Add better distinction of error cases

Add a new NotFoundError exception for use internally, so we can track
specific failure cases.
Also add a new Error class as a central place to store our error
numbers consistently.
In the API protocol, add a "NOTFOUND" error string alongside "ERROR"
to help the admin interface and other callers distinguish error cases
better.
In the admin interface, actually return distinct non-zero errors in
failure cases. Previously, almost all failures would have returned
suceesfully to the calling shell.

Change-Id: Ie382b737a80b7cd41c551e3a4a2a7e0827260bdc

1 files changed, 13 insertions, 13 deletions

diff --git a/util.py b/util.py
index 25d8d9b..c110380 100644
--- a/util.py
+++ b/util.py
@@ -20,7 +20,7 @@
 
 import logging
 import time
-from errors import CriticalError, InputError, ConfigError, SocketError
+from errors import CriticalError, NotFoundError, InputError, ConfigError, SocketError
 
 class VlanUtil:
     """VLANd utility functions"""
@@ -118,7 +118,7 @@ class VlanUtil:
             else:
                 raise InputError("Unknown db_query command \"%s\"" % command)
 
-        except InputError as e:
+        except (InputError, NotFoundError) as e:
             logging.error('perform_db_query(%s) got error %s', command, e)
             raise
         except ValueError as e:
@@ -152,7 +152,7 @@ class VlanUtil:
             else:
                 raise InputError("Unknown daemon_query command \"%s\"" % command)
 
-        except InputError as e:
+        except (InputError, NotFoundError) as e:
             logging.error('perform_daemon_query(%s) got error %s', command, e)
             raise
         except ValueError as e:
@@ -195,7 +195,7 @@ class VlanUtil:
             else:
                 raise InputError("Unknown db_update command \"%s\"" % command)
 
-        except InputError as e:
+        except (InputError, NotFoundError) as e:
             logging.error('perform_db_update(%s) got error %s', command, e)
             raise
         except ValueError as e:
@@ -230,7 +230,7 @@ class VlanUtil:
             else:
                 raise InputError("Unknown query command \"%s\"" % command)
 
-        except InputError as e:
+        except (InputError, NotFoundError) as e:
             logging.error('perform_vlan_update(%s) got error %s', command, e)
             raise
         except ValueError as e:
@@ -266,7 +266,7 @@ class VlanUtil:
             logging.debug('Adding DB record first: name %s, tag %d, is_base_vlan %d', name, tag, is_base_vlan)
             vlan_id = db.create_vlan(name, tag, is_base_vlan)
             logging.debug('Added VLAN tag %d, name %s to the database, created VLAN ID %d', tag, name, vlan_id)
-        except InputError:
+        except (InputError, NotFoundError):
             logging.debug('DB creation failed')
             raise
 
@@ -371,7 +371,7 @@ class VlanUtil:
         logging.debug('Checking for ports using VLAN ID %d', vlan_id)
         vlan = db.get_vlan_by_id(vlan_id)
         if vlan is None:
-            raise InputError("VLAN ID %d does not exist" % vlan_id)
+            raise NotFoundError("VLAN ID %d does not exist" % vlan_id)
         vlan_tag = vlan.tag
         ports = db.get_ports_by_current_vlan(vlan_id)
         if ports is not None:
@@ -461,7 +461,7 @@ class VlanUtil:
             logging.debug('Removing DB record: VLAN ID %d', vlan_id)
             vlan_id = db.delete_vlan(vlan_id)
             logging.debug('Removed VLAN ID %d from the database OK', vlan_id)
-        except InputError:
+        except (InputError, NotFoundError):
             logging.debug('DB deletion failed')
             raise
 
@@ -491,7 +491,7 @@ class VlanUtil:
             raise InputError("Port mode '%s' is not a valid option: try 'access' or 'trunk'" % mode)
         port = db.get_port_by_id(port_id)
         if port is None:
-            raise InputError("Port ID %d does not exist" % port_id)
+            raise NotFoundError("Port ID %d does not exist" % port_id)
         if port.is_locked:
             raise InputError("Port ID %d is locked" % port_id)
         if mode == 'trunk' and port.is_trunk:
@@ -580,7 +580,7 @@ class VlanUtil:
         # 1. Sanity checks!
         port = db.get_port_by_id(port_id)
         if port is None:
-            raise InputError("Port ID %d does not exist" % port_id)
+            raise NotFoundError("Port ID %d does not exist" % port_id)
         if port.is_locked:
             raise InputError("Port ID %d is locked" % port_id)
         if port.is_trunk:
@@ -588,7 +588,7 @@ class VlanUtil:
 
         vlan = db.get_vlan_by_id(vlan_id)
         if vlan is None:
-            raise InputError("VLAN ID %d does not exist" % vlan_id)
+            raise NotFoundError("VLAN ID %d does not exist" % vlan_id)
 
         # Get the right driver
         switch_name = db.get_switch_name_by_id(port.switch_id)
@@ -640,7 +640,7 @@ class VlanUtil:
         # 1. Sanity checks!
         port = db.get_port_by_id(port_id)
         if port is None:
-            raise InputError("Port ID %d does not exist" % port_id)
+            raise NotFoundError("Port ID %d does not exist" % port_id)
         if port.is_trunk:
             raise InputError("Port ID %d is not an access port" % port_id)
         if port.is_locked:
@@ -708,7 +708,7 @@ class VlanUtil:
             raise InputError("Switch name %s already exists in the DB (ID %d)" % (switch_name, switch_id))
 
         if not switch_name in config.switches:
-            raise InputError("Switch name %s not defined in config" % switch_name)
+            raise NotFoundError("Switch name %s not defined in config" % switch_name)
 
         # 2. Now start reading config from the switch
         try: