fix: Monitor TTY size when using SSH (#1119)

The TTY wasn't resizing properly, and reasonably so considering
we weren't updating it 🤦.

cli/ssh.go

@@ -134,6 +134,19 @@ func ssh() *cobra.Command {
 				defer func() {
 					_ = term.Restore(int(os.Stdin.Fd()), state)
 				}()
+
+				windowChange := listenWindowSize(cmd.Context())
+				go func() {
+					for {
+						select {
+						case <-cmd.Context().Done():
+							return
+						case <-windowChange:
+						}
+						width, height, _ := term.GetSize(int(stdoutFile.Fd()))
+						_ = sshSession.WindowChange(height, width)
+					}
+				}()
 			}
 
 			err = sshSession.RequestPty("xterm-256color", 128, 128, gossh.TerminalModes{})

cli/ssh_other.go

@@ -0,0 +1,22 @@
+//go:build !windows
+// +build !windows
+
+package cli
+
+import (
+	"context"
+	"os"
+	"os/signal"
+
+	"golang.org/x/sys/unix"
+)
+
+func listenWindowSize(ctx context.Context) <-chan os.Signal {
+	windowSize := make(chan os.Signal, 1)
+	signal.Notify(windowSize, unix.SIGWINCH)
+	go func() {
+		<-ctx.Done()
+		signal.Stop(windowSize)
+	}()
+	return windowSize
+}

cli/ssh_windows.go

@@ -0,0 +1,27 @@
+//go:build windows
+// +build windows
+
+package cli
+
+import (
+	"context"
+	"os"
+	"time"
+)
+
+func listenWindowSize(ctx context.Context) <-chan os.Signal {
+	windowSize := make(chan os.Signal, 3)
+	ticker := time.NewTicker(time.Second)
+	go func() {
+		defer ticker.Stop()
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case <-ticker.C:
+			}
+			windowSize <- nil
+		}
+	}()
+	return windowSize
+}