comment on why we use MTLS endpoint with S2A.

rmehta19 · rmehta19 · commit 2afdbbc1abb1 · 2025-03-11T11:28:23.000-07:00
diff --git a/gax-java/gax-grpc/src/main/java/com/google/api/gax/grpc/InstantiatingGrpcChannelProvider.java b/gax-java/gax-grpc/src/main/java/com/google/api/gax/grpc/InstantiatingGrpcChannelProvider.java
@@ -690,6 +690,7 @@ private ManagedChannel createSingleChannel() throws IOException {
             channelCredentials =
                 CompositeChannelCredentials.create(channelCredentials, mtlsS2ACallCredentials);
           }
+          // Connect to the MTLS endpoint when using S2A because S2A is used to perform an MTLS handshake.
           builder = Grpc.newChannelBuilder(mtlsEndpoint, channelCredentials);
         } else {
           // Use default if we cannot initialize channel credentials via DCA or S2A.

Original file line number	Diff line number	Diff line change
`@@ -690,6 +690,7 @@ private ManagedChannel createSingleChannel() throws IOException {`
`690`	`690`	`channelCredentials =`
`691`	`691`	`CompositeChannelCredentials.create(channelCredentials, mtlsS2ACallCredentials);`
`692`	`692`	`}`
	`693`	`+ // Connect to the MTLS endpoint when using S2A because S2A is used to perform an MTLS handshake.`
`693`	`694`	`builder = Grpc.newChannelBuilder(mtlsEndpoint, channelCredentials);`
`694`	`695`	`} else {`
`695`	`696`	`// Use default if we cannot initialize channel credentials via DCA or S2A.`