virtme-ng: introduce --console and --ssh shortcuts

Simplify the remote console and ssh options for the vng front-end:

 - to start a console or ssh server:
   $ vng --console [PORT]
   $ vng --ssh [PORT]

 - to start a console or ssh client session:
   $ vng --console-client [PORT]
   $ vng --ssh-client [PORT]

Signed-off-by: Andrea Righi <arighi@nvidia.com>

Author: arighi

README.md

@@ -129,8 +129,12 @@ Requirements
  * Optionally, you may need virtiofsd 1.7.0 (or higher) for better filesystem
    performance inside the virtme-ng guests.
 
- * Optionally, you may need `socat` for the `--server` and `--client` options,
-   and the host's kernel should support VSOCK (`CONFIG_VHOST_VSOCK`).
+ * Optionally, you may need `socat` for the `--console` and
+   `--console-client` options, and the host's kernel should support VSOCK
+   (`CONFIG_VHOST_VSOCK`).
+
+ * Optionally, you may need `sshd` installed for the `--ssh` and
+   `--ssh-client` options.
 
 Examples
 ========
@@ -382,26 +386,26 @@ Examples
  - Connect to a simple remote shell (`socat` is required, VSOCK will be used):
 ```
    # Start the vng instance with server support:
-   $ vng --server
+   $ vng --console
 
    # In a separate terminal run the following command to connect to a remote shell:
-   $ vng --client
+   $ vng --console-client
 ```
 
  - Enable ssh in the vng guest:
 ```
    # Start the vng instance with ssh server support:
-   $ vng --server ssh
+   $ vng --ssh
 
    # Connect to the vng guest from the host via ssh:
-   $ vng --client ssh
+   $ vng --ssh-client
 ```
 
  - Generate some results inside the vng guest and copy them back to the
    host using scp:
 ```
    # Start the vng instance with SSH server support:
-   arighi@host~> vng --server ssh
+   arighi@host~> vng --ssh
    ...
    arighi@virtme-ng~> ./run.sh > result.txt
 

virtme_ng/run.py

@@ -487,32 +487,46 @@ def make_parser():
     )
 
     g_remote = parser.add_argument_group(title="Remote Console")
-    cli_srv_choices = ["console", "ssh"]
 
     g_remote.add_argument(
-        "--server",
+        "--console",
         action="store",
-        const=cli_srv_choices[0],
         nargs="?",
-        choices=cli_srv_choices,
-        help="Enable a server to communicate later from the host to the device using '--client'. "
+        type=int,
+        const=2222,
+        metavar="PORT",
+        help="Enable a server to communicate later from the host using '--console-client'. "
         + "By default, a simple console will be offered using a VSOCK connection, and 'socat' for the proxy."
     )
 
     g_remote.add_argument(
-        "--client",
+        "--console-client",
         action="store",
-        const=cli_srv_choices[0],
         nargs="?",
-        choices=cli_srv_choices,
-        help="Connect to a VM launched with the '--server' option for a remote control.",
+        type=int,
+        const=2222,
+        metavar="PORT",
+        help="Connect to a VM launched with the '--console' option for a remote control.",
     )
 
     g_remote.add_argument(
-        "--port",
+        "--ssh",
         action="store",
+        nargs="?",
         type=int,
-        help="Unique port to communicate with a VM.",
+        const=2222,
+        metavar="PORT",
+        help="Enable SSH server to communicate later from the host to using '--ssh-client'."
+    )
+
+    g_remote.add_argument(
+        "--ssh-client",
+        action="store",
+        nargs="?",
+        type=int,
+        const=2222,
+        metavar="PORT",
+        help="Connect to a VM launched with the '--ssh' option for a remote control.",
     )
 
     g_remote.add_argument(
@@ -992,23 +1006,41 @@ def _get_virtme_net_mac_address(self, args):
         else:
             self.virtme_param["net_mac_address"] = ""
 
-    def _get_virtme_server(self, args):
-        if args.server is not None:
-            self.virtme_param["server"] = "--server " + args.server
+    def _get_virtme_console(self, args):
+        if args.console is not None:
+            self.virtme_param["console"] = f"--server console --port {args.console}"
         else:
-            self.virtme_param["server"] = ""
+            self.virtme_param["console"] = ""
 
-    def _get_virtme_client(self, args):
-        if args.client is not None:
-            self.virtme_param["client"] = "--client " + args.client
+    def _get_virtme_console_client(self, args):
+        if args.console_client is not None:
+            self.virtme_param["console_client"] = f"--client console --port {args.console_client}"
         else:
-            self.virtme_param["client"] = ""
+            self.virtme_param["console_client"] = ""
+
+    def _get_virtme_ssh(self, args):
+        if args.console is not None and args.ssh is not None:
+            arg_fail('--console cannot be used with --ssh', show_usage=False)
+
+        if args.ssh is not None and args.root is not None:
+            arg_fail('--ssh is not currently compatible with --root', show_usage=False)
+
+        if args.ssh is not None and args.rw:
+            arg_fail('--ssh is not currently compatible with --rw', show_usage=False)
+
+        if args.ssh is not None:
+            self.virtme_param["ssh"] = f"--server ssh --port {args.ssh}"
+        else:
+            self.virtme_param["ssh"] = ""
+
+    def _get_virtme_ssh_client(self, args):
+        if args.console_client is not None and args.ssh_client is not None:
+            arg_fail('--console-client cannot be used with --ssh-client', show_usage=False)
 
-    def _get_virtme_port(self, args):
-        if args.port is not None:
-            self.virtme_param["port"] = "--port " + str(args.port)
+        if args.ssh_client is not None:
+            self.virtme_param["ssh_client"] = f"--client ssh --port {args.ssh_client}"
         else:
-            self.virtme_param["port"] = ""
+            self.virtme_param["ssh_client"] = ""
 
     def _get_virtme_remote_cmd(self, args):
         if args.remote_cmd is not None:
@@ -1190,9 +1222,10 @@ def run(self, args):
         self._get_virtme_mods(args)
         self._get_virtme_network(args)
         self._get_virtme_net_mac_address(args)
-        self._get_virtme_server(args)
-        self._get_virtme_client(args)
-        self._get_virtme_port(args)
+        self._get_virtme_console(args)
+        self._get_virtme_console_client(args)
+        self._get_virtme_ssh(args)
+        self._get_virtme_ssh_client(args)
         self._get_virtme_remote_cmd(args)
         self._get_virtme_disk(args)
         self._get_virtme_sound(args)
@@ -1234,9 +1267,10 @@ def run(self, args):
             + f'{self.virtme_param["mods"]} '
             + f'{self.virtme_param["network"]} '
             + f'{self.virtme_param["net_mac_address"]} '
-            + f'{self.virtme_param["server"]} '
-            + f'{self.virtme_param["client"]} '
-            + f'{self.virtme_param["port"]} '
+            + f'{self.virtme_param["console"]} '
+            + f'{self.virtme_param["console_client"]} '
+            + f'{self.virtme_param["ssh"]} '
+            + f'{self.virtme_param["ssh_client"]} '
             + f'{self.virtme_param["remote_cmd"]} '
             + f'{self.virtme_param["disk"]} '
             + f'{self.virtme_param["sound"]} '