Replace deprecated brctl with ip commands

The bridge-utils package has been deprecated for some time now [1] and
'brctl' does not exist on some more recent distros like Fedora 28.
Replace references to brctl with the proper ip commands.

Calls to "brctl show" are not being replaced with calls to "bridge link"
because the output format is very different and in testing some bridges
were not listed.  So the simpler method of consulting /sys/class/net is
used.

In worlddump.py we try running both because failures are handled
gracefully by _dump_cmd(), as well as "ip link show type bridge" for
additional info.

[1] https://lwn.net/Articles/703776/ for example

Change-Id: Ie4c8ad6ce4a09c38023c9e4ec7834c249403145f
Partial-Bug: #1801919

doc/source/guides/multinode-lab.rst

@@ -369,17 +369,6 @@ To pull glance, OpenStack Image service, from an experimental fork:
 Notes stuff you might need to know
 ==================================
 
-Reset the Bridge
-----------------
-
-How to reset the bridge configuration:
-
-::
-
-    sudo brctl delif br100 eth0.926
-    sudo ip link set dev br100 down
-    sudo brctl delbr br100
-
 Set MySQL Password
 ------------------
 

lib/neutron_plugins/linuxbridge_agent

@@ -8,21 +8,23 @@ _XTRACE_NEUTRON_LB=$(set +o | grep xtrace)
 set +o xtrace
 
 function neutron_lb_cleanup {
-    sudo ip link set $PUBLIC_BRIDGE down
-    sudo brctl delbr $PUBLIC_BRIDGE
+    sudo ip link delete $PUBLIC_BRIDGE
 
+    bridge_list=`ls /sys/class/net/*/bridge/bridge_id 2>/dev/null | cut -f5 -d/`
+    if [[ -z "$bridge_list" ]]; then
+        return
+    fi
     if [[ "$Q_ML2_TENANT_NETWORK_TYPE" = "vxlan" ]]; then
-        for port in $(sudo brctl show | grep -o -e [a-zA-Z\-]*tap[0-9a-f\-]* -e vxlan-[0-9a-f\-]*); do
+        for port in $(echo $bridge_list | grep -o -e [a-zA-Z\-]*tap[0-9a-f\-]* -e vxlan-[0-9a-f\-]*); do
             sudo ip link delete $port
         done
     elif [[ "$Q_ML2_TENANT_NETWORK_TYPE" = "vlan" ]]; then
-        for port in $(sudo brctl show | grep -o -e [a-zA-Z\-]*tap[0-9a-f\-]* -e ${LB_PHYSICAL_INTERFACE}\.[0-9a-f\-]*); do
+        for port in $(echo $bridge_list | grep -o -e [a-zA-Z\-]*tap[0-9a-f\-]* -e ${LB_PHYSICAL_INTERFACE}\.[0-9a-f\-]*); do
             sudo ip link delete $port
         done
     fi
-    for bridge in $(sudo brctl show |grep -o -e brq[0-9a-f\-]*); do
-        sudo ip link set $bridge down
-        sudo brctl delbr $bridge
+    for bridge in $(echo $bridge_list |grep -o -e brq[0-9a-f\-]*); do
+        sudo ip link delete $bridge
     done
 }
 

tools/worlddump.py

@@ -163,7 +163,9 @@ def _netns_list():
 def network_dump():
     _header("Network Dump")
 
+    _dump_cmd("bridge link")
     _dump_cmd("brctl show")
+    _dump_cmd("ip link show type bridge")
     ip_cmds = ["neigh", "addr", "link", "route"]
     for cmd in ip_cmds + ['netns']:
         _dump_cmd("ip %s" % cmd)