From feb6452857669cd2ef85bfcdd4cf6576a7f464e5 Mon Sep 17 00:00:00 2001
From: Steve McIntyre <steve.mcintyre@linaro.org>
Date: Fri, 19 Dec 2014 18:53:02 +0000
Subject: Implemented the backend for delete_vlan()

Change-Id: Ie70408c6ce52e8a520df86c77194a96ae196ef89
---
 util.py | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)

diff --git a/util.py b/util.py
index 1d1a935..7652037 100644
--- a/util.py
+++ b/util.py
@@ -291,3 +291,113 @@ class VlanUtil:
 
         return vlan_id # If we're successful
 
+    # Complex call
+    # 1. Check in the DB if there are any ports on the VLAN. Bail if so
+    # 2. Iterate through all switches:
+    #    a. Remove the VLAN from all trunk ports (if needed)
+    #    b. Remove the VLAN
+    # 3. If all went OK, save config on the switches
+    # 4. Remove the VLAN in the DB
+    #
+    # If things fail, we attempt to roll back by rebooting switches.
+    def delete_vlan(self, state, command, data):
+
+        print 'delete_vlan'
+        db = state.db
+        config = state.config
+
+        vlan_id = int(data['vlan_id'])
+
+        # 1. Check for database records first
+        print '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)
+        vlan_tag = vlan.tag
+        ports = db.get_ports_by_current_vlan(vlan_id)
+        if ports is not None:
+            raise InputError("Cannot delete VLAN ID %d when it still has %d ports" %
+                             (vlan_id, len(ports)))
+        ports = db.get_ports_by_base_vlan(vlan_id)
+        if ports is not None:
+            raise InputError("Cannot delete VLAN ID %d when it still has %d ports" %
+                             (vlan_id, len(ports)))
+
+        # Keep track of which switches we've configured, for later use
+        switches_done = []
+
+        # 2. Now the switches
+        try:
+            for switch in sorted(config.switches):
+                trunk_ports = []
+                try:
+                    # Get the right driver
+                    s = self.get_switch_driver(switch, config)
+                    s.switch_connect(config.switches[switch].username, config.switches[switch].password)
+
+                    # Mark this switch as one we've touched, for
+                    # either config saving or rollback below
+                    switches_done.append(switch)
+
+                    # 2a. Do we need to worry about trunk ports on this switch?
+                    if 'TrunkWildCardVlans' in s.switch_get_capabilities():
+                        print 'This switch does not need special trunk port handling'
+                    else:
+                        print 'This switch needs special trunk port handling'
+                        switch_id = db.get_switch_id_by_name(switch)
+                        trunk_ports = db.get_trunk_port_names_by_switch(switch_id)
+                        if trunk_ports is None:
+                            print "But it has no trunk ports defined"
+                            trunk_ports = []
+                        else:
+                            print 'Found %d trunk_ports that need adjusting' % len(trunk_ports)
+
+                    # Modify any trunk ports as needed
+                    for port in trunk_ports:
+                        s.port_remove_trunk_from_vlan(port, tag)
+                        print 'Removed VLAN tag %d from switch %s port %s' % (vlan_tag, switch, port)
+
+                    # 2b. Remove the VLAN from the switch
+                    print 'Removing VLAN tag %d from switch %s' % (vlan_tag, switch)
+                    s.vlan_destroy(vlan_tag)
+                    print 'Removed VLAN tag %d from switch %s' % (vlan_tag, switch)
+
+                    # And now we're done with this switch
+                    s.switch_disconnect()
+                    del s
+
+                except IOError:
+                    raise
+
+        except IOError:
+            # Bugger. Looks like one of the switch calls above
+            # failed. To undo the changes safely, we'll need to reset
+            # all the switches we managed to configure. This could
+            # take some time!
+            for switch in switches_done:
+                s = self.get_switch_driver(switch, config)
+                s.switch_connect(config.switches[switch].username, config.switches[switch].password)
+                s.switch_restart() # Will implicitly also close the connection
+                del s
+
+        # 3. If we've got this far, things were successful. Save
+        # config on all the switches so it will persist across reboots
+        for switch in switches_done:
+            s = self.get_switch_driver(switch, config)
+            s.switch_connect(config.switches[switch].username, config.switches[switch].password)
+            s.switch_save_running_config()
+            s.switch_disconnect()
+            del s
+
+        # 4. Finally, remove the VLAN in the DB
+        try:
+            print 'Removing DB record: VLAN id %d' % vlan_id
+            vlan_id = db.delete_vlan(vlan_id)
+            print 'Removed VLAN id %d from the database OK' % vlan_id
+        except InputError:
+            print 'DB deletion failed'
+            raise
+
+        return vlan_id # If we're successful
+
+
-- 
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