Pass ServerName in the ConnInfo packet

elastic-agent-client.proto

@@ -15,14 +15,16 @@ option go_package = "pkg/proto;proto";
 message ConnInfo {
     // GRPC connection address.
     string addr = 1;
+    // Server name to use when connecting over TLS.
+    string server_name = 2;
     // Token that the application should send as the unique identifier when connecting over the GRPC.
-    string token = 2;
+    string token = 3;
     // CA certificate.
-    bytes ca_cert = 3;
+    bytes ca_cert = 4;
     // Peer certificate.
-    bytes peer_cert = 4;
+    bytes peer_cert = 5;
     // Peer private key.
-    bytes peer_key = 5;
+    bytes peer_key = 6;
 }
 
 // A status observed message is streamed from the application to Elastic Agent.

go.sum

@@ -26,6 +26,7 @@ github.com/golang/protobuf v1.4.2/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
+github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/hashicorp/errwrap v1.0.0 h1:hLrqtEDnRye3+sgx6z4qVLNuviH3MR5aQ0ykNJa/UYA=
 github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=

pkg/client/reader.go

@@ -7,12 +7,12 @@ package client
 import (
 	"crypto/tls"
 	"crypto/x509"
-	"google.golang.org/grpc/credentials"
 	"io"
 	"io/ioutil"
 
 	protobuf "github.com/golang/protobuf/proto"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
 
 	"github.com/elastic/elastic-agent-client/v7/pkg/proto"
 )
@@ -35,7 +35,7 @@ func NewFromReader(reader io.Reader, impl StateInterface, actions ...Action) (*C
 	caCertPool := x509.NewCertPool()
 	caCertPool.AppendCertsFromPEM(connInfo.CaCert)
 	trans := credentials.NewTLS(&tls.Config{
-		ServerName:   "localhost",
+		ServerName:   connInfo.ServerName,
 		Certificates: []tls.Certificate{cert},
 		RootCAs:      caCertPool,
 	})

pkg/client/reader_test.go

@@ -84,11 +84,12 @@ func TestNewFromReader_Connects(t *testing.T) {
 	defer srv.Stop()
 
 	connInfo := &proto.ConnInfo{
-		Addr:     fmt.Sprintf(":%d", srv.Port),
-		Token:    token,
-		CaCert:   ca.caPEM,
-		PeerCert: peer.Crt,
-		PeerKey:  peer.Key,
+		Addr:       fmt.Sprintf(":%d", srv.Port),
+		ServerName: "localhost",
+		Token:      token,
+		CaCert:     ca.caPEM,
+		PeerCert:   peer.Crt,
+		PeerKey:    peer.Key,
 	}
 	connInfoBytes, err := protobuf.Marshal(connInfo)
 	require.NoError(t, err)