console: for public errors only print a final one

By default, interactive console prints full traceback in case of an
error. This looks weird in the console when LDAP errors pop up.
Instead, process PublicError exceptions as if they are final ones and
only print their message.

As a result, calls like api.Command.user_show('unknown') would
result in a concise message:

  >>> api.Command.user_show('unknown')
  IPA public error exception: NotFound: unknown: user not found
  >>>

rather than a two-screen long traceback.

Fixes: https://pagure.io/freeipa/issue/9590

Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>

ipalib/cli.py

@@ -957,6 +957,17 @@ class IPACompleter(rlcompleter.Completer):
         return super()._callable_postfix(val, word)
 
 
+class InteractiveConsole(code.InteractiveConsole):
+    def showtraceback(self):
+        ei = sys.exc_info()
+        e = ei[1]
+        if isinstance(e, PublicError):
+            self.write('IPA public error exception: %s: %s\n' %
+                       (e.__class__.__name__, str(e)))
+        else:
+            super().showtraceback()
+
+
 class console(frontend.Command):
     """Start the IPA interactive Python console, or run a script.
 
@@ -1018,13 +1029,14 @@ class console(frontend.Command):
         else:
             if readline is not None:
                 self._setup_tab_completion(local)
-            code.interact(
+            cons = InteractiveConsole(local)
+            cons.interact(
                 "\n".join((
                     "(Custom IPA interactive Python console)",
                     "    api: IPA API object",
                     "    pp: pretty printer",
                 )),
-                local=local
+                exitmsg=None
             )