Break on legacy multiple endpoints/users config

infra/conf/http.go

@@ -64,25 +64,24 @@ type HTTPClientConfig struct {
 func (v *HTTPClientConfig) Build() (proto.Message, error) {
 	config := new(http.ClientConfig)
 	if v.Address != nil {
-		if len(v.Username) == 0 {
 		v.Servers = []*HTTPRemoteConfig{
 			{
 				Address: v.Address,
 				Port:    v.Port,
 			},
 		}
-		} else {
+		if len(v.Username) > 0 {
-			v.Servers = []*HTTPRemoteConfig{
+			v.Servers[0].Users = []json.RawMessage{{}}
-				{
-					Address: v.Address,
-					Port:    v.Port,
-					Users:   []json.RawMessage{{}},
-				},
 		}
 	}
+	if len(v.Servers) != 1 {
+		return nil, errors.New(`HTTP settings: "servers" should have one and only one member. Multiple endpoints in "servers" should use multiple HTTP outbounds and routing balancer instead`)
 	}
 	config.Server = make([]*protocol.ServerEndpoint, len(v.Servers))
 	for idx, serverConfig := range v.Servers {
+		if len(serverConfig.Users) > 1 {
+			return nil, errors.New(`HTTP servers: "users" should have one member at most. Multiple members in "users" should use multiple HTTP outbounds and routing balancer instead`)
+		}
 		server := &protocol.ServerEndpoint{
 			Address: serverConfig.Address.Build(),
 			Port:    uint32(serverConfig.Port),

infra/conf/shadowsocks.go

@@ -200,8 +200,8 @@ func (v *ShadowsocksClientConfig) Build() (proto.Message, error) {
 			},
 		}
 	}
-	if len(v.Servers) == 0 {
+	if len(v.Servers) != 1 {
-		return nil, errors.New("0 Shadowsocks server configured.")
+		return nil, errors.New(`Shadowsocks settings: "servers" should have one and only one member. Multiple endpoints in "servers" should use multiple Shadowsocks outbounds and routing balancer instead`)
 	}
 
 	if len(v.Servers) == 1 {

infra/conf/socks.go

@@ -82,25 +82,24 @@ type SocksClientConfig struct {
 func (v *SocksClientConfig) Build() (proto.Message, error) {
 	config := new(socks.ClientConfig)
 	if v.Address != nil {
-		if len(v.Username) == 0 {
 		v.Servers = []*SocksRemoteConfig{
 			{
 				Address: v.Address,
 				Port:    v.Port,
 			},
 		}
-		} else {
+		if len(v.Username) > 0 {
-			v.Servers = []*SocksRemoteConfig{
+			v.Servers[0].Users = []json.RawMessage{{}}
-				{
-					Address: v.Address,
-					Port:    v.Port,
-					Users:   []json.RawMessage{{}},
-				},
 		}
 	}
+	if len(v.Servers) != 1 {
+		return nil, errors.New(`SOCKS settings: "servers" should have one and only one member. Multiple endpoints in "servers" should use multiple SOCKS outbounds and routing balancer instead`)
 	}
 	config.Server = make([]*protocol.ServerEndpoint, len(v.Servers))
 	for idx, serverConfig := range v.Servers {
+		if len(serverConfig.Users) > 1 {
+			return nil, errors.New(`SOCKS servers: "users" should have one member at most. Multiple members in "users" should use multiple SOCKS outbounds and routing balancer instead`)
+		}
 		server := &protocol.ServerEndpoint{
 			Address: serverConfig.Address.Build(),
 			Port:    uint32(serverConfig.Port),

infra/conf/trojan.go

@@ -51,8 +51,8 @@ func (c *TrojanClientConfig) Build() (proto.Message, error) {
 			},
 		}
 	}
-	if len(c.Servers) == 0 {
+	if len(c.Servers) != 1 {
-		return nil, errors.New("0 Trojan server configured.")
+		return nil, errors.New(`Trojan settings: "servers" should have one and only one member. Multiple endpoints in "servers" should use multiple Trojan outbounds and routing balancer instead`)
 	}
 
 	config := &trojan.ClientConfig{

infra/conf/vless.go

@@ -228,7 +228,7 @@ func (c *VLessOutboundConfig) Build() (proto.Message, error) {
 		}
 	}
 	if len(c.Vnext) != 1 {
-		return nil, errors.New(`VLESS settings: "vnext" should have one and only one member`)
+		return nil, errors.New(`VLESS settings: "vnext" should have one and only one member. Multiple endpoints in "vnext" should use multiple VLESS outbounds and routing balancer instead`)
 	}
 	config.Vnext = make([]*protocol.ServerEndpoint, len(c.Vnext))
 	for idx, rec := range c.Vnext {
@@ -236,7 +236,7 @@ func (c *VLessOutboundConfig) Build() (proto.Message, error) {
 			return nil, errors.New(`VLESS vnext: "address" is not set`)
 		}
 		if len(rec.Users) != 1 {
-			return nil, errors.New(`VLESS vnext: "users" should have one and only one member`)
+			return nil, errors.New(`VLESS vnext: "users" should have one and only one member. Multiple members in "users" should use multiple VLESS outbounds and routing balancer instead`)
 		}
 		spec := &protocol.ServerEndpoint{
 			Address: rec.Address.Build(),

infra/conf/vmess.go

@@ -139,16 +139,16 @@ func (c *VMessOutboundConfig) Build() (proto.Message, error) {
 			},
 		}
 	}
-	if len(c.Receivers) == 0 {
+	if len(c.Receivers) != 1 {
-		return nil, errors.New("0 VMess receiver configured")
+		return nil, errors.New(`VMess settings: "vnext" should have one and only one member. Multiple endpoints in "vnext" should use multiple VMess outbounds and routing balancer instead`)
 	}
 	serverSpecs := make([]*protocol.ServerEndpoint, len(c.Receivers))
 	for idx, rec := range c.Receivers {
-		if len(rec.Users) == 0 {
+		if len(rec.Users) != 1 {
-			return nil, errors.New("0 user configured for VMess outbound")
+			return nil, errors.New(`VMess vnext: "users" should have one and only one member. Multiple members in "users" should use multiple VMess outbounds and routing balancer instead`)
 		}
 		if rec.Address == nil {
-			return nil, errors.New("address is not set in VMess outbound config")
+			return nil, errors.New(`VMess vnext: "address" is not set`)
 		}
 		spec := &protocol.ServerEndpoint{
 			Address: rec.Address.Build(),