client: Use first endpoint as http2 authority header

This doesn't fully fix authority in multiple endpoint scenario, but
should at least fixes single endpoint scenario.

client/v3/client.go

@@ -297,16 +297,28 @@ func (c *Client) dial(creds grpccredentials.TransportCredentials, dopts ...grpc.
 		dctx, cancel = context.WithTimeout(c.ctx, c.cfg.DialTimeout)
 		defer cancel() // TODO: Is this right for cases where grpc.WithBlock() is not set on the dial options?
 	}
-
-	initialEndpoints := strings.Join(c.Endpoints(), ";")
-	target := fmt.Sprintf("%s://%p/#initially=[%s]", resolver.Schema, c, initialEndpoints)
+	target := fmt.Sprintf("%s://%p/%s", resolver.Schema, c, authority(c.endpoints[0]))
 	conn, err := grpc.DialContext(dctx, target, opts...)
 	if err != nil {
 		return nil, err
 	}
 	return conn, nil
 }
 
+func authority(endpoint string) string {
+	spl := strings.SplitN(endpoint, "://", 2)
+	if len(spl) < 2 {
+		if strings.HasPrefix(endpoint, "unix:") {
+			return endpoint[len("unix:"):]
+		}
+		if strings.HasPrefix(endpoint, "unixs:") {
+			return endpoint[len("unixs:"):]
+		}
+		return endpoint
+	}
+	return spl[1]
+}
+
 func (c *Client) credentialsForEndpoint(ep string) grpccredentials.TransportCredentials {
 	r := endpoint.RequiresCredentials(ep)
 	switch r {

tests/e2e/ctl_v3_grpc_test.go

@@ -32,19 +32,19 @@ func TestAuthority(t *testing.T) {
 		clientURLPattern string
 
 		// Pattern used to validate authority received by server. Fields filled:
-		// %s - list of endpoints concatenated with ";"
+		// %d - will be filled with first member grpc port
 		expectAuthorityPattern string
 	}{
 		// HTTP schema
 		{
 			name:                   "http://domain[:port]",
 			clientURLPattern:       "http://localhost:%d",
-			expectAuthorityPattern: "#initially=[%s]",
+			expectAuthorityPattern: "localhost:%d",
 		},
 		{
 			name:                   "http://address[:port]",
 			clientURLPattern:       "http://127.0.0.1:%d",
-			expectAuthorityPattern: "#initially=[%s]",
+			expectAuthorityPattern: "127.0.0.1:%d",
 		},
 	}
 	for _, tc := range tcs {
@@ -71,7 +71,7 @@ func TestAuthority(t *testing.T) {
 				}
 
 				executeWithTimeout(t, 5*time.Second, func() {
-					assertAuthority(t, fmt.Sprintf(tc.expectAuthorityPattern, strings.Join(endpoints, ";")), epc)
+					assertAuthority(t, fmt.Sprintf(tc.expectAuthorityPattern, 20000), epc)
 				})
 			})
 

tests/integration/grpc_test.go

@@ -37,57 +37,58 @@ func TestAuthority(t *testing.T) {
 		clientURLPattern string
 
 		// Pattern used to validate authority received by server. Fields filled:
-		// %s - list of endpoints concatenated with ";"
+		// %d - will be filled with first member grpc port
+		// %s - will be filled with first member name
 		expectAuthorityPattern string
 	}{
 		{
 			name:                   "unix:path",
 			clientURLPattern:       "unix:localhost:%s",
-			expectAuthorityPattern: "#initially=[%s]",
+			expectAuthorityPattern: "localhost:%s",
 		},
 		{
 			name:                   "unix://absolute_path",
 			clientURLPattern:       "unix://localhost:%s",
-			expectAuthorityPattern: "#initially=[%s]",
+			expectAuthorityPattern: "localhost:%s",
 		},
 		// "unixs" is not standard schema supported by etcd
 		{
 			name:                   "unixs:absolute_path",
 			useTLS:                 true,
 			clientURLPattern:       "unixs:localhost:%s",
-			expectAuthorityPattern: "#initially=[%s]",
+			expectAuthorityPattern: "localhost:%s",
 		},
 		{
 			name:                   "unixs://absolute_path",
 			useTLS:                 true,
 			clientURLPattern:       "unixs://localhost:%s",
-			expectAuthorityPattern: "#initially=[%s]",
+			expectAuthorityPattern: "localhost:%s",
 		},
 		{
 			name:                   "http://domain[:port]",
 			useTCP:                 true,
 			clientURLPattern:       "http://localhost:%d",
-			expectAuthorityPattern: "#initially=[%s]",
+			expectAuthorityPattern: "localhost:%d",
 		},
 		{
 			name:                   "https://domain[:port]",
 			useTLS:                 true,
 			useTCP:                 true,
 			clientURLPattern:       "https://localhost:%d",
-			expectAuthorityPattern: "#initially=[%s]",
+			expectAuthorityPattern: "localhost:%d",
 		},
 		{
 			name:                   "http://address[:port]",
 			useTCP:                 true,
 			clientURLPattern:       "http://127.0.0.1:%d",
-			expectAuthorityPattern: "#initially=[%s]",
+			expectAuthorityPattern: "127.0.0.1:%d",
 		},
 		{
 			name:                   "https://address[:port]",
 			useTCP:                 true,
 			useTLS:                 true,
 			clientURLPattern:       "https://127.0.0.1:%d",
-			expectAuthorityPattern: "#initially=[%s]",
+			expectAuthorityPattern: "127.0.0.1:%d",
 		},
 	}
 	for _, tc := range tcs {
@@ -102,7 +103,6 @@ func TestAuthority(t *testing.T) {
 				cfg, tlsConfig := setupTLS(t, tc.useTLS, cfg)
 				clus := NewClusterV3(t, &cfg)
 				defer clus.Terminate(t)
-				endpoints := templateEndpoints(t, tc.clientURLPattern, clus)
 
 				kv := setupClient(t, tc.clientURLPattern, clus, tlsConfig)
 				defer kv.Close()
@@ -112,7 +112,7 @@ func TestAuthority(t *testing.T) {
 					t.Fatal(err)
 				}
 
-				assertAuthority(t, fmt.Sprintf(tc.expectAuthorityPattern, strings.Join(endpoints, ";")), clus)
+				assertAuthority(t, templateAuthority(t, tc.expectAuthorityPattern, clus.Members[0]), clus)
 			})
 		}
 	}
@@ -165,6 +165,21 @@ func templateEndpoints(t *testing.T, pattern string, clus *ClusterV3) []string {
 	return endpoints
 }
 
+func templateAuthority(t *testing.T, pattern string, m *member) string {
+	t.Helper()
+	authority := pattern
+	if strings.Contains(authority, "%d") {
+		authority = fmt.Sprintf(authority, GrpcPortNumber(m.UniqNumber, m.MemberNumber))
+	}
+	if strings.Contains(authority, "%s") {
+		authority = fmt.Sprintf(authority, m.Name)
+	}
+	if strings.Contains(authority, "%") {
+		t.Fatalf("Failed to template pattern, %% symbol left %q", authority)
+	}
+	return authority
+}
+
 func assertAuthority(t *testing.T, expectedAuthority string, clus *ClusterV3) {
 	t.Helper()
 	requestsFound := 0