Updates cleanup-containers

Previously cleanup-containers suffered from the following
limitations:

1. The docker rm command would fail if all the containers were not
   stopped.
2. The script would throw an error if no containers existed.
3. Artifacts such as veths, bridges, etc.. would remain on the host
   after containers were removed. These artifacts should be removed
   if the containers are removed.

Change-Id: I5eadb23fec9e34125a32f6c3e39c241d97932910

tools/cleanup-containers

 #!/bin/bash
 
-docker rm $@ $(docker ps -a -q)
+# Check if user is root
+if [[ $EUID -ne 0 ]]; then
+    echo "You must execute this script as root." 1>&2
+    exit 1
+fi
+
+# Move to top level directory
+REAL_PATH=$(python -c "import os,sys;print os.path.realpath('$0')")
+cd "$(dirname "$REAL_PATH")/.."
+
+# Remove docker containers
+docker ps -a -q | while read -r line ; do
+  echo "Removing docker containers"
+  docker rm -f $line
+done
+
+# Spawning the neutron-agents container leaves artifacts on the host.
+# This script removes these artifacts.
+ip netns list | while read -r line ; do
+  echo "Removing network namespaces on the host"
+  ip netns delete $line
+done
+
+ifconfig | grep tap | awk '{print $1;}'| cut -f1 -d':' | while read -r line ; do
+  echo "Removing tap interfaces on the host"
+  ip link delete $line type veth
+done
+
+ifconfig | grep brq | awk '{print $1;}'| cut -f1 -d':' | while read -r line ; do
+  echo "Removing linux bridges on the host"
+  ip link delete $line type bridge
+done
+
+ifconfig | grep vxlan | awk '{print $1;}'| cut -f1 -d':' | while read -r line ; do
+  echo "Removing vxlan interfaces on the host"
+  ip link delete $line type vxlan
+done