[cli] Disable spinner animation on non-live TTYs

Gating the spinner animation logic on the term->cout_is_live() flag.
This prevents messy output (backspaces and animation frames) when
Multipass is run in non-interactive environments.

Author: riken127

src/client/cli/cmd/animated_spinner.cpp

@@ -29,8 +29,8 @@ void clear_line(std::ostream& out)
 }
 } // namespace
 
-mp::AnimatedSpinner::AnimatedSpinner(std::ostream& cout)
-    : spinner{'|', '/', '-', '\\'}, cout{cout}, running{false}
+mp::AnimatedSpinner::AnimatedSpinner(std::ostream& cout, bool is_tty)
+    : spinner{'|', '/', '-', '\\'}, cout{cout}, running{false}, is_tty(is_tty)
 {
 }
 
@@ -46,15 +46,23 @@ void mp::AnimatedSpinner::start(const std::string& start_message)
     {
         current_message = start_message;
         running = true;
-        clear_line(cout);
-        cout << start_message << "  " << std::flush;
-        t = std::thread(&AnimatedSpinner::draw, this);
+
+        if (is_tty)
+        {
+            clear_line(cout);
+            cout << start_message << "  " << std::flush;
+            t = std::thread(&AnimatedSpinner::draw, this);
+        }
+        else
+        {
+            cout << start_message << std::flush;
+        }
     }
 }
 
 void mp::AnimatedSpinner::start()
 {
-    if (!current_message.empty())
+    if (is_tty && !current_message.empty())
         start(current_message);
 }
 
@@ -69,7 +77,9 @@ void mp::AnimatedSpinner::stop()
         if (t.joinable())
             t.join();
     }
-    clear_line(cout);
+
+    if (is_tty)
+        clear_line(cout);
 }
 
 void mp::AnimatedSpinner::print(std::ostream& stream, const std::string& message)
@@ -92,6 +102,5 @@ void mp::AnimatedSpinner::draw()
         cout << "\b" << *it << std::flush;
         cv.wait_for(lock, std::chrono::milliseconds(100));
     }
-    cout << "\b"
-         << " " << std::flush;
+    cout << "\b" << " " << std::flush;
 }

src/client/cli/cmd/animated_spinner.h

@@ -27,7 +27,7 @@ namespace multipass
 class AnimatedSpinner
 {
 public:
-    explicit AnimatedSpinner(std::ostream& cout);
+    explicit AnimatedSpinner(std::ostream& cout, bool is_tty = true);
     ~AnimatedSpinner();
 
     void start(const std::string& message);
@@ -44,5 +44,6 @@ class AnimatedSpinner
     std::mutex mutex;
     std::condition_variable cv;
     std::thread t;
+    const bool is_tty;
 };
 } // namespace multipass

src/client/cli/cmd/clone.cpp

@@ -33,7 +33,7 @@ mp::ReturnCodeVariant cmd::Clone::run(ArgParser* parser)
         return parser->returnCodeFrom(parscode);
     }
 
-    AnimatedSpinner spinner{cout};
+    AnimatedSpinner spinner{cout, term->cout_is_live()};
     auto action_on_success = [this, &spinner](CloneReply& reply) -> ReturnCodeVariant {
         spinner.stop();
         cout << reply.reply_message();

src/client/cli/cmd/launch.cpp

@@ -468,7 +468,7 @@ mp::ReturnCodeVariant cmd::Launch::request_launch(const ArgParser* parser)
 {
     if (!spinner)
         spinner = std::make_unique<multipass::AnimatedSpinner>(
-            cout); // Creating just in time to work around canonical/multipass#2075
+            cout, term->cout_is_live()); // Creating just in time to work around canonical/multipass#2075
 
     if (timer)
         timer->resume();

src/client/cli/cmd/mount.cpp

@@ -78,7 +78,7 @@ mp::ReturnCodeVariant cmd::Mount::run(mp::ArgParser* parser)
         return parser->returnCodeFrom(ret);
     }
 
-    mp::AnimatedSpinner spinner{cout};
+    mp::AnimatedSpinner spinner{cout, term->cout_is_live()};
 
     auto on_success = [&spinner](mp::MountReply& reply) -> ReturnCodeVariant {
         spinner.stop();

src/client/cli/cmd/restart.cpp

@@ -38,7 +38,7 @@ mp::ReturnCodeVariant cmd::Restart::run(mp::ArgParser* parser)
     if (ret != ParseCode::Ok)
         return parser->returnCodeFrom(ret);
 
-    AnimatedSpinner spinner{cout};
+    AnimatedSpinner spinner{cout, term->cout_is_live()};
     auto on_success = [this, &spinner](mp::RestartReply& reply) -> ReturnCodeVariant {
         spinner.stop();
         if (term->is_live() && update_available(reply.update_info()))

src/client/cli/cmd/restore.cpp

@@ -31,7 +31,7 @@ mp::ReturnCodeVariant cmd::Restore::run(mp::ArgParser* parser)
     if (auto ret = parse_args(parser); ret != ParseCode::Ok)
         return parser->returnCodeFrom(ret);
 
-    AnimatedSpinner spinner{cout};
+    AnimatedSpinner spinner{cout, term->cout_is_live()};
 
     auto on_success = [this, &spinner](mp::RestoreReply& reply) -> ReturnCodeVariant {
         spinner.stop();

src/client/cli/cmd/snapshot.cpp

@@ -31,7 +31,7 @@ mp::ReturnCodeVariant cmd::Snapshot::run(mp::ArgParser* parser)
     if (auto ret = parse_args(parser); ret != ParseCode::Ok)
         return parser->returnCodeFrom(ret);
 
-    AnimatedSpinner spinner{cout};
+    AnimatedSpinner spinner{cout, term->cout_is_live()};
 
     auto on_success = [this, &spinner](mp::SnapshotReply& reply) -> ReturnCodeVariant {
         spinner.stop();

src/client/cli/cmd/start.cpp

@@ -55,7 +55,7 @@ mp::ReturnCodeVariant cmd::Start::run(mp::ArgParser* parser)
         return parser->returnCodeFrom(ret);
     }
 
-    AnimatedSpinner spinner{cout};
+    AnimatedSpinner spinner{cout, term->cout_is_live()};
 
     auto on_success = [&spinner, this](mp::StartReply& reply) -> ReturnCodeVariant {
         spinner.stop();

src/client/cli/cmd/stop.cpp

@@ -39,7 +39,7 @@ mp::ReturnCodeVariant cmd::Stop::run(mp::ArgParser* parser)
 
     auto on_success = [](mp::StopReply& reply) -> ReturnCodeVariant { return ReturnCode::Ok; };
 
-    AnimatedSpinner spinner{cout};
+    AnimatedSpinner spinner{cout, term->cout_is_live()};
     auto on_failure = [this, &spinner](grpc::Status& status) -> ReturnCodeVariant {
         spinner.stop();