driver/sshdriver: add multifile support to scp

Users are accustomed to scp having an option for copying recursively as
well as to accept multiple source files.
Meet user expectation by adding well known `-r` option and support for
multiple source files.

Author: sbngross

labgrid/driver/sshdriver.py

@@ -356,24 +356,31 @@ def forward_unix_socket(self, unixsocket, localport=None):
             yield localport
 
     @Driver.check_active
-    @step(args=['src', 'dst'])
-    def scp(self, *, src, dst):
+    @step(args=['src', 'dst', 'recursive'])
+    def scp(self, *, src, dst, recursive=False):
         if not self._check_keepalive():
             raise ExecutionError("Keepalive no longer running")
 
-        if src.startswith(':') == dst.startswith(':'):
-            raise ValueError("Either source or destination must be remote (start with :)")
-        if src.startswith(':'):
-            src = '_' + src
-        if dst.startswith(':'):
+        if all([f.startswith(':') for f in src]):
+            if dst.startswith(':'):
+                raise ValueError("Either source or destination must be remote (start with :)")
+            src = ['_' + f for f in src]
+        else:
+            if not dst.startswith(':'):
+                raise ValueError("Either source or destination must be remote (start with :)")
             dst = '_' + dst
 
         complete_cmd = [self._scp,
                 "-S", self._ssh,
                 "-F", "none",
                 "-o", f"ControlPath={self.control.replace('%', '%%')}",
-                src, dst,
+                dst,
         ]
+        for f in src:
+            complete_cmd.insert(-1, f)
+
+        if recursive:
+            complete_cmd.insert(1, "-r")
 
         if self.explicit_sftp_mode and self._scp_supports_explicit_sftp_mode():
             complete_cmd.insert(1, "-s")