Workaround: during fab upgrade_contrail, may encounter the failure due to "Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable)" and please remove the file /var/lib/dpkg/lock on all controller nodes and re-issue the command fab upgrade_contrail
Workaround: during fab upgrade_contrail, may encounter the failure due to "Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable)" and please remove the file /var/lib/dpkg/lock on all controller nodes and re-issue the command fab upgrade_contrail