Set the port to connect to the sdkserver based on the AGONES_SDK_GRPC…

…_PORT

environment variable.

examples/cpp-simple/server.cc

@@ -50,7 +50,7 @@ int main() {
 
   std::cout << "Attempting to connect...\n" << std::flush;
   if (!sdk->Connect()) {
-    std::cerr << "Could not connect to the sidecar. Exiting!\n";
+    std::cerr << "Exiting!\n";
     return -1;
   }
   std::cout << "...handshake complete.\n" << std::flush;

sdks/cpp/src/agones/sdk.cc

@@ -20,15 +20,18 @@
 namespace agones {
 
 struct SDK::SDKImpl {
+  std::string host_;
   std::shared_ptr<grpc::Channel> channel_;
   std::unique_ptr<agones::dev::sdk::SDK::Stub> stub_;
   std::unique_ptr<grpc::ClientWriter<agones::dev::sdk::Empty>> health_;
   std::unique_ptr<grpc::ClientContext> health_context_;
 };
 
 SDK::SDK() : pimpl_{std::make_unique<SDKImpl>()} {
-  pimpl_->channel_ = grpc::CreateChannel("localhost:59357",
-                                         grpc::InsecureChannelCredentials());
+  const char* port = std::getenv("AGONES_SDK_GRPC_PORT");
+  pimpl_->host_ = std::string("localhost:") + (port ? port : "59357");
+  pimpl_->channel_ =
+      grpc::CreateChannel(pimpl_->host_, grpc::InsecureChannelCredentials());
 }
 
 SDK::~SDK() {}
@@ -37,6 +40,8 @@ bool SDK::Connect() {
   if (!pimpl_->channel_->WaitForConnected(
           gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
                        gpr_time_from_seconds(30, GPR_TIMESPAN)))) {
+    std::cerr << "Could not connect to the sidecar at " << pimpl_->host_
+              << ".\n";
     return false;
   }