[cdc_stream] Add a CLI client to start/stop asset streaming sessions (#4)

Implements the cdc_stream client and adjusts asset streaming in
various places to work better outside of a GGP environment.

This CL tries to get quoting for SSH commands right. It also brings
back the ability to start a streaming session from
asset_stream_manager.

Also cleans up Bazel targets setup. Since the sln file is now in root,
it is no longer necessary to prepend ../ to relative filenames to
make clicking on errors work.

cdc_stream/local_assets_stream_manager_client.h

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ASSET_STREAM_MANAGER_LOCAL_ASSETS_STREAM_MANAGER_CLIENT_H_
+#define ASSET_STREAM_MANAGER_LOCAL_ASSETS_STREAM_MANAGER_CLIENT_H_
+
+#include <memory>
+
+#include "absl/status/status.h"
+#include "grpcpp/channel.h"
+#include "proto/local_assets_stream_manager.grpc.pb.h"
+
+namespace grpc_impl {
+class Channel;
+}
+
+namespace cdc_ft {
+
+// gRpc client for starting/stopping asset streaming sessions.
+class LocalAssetsStreamManagerClient {
+ public:
+  // |channel| is a grpc channel to use.
+  explicit LocalAssetsStreamManagerClient(
+      std::shared_ptr<grpc::Channel> channel);
+  ~LocalAssetsStreamManagerClient();
+
+  // Starts streaming the Windows directory |src_dir| to the Linux target
+  // |user_host_dir|, which must be formatted as [user@]host:dir, e.g.
+  // jdoe@jdoe.corp.foo.com:~/assets
+  // Starting a second session to the same target will stop the first one.
+  absl::Status StartSession(const std::string& src_dir,
+                            const std::string& user_host, uint16_t ssh_port,
+                            const std::string& mount_dir,
+                            const std::string& ssh_command,
+                            const std::string& scp_command);
+
+  // Stops the streaming session to the Linux target |user_host_dir|, which must
+  // be formatted as [user@]host:dir, e.g. jdoe@jdoe.corp.foo.com:~/assets
+  absl::Status StopSession(const std::string& user_host_dir,
+                           const std::string& mount_dir);
+
+ private:
+  using LocalAssetsStreamManager =
+      localassetsstreammanager::LocalAssetsStreamManager;
+  std::unique_ptr<LocalAssetsStreamManager::Stub> stub_;
+};
+
+}  // namespace cdc_ft
+
+#endif  // ASSET_STREAM_MANAGER_LOCAL_ASSETS_STREAM_MANAGER_CLIENT_H_