ssh kitten: Allow configuring the ssh kitten to skip some hosts via a new delegate config directive

Author: kovidgoyal

docs/changelog.rst

@@ -71,6 +71,8 @@ Detailed list of changes
 
 - ssh kitten: Fix a regression in 0.28.0 that caused interrupt during setup to not be handled gracefully (:iss:`6254`)
 
+- ssh kitten: Allow configuring the ssh kitten to skip some hosts via a new ``delegate`` config directive
+
 - Graphics: Move images up along with text when the window is shrunk vertically (:iss:`6278`)
 
 - Fix a regression in 0.28.0 that caused a buffer overflow when clearing the screen (:iss:`6306`, :pull:`6308`)

kittens/ssh/main.go

@@ -32,6 +32,7 @@ import (
 	"kitty/tools/tui/loop"
 	"kitty/tools/utils"
 	"kitty/tools/utils/secrets"
+	"kitty/tools/utils/shlex"
 	"kitty/tools/utils/shm"
 
 	"golang.org/x/exp/maps"
@@ -613,6 +614,13 @@ func run_ssh(ssh_args, server_args, found_extra_args []string) (rc int, err erro
 			fmt.Fprintf(os.Stderr, "Ignoring bad config line: %s:%d with error: %s", filepath.Base(x.Src_file), x.Line_number, x.Err)
 		}
 	}
+	if host_opts.Delegate != "" {
+		delegate_cmd, err := shlex.Split(host_opts.Delegate)
+		if err != nil {
+			return 1, fmt.Errorf("Could not parse delegate command: %#v with error: %w", host_opts.Delegate, err)
+		}
+		return 1, unix.Exec(utils.FindExe(delegate_cmd[0]), utils.Concat(delegate_cmd, ssh_args, server_args), os.Environ())
+	}
 	if host_opts.Share_connections {
 		kpid, err := strconv.Atoi(os.Getenv("KITTY_PID"))
 		if err != nil {

kittens/ssh/main.py

@@ -201,6 +201,13 @@ def option_text() -> str:
 terminal to send data without an extra roundtrip, adding to initial connection
 latency.
 ''')
+
+opt('delegate', '', long_text='''
+Do not use the SSH kitten for this host. Instead run the command specified as the delegate.
+For example using :code:`delegate ssh` will run the ssh command with all arguments passed
+to the kitten, except kitten specific ones. This is useful if some hosts are not capable
+of supporting the ssh kitten.
+''')
 egr()  # }}}