Don't call tail.Cleanup()

It is only supposed to be called from a process exit handler,
and exists as a workaround to a Linux kernel bug that _may_ have
existed in some kernels back in early 2014.

Calling tail.Cleanup() seems to prevent the process from receiving
any further fsnotify notification for the same file again (at least
on macOS).

Signed-off-by: Jan Dubois <[email protected]>

Author: jandubois

pkg/hostagent/events/watcher.go

@@ -22,7 +22,7 @@ func Watch(ctx context.Context, haStdoutPath, haStderrPath string, begin time.Ti
 	}
 	defer func() {
 		_ = haStdoutTail.Stop()
-		haStdoutTail.Cleanup()
+		// Do NOT call haStdoutTail.Cleanup(), it prevents the process from ever tailing the file again
 	}()
 
 	haStderrTail, err := tail.TailFile(haStderrPath,
@@ -35,7 +35,7 @@ func Watch(ctx context.Context, haStdoutPath, haStderrPath string, begin time.Ti
 	}
 	defer func() {
 		_ = haStderrTail.Stop()
-		haStderrTail.Cleanup()
+		// Do NOT call haStderrTail.Cleanup(), it prevents the process from ever tailing the file again
 	}()
 
 loop:

pkg/instance/start.go

@@ -115,7 +115,18 @@ func Prepare(ctx context.Context, inst *store.Instance) (*Prepared, error) {
 	}, nil
 }
 
-// Start starts the instance.
+// Start starts the hostagent in the background, which in turn will start the instance.
+// Start will listen to hostagent events and log them to STDOUT until either the instance
+// is running, or has failed to start.
+//
+// The `limactl` argument allows the caller to specify the full path of the `limactl` executable.
+// When called from inside limactl itself it will always be the empty string which uses the name
+// of the current executable instead.
+//
+// The `launchHostAgentForeground` argument makes the hostagent run in the foreground.
+// The function will continue to listen and log hostagent events until the instance is
+// shut down again.
+//
 // Start calls Prepare by itself, so you do not need to call Prepare manually before calling Start.
 func Start(ctx context.Context, inst *store.Instance, limactl string, launchHostAgentForeground bool) error {
 	haPIDPath := filepath.Join(inst.Dir, filenames.HostAgentPID)