ShellDriver: add optional arg dest_authorized_keys

Add an addition optional arg "dest_authorized_keys" with the default
value of ```~/.ssh/authorized_keys```,

An example where this might be used is when an embedded system uses
dropbear as it's ssh server daemon.  In such a case, the authorized_keys
file is ```/etc/dropbear/authorized_keys```

Additionally, the ```put_key_file``` takes an optional
```dest_authorized_keys``` function parameter which defaults to the above arg.

Fixes: ##1626

Signed-off-by: Perry Melange <[email protected]>

Author: pmelange

doc/configuration.rst

@@ -1796,6 +1796,8 @@ Arguments:
     Can be an empty string.
   - keyfile (str): optional, keyfile to upload after login, making the
     `SSHDriver`_ usable
+  - dest_authorized_keys (str): optional, default="~/.ssh/authorized_keys", 
+    filename of the authorized_keys file
   - login_timeout (int, default=60): timeout for login prompt detection in
     seconds
   - await_login_timeout (int, default=2): time in seconds of silence that needs

labgrid/driver/shelldriver.py

@@ -1,6 +1,7 @@
 # pylint: disable=unused-argument
 """The ShellDriver provides the CommandProtocol, ConsoleProtocol and
  InfoProtocol on top of a SerialPort."""
+import os
 import io
 import re
 import shlex
@@ -34,6 +35,7 @@ class ShellDriver(CommandMixin, Driver, CommandProtocol, FileTransferProtocol):
         username (str): username to login with
         password (str): password to login with
         keyfile (str): keyfile to bind mount over users authorized keys
+        dest_authorized_keys (str): optional, default="~/.ssh/authorized_keys", filename of the authorized_keys file
         login_timeout (int): optional, timeout for login prompt detection
         console_ready (regex): optional, pattern used by the kernel to inform the user that a
             console can be activated by pressing enter.
@@ -49,6 +51,7 @@ class ShellDriver(CommandMixin, Driver, CommandProtocol, FileTransferProtocol):
     username = attr.ib(validator=attr.validators.instance_of(str))
     password = attr.ib(default=None, validator=attr.validators.optional(attr.validators.instance_of(str)))
     keyfile = attr.ib(default="", validator=attr.validators.instance_of(str))
+    dest_authorized_keys = attr.ib(default="~/.ssh/authorized_keys", validator=attr.validators.instance_of(str))
     login_timeout = attr.ib(default=60, validator=attr.validators.instance_of(int))
     console_ready = attr.ib(default="", validator=attr.validators.instance_of(str))
     await_login_timeout = attr.ib(default=2, validator=attr.validators.instance_of(int))
@@ -72,7 +75,7 @@ def on_activate(self):
             if self.target.env:
                 keyfile_path = self.target.env.config.resolve_path(self.keyfile)
 
-            self._put_ssh_key(keyfile_path)
+            self._put_ssh_key(keyfile_path, self.dest_authorized_keys)
 
     def on_deactivate(self):
         self._status = 0
@@ -217,8 +220,8 @@ def _write_key(self, keyline, dest):
             self._run_check(f'echo -n "{part}" >> {dest}')
         self._run_check(f'echo "" >> {dest}')
 
-    @step(args=['keyfile_path'])
-    def _put_ssh_key(self, keyfile_path):
+    @step(args=['keyfile_path', 'dest_authorized_keys'])
+    def _put_ssh_key(self, keyfile_path, dest_authorized_keys):
         """Upload an SSH Key to a target"""
         regex = re.compile(
             r"""ssh-(rsa|ed25519)
@@ -236,7 +239,8 @@ def _put_ssh_key(self, keyfile_path):
                     f"Could not parse SSH-Key from file: {keyfile}"
                 )
         self.logger.debug("Read Key: %s", new_key)
-        auth_keys, _, read_keys = self._run("cat ~/.ssh/authorized_keys")
+        dest_authorized_keys_dir = os.path.dirname(dest_authorized_keys)
+        auth_keys, _, read_keys = self._run(f"""cat {self.dest_authorized_keys}""")
         self.logger.debug("Exitcode trying to read keys: %s, keys: %s", read_keys, auth_keys)
         result = []
         _, _, test_write = self._run("touch ~/.test")
@@ -258,35 +262,37 @@ def _put_ssh_key(self, keyfile_path):
 
         if test_write == 0 and read_keys == 0:
             self.logger.debug("Key not on target and writeable, concatenating...")
-            self._write_key(keyline, "~/.ssh/authorized_keys")
+            self._write_key(keyline, dest_authorized_keys)
             self._run_check("rm ~/.test")
             return
 
         if test_write == 0:
-            self.logger.debug("Key not on target, testing for .ssh directory")
-            _, _, ssh_dir = self._run("[ -d ~/.ssh/ ]")
+            self.logger.debug("Key not on target, testing for % directory", dest_authorized_keys_dir)
+            _, _, ssh_dir = self._run(f"""[ -d {dest_authorized_keys_dir} ]""")
             if ssh_dir != 0:
-                self.logger.debug("~/.ssh did not exist, creating")
-                self._run("mkdir ~/.ssh/")
-            self._run_check("chmod 700 ~/.ssh/")
-            self.logger.debug("Creating ~/.ssh/authorized_keys")
-            self._run_check("touch ~/.ssh/authorized_keys")
-            self._write_key(keyline, "~/.ssh/authorized_keys")
+                self.logger.debug(" % did not exits, creating", dest_authorized_keys_dir)
+                self._run(f"""mkdir -p {dest_authorized_keys_dir}""")
+            self._run_check(f"""chmod 700 {dest_authorized_keys_dir}""")
+            self.logger.debug("Creating %", dest_authorized_keys)
+            self._write_key(keyline, dest_authorized_keys)
             self._run_check("rm ~/.test")
             return
 
         self.logger.debug("Key not on target and not writeable, using bind mount...")
         self._run_check('mkdir -p -m 700 /tmp/labgrid-ssh/')
-        self._run("cp -a ~/.ssh/* /tmp/labgrid-ssh/")
+        self._run(f"""cp -a {dest_authorized_keys_dir}/* /tmp/labgrid-ssh/""")
         self._write_key(keyline, "/tmp/labgrid-ssh/authorized_keys")
         self._run_check('chmod 600 /tmp/labgrid-ssh/authorized_keys')
-        out, err, exitcode = self._run('mount --bind /tmp/labgrid-ssh/ ~/.ssh/')
+        out, err, exitcode = self._run(f"""mount --bind /tmp/labgrid-ssh/ {dest_authorized_keys_dir}""")
         if exitcode != 0:
-            self.logger.warning("Could not bind mount ~/.ssh directory: %s %s", out, err)
+            self.logger.warning("Could not bind mount % directory: % %", 
+                                dest_authorized_keys_dir, out, err)
 
     @Driver.check_active
-    def put_ssh_key(self, keyfile_path):
-        self._put_ssh_key(keyfile_path)
+    def put_ssh_key(self, keyfile_path, dest_authorized_keys = None):
+        if dest_authorized_keys is None:
+            dest_authorized_keys = self.dest_authorized_keys
+        self._put_ssh_key(keyfile_path, dest_authorized_keys)
 
     def _xmodem_getc(self, size, timeout=10):
         """ called by the xmodem.XMODEM instance to read protocol data from the console """