cmd: always create Stdin pipe when using a terminal in Start()

conpty has a known race condition when attaching a terminal to a starting
process that does not have a Stdin handle, causing the process to exit
immediately with a 0xc000013a (STATUS_CONTROL_C_EXIT) error. This is easily
noticed when launching a container using nerdctl in detached terminal mode
which uses BinaryIO where only the Stdout and Stderr handles are created for
the target process. Attempting to start a target process in this configuration
results in a process start success rate of less than 5%.

Since the race condition in conpty is unlikely to be fixed in the short
term, add a workaround to ensure that a Stdin handle is always created for
container processes launched with terminal mode enabled. This allows a
container started using nerdctl in detached terminal mode to always start
successfully.

Signed-off-by: Mark Cave-Ayland <mark.caveayland@nutanix.com>

Author: mcayland-ntx

internal/cmd/cmd.go

@@ -180,7 +180,7 @@ func (c *Cmd) Start() error {
 			User:             c.Spec.User.Username,
 			WorkingDirectory: c.Spec.Cwd,
 			EmulateConsole:   c.Spec.Terminal,
-			CreateStdInPipe:  c.Stdin != nil,
+			CreateStdInPipe:  c.Stdin != nil || c.Spec.Terminal,
 			CreateStdOutPipe: c.Stdout != nil,
 			CreateStdErrPipe: c.Stderr != nil,
 		}