "*2\r\n$6\r\nSELECT\r\n$2\r\n99\r\n"},
 	{"no database", "redis://localhost/", "+OK\r\n", ""},
+	{"absolute socket path", "redis+unix://" + filepath.Join(workingDirectory, "server.sock"), "+OK\r\n", ""},
+	{"relative socket path", "redis+unix://./server.sock", "+OK\r\n", ""},
+	{"unix socket path database 99", "redis+unix://./server.sock?db=99", "+OK\r\n", "*2\r\n$6\r\nSELECT\r\n$2\r\n99\r\n"},
 }
 
 func TestDialURL(t *testing.T) {

redis/test_test.go

@@ -21,7 +21,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"regexp"
@@ -40,10 +39,11 @@ var (
 	ErrNegativeInt = errNegativeInt
 
 	serverPath     = flag.String("redis-server", "redis-server", "Path to redis server binary")
-	serverAddress  = flag.String("redis-address", "127.0.0.1", "The address of the server")
+	serverAddress  = flag.String("redis-address", "127.0.0.1", "The TCP address of the server")
 	serverBasePort = flag.Int("redis-port", 16379, "Beginning of port range for test servers")
+	serverSocket   = flag.String("redis-socket", "./server.sock", "The UNIX socket of the server")
 	serverLogName  = flag.String("redis-log", "", "Write Redis server logs to `filename`")
-	serverLog      = ioutil.Discard
+	serverLog      = io.Discard
 
 	defaultServerMu  sync.Mutex
 	defaultServer    *Server
@@ -190,6 +190,7 @@ func DefaultServerAddr() (string, error) {
 		"default",
 		"--port", strconv.Itoa(*serverBasePort),
 		"--bind", *serverAddress,
+		"--unixsocket", *serverSocket,
 		"--save", "",
 		"--appendonly", "no")
 	return addr, defaultServerErr