fix: change Transport.Address field to Transport.Address method

With new gRPC (both gateway and modules) it uses `grpc.NewClient` call to create clients.
It no longer support custom addresses without a `passthrough:` prefix. Previous fix didn't
account for that in some places, so this one changes the structure of `Transport` to always
return address in proper form for external users.

Signed-off-by: Dmitriy Matrenichev <dmitry.matrenichev@siderolabs.com>

go.mod

@@ -54,9 +54,9 @@ require (
 	github.com/jxskiss/base62 v1.1.0
 	github.com/mattn/go-shellwords v1.0.12
 	github.com/prometheus/client_golang v1.19.1
-	github.com/rs/xid v1.5.0
 	github.com/siderolabs/crypto v0.4.4
 	github.com/siderolabs/discovery-api v0.1.4
+	github.com/siderolabs/discovery-client v0.1.9
 	github.com/siderolabs/discovery-service v1.0.3-0.20240530092511-74bca2da5cc8
 	github.com/siderolabs/gen v0.5.0
 	github.com/siderolabs/go-api-signature v0.3.2
@@ -209,7 +209,6 @@ require (
 	github.com/ryszard/goskiplist v0.0.0-20150312221310-2dfbae5fcf46 // indirect
 	github.com/sergi/go-diff v1.3.1 // indirect
 	github.com/shabbyrobe/gocovmerge v0.0.0-20190829150210-3e036491d500 // indirect
-	github.com/siderolabs/discovery-client v0.1.9 // indirect
 	github.com/siderolabs/go-blockdevice v0.4.7 // indirect
 	github.com/siderolabs/go-kubeconfig v0.1.0 // indirect
 	github.com/siderolabs/net v0.4.0 // indirect

go.sum

@@ -379,8 +379,6 @@ github.com/rogpeppe/go-internal v1.12.0 h1:exVL4IDcn6na9z1rAb56Vxr+CgyK3nn3O+epU
 github.com/rogpeppe/go-internal v1.12.0/go.mod h1:E+RYuTGaKKdloAfM02xzb0FW3Paa99yedzYV+kq4uf4=
 github.com/rs/cors v1.10.1 h1:L0uuZVXIKlI1SShY2nhFfo44TYvDPQ1w4oFkUJNfhyo=
 github.com/rs/cors v1.10.1/go.mod h1:XyqrcTp5zjWr1wsJ8PIRZssZ8b/WMcMf71DJnit4EMU=
-github.com/rs/xid v1.5.0 h1:mKX4bl4iPYJtEIxp6CYiUuLQ/8DYMoz0PUdtGgMFRVc=
-github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
 github.com/russellhaering/goxmldsig v1.4.0 h1:8UcDh/xGyQiyrW+Fq5t8f+l2DLB1+zlhYzkPUJ7Qhys=
 github.com/russellhaering/goxmldsig v1.4.0/go.mod h1:gM4MDENBQf7M+V824SGfyIUVFWydB7n0KkEubVJl+Tw=
 github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=

internal/backend/grpc/grpc.go

@@ -106,13 +106,13 @@ func New(ctx context.Context, mux *http.ServeMux, servers []ServiceServer, trans
 	}
 
 	for _, srv := range servers {
-		err := srv.gateway(ctx, runtimeMux, transport.Address, opts)
+		err := srv.gateway(ctx, runtimeMux, transport.Address(), opts)
 		if err != nil {
 			return nil, fmt.Errorf("error registering gateway: %w", err)
 		}
 	}
 
-	if err := machine.RegisterMachineServiceHandlerFromEndpoint(ctx, runtimeMux, transport.Address, opts); err != nil {
+	if err := machine.RegisterMachineServiceHandlerFromEndpoint(ctx, runtimeMux, transport.Address(), opts); err != nil {
 		return nil, fmt.Errorf("error registering gateway: %w", err)
 	}
 

internal/backend/grpc/router/router.go

@@ -75,12 +75,7 @@ func NewRouter(
 	authEnabled bool,
 	verifier grpc.UnaryServerInterceptor,
 ) (*Router, error) {
-	address := transport.Address
-	if address == "grpc-conn" {
-		address = "passthrough:whatever"
-	}
-
-	omniConn, err := grpc.NewClient(address,
+	omniConn, err := grpc.NewClient(transport.Address(),
 		grpc.WithContextDialer(func(context.Context, string) (net.Conn, error) {
 			return transport.Dial()
 		}),

internal/backend/server.go

@@ -218,14 +218,14 @@ func (s *Server) Run(ctx context.Context) error {
 		return err
 	}
 
-	gatewayTransport := &memconn.Transport{Address: "gateway-conn"}
+	gatewayTransport := memconn.NewTransport("gateway-conn")
 
 	grpcServer, err := grpcomni.New(ctx, mux, serviceServers, gatewayTransport, s.logger, serverOptions...)
 	if err != nil {
 		return err
 	}
 
-	grpcTransport := &memconn.Transport{Address: "grpc-conn"}
+	grpcTransport := memconn.NewTransport("grpc-conn")
 
 	rtr, err := router.NewRouter(
 		grpcTransport,

internal/memconn/memconn.go

@@ -13,25 +13,36 @@ import (
 	"github.com/akutz/memconn"
 )
 
+// NewTransport creates a new transport.
+func NewTransport(address string) *Transport {
+	return &Transport{address: address}
+}
+
 // Transport is transport for in-memory connection.
 type Transport struct {
-	Address string
+	address string
 }
 
 // Listener creates new listener.
 func (l *Transport) Listener() (net.Listener, error) {
-	if l.Address == "" {
+	if l.address == "" {
 		return nil, errors.New("address is not set")
 	}
 
-	return memconn.Listen("memu", l.Address)
+	return memconn.Listen("memu", l.address)
 }
 
 // Dial creates a new connection.
 func (l *Transport) Dial() (net.Conn, error) {
-	if l.Address == "" {
+	if l.address == "" {
 		return nil, errors.New("address is not set")
 	}
 
-	return memconn.Dial("memu", l.Address)
+	return memconn.Dial("memu", l.address)
+}
+
+// Address returns the address. Since this is a memory-based connection, the address is always "passthrough:" + address,
+// because the address is not a real network address and gRPC tries to resolve it otherwise.
+func (l *Transport) Address() string {
+	return "passthrough:" + l.address
 }