remote/client: Split _check_allowed() into two methods

It is useful to be able to see if a place is allowed without raising an
error and needing a try...except block. Add a function to handle this
and update _check_allowed() to use it.

This will be used by the updated terminal suport.

Signed-off-by: Simon Glass <sjg@chromium.org>

Author: sjg20

labgrid/remote/client.py

@@ -468,19 +468,28 @@ def _match_places(self, pattern):
                     result.add(name)
         return list(result)
 
-    def _check_allowed(self, place):
+    def is_allowed(self, place):
+        """Check if a place is acquired
+
+        Args:
+            place (str): Place name to check
+
+        Returns:
+            str: None if acquired, else error message
+        """
         if not place.acquired:
-            raise UserError(f"place {place.name} is not acquired")
+            return f"place {place.name} is not acquired"
         if f"{self.gethostname()}/{self.getuser()}" not in place.allowed:
             host, user = place.acquired.split("/")
             if user != self.getuser():
-                raise UserError(
-                    f"place {place.name} is not acquired by your user, acquired by {user}. To work simultaneously, {user} can execute labgrid-client -p {place.name} allow {self.gethostname()}/{self.getuser()}"
-                )
+                return f"place {place.name} is not acquired by your user, acquired by {user}. To work simultaneously, {user} can execute labgrid-client -p {place.name} allow {self.gethostname()}/{self.getuser()}"
             if host != self.gethostname():
-                raise UserError(
-                    f"place {place.name} is not acquired on this computer, acquired on {host}. To allow this host, use labgrid-client -p {place.name} allow {self.gethostname()}/{self.getuser()} on the other host"
-                )
+                return f"place {place.name} is not acquired on this computer, acquired on {host}. To allow this host, use labgrid-client -p {place.name} allow {self.gethostname()}/{self.getuser()} on the other host"
+
+    def _check_allowed(self, place):
+        err = self.is_allowed(place)
+        if err:
+            raise UserError(err)
 
     def get_place(self, place=None):
         pattern = place or self.args.place