Nicira plugin: do not die if NVP gateway IP is missing

Devstack should not die if the IP and prefix len for establishing
a connection to the public network are not provided.
In this case, the public gateway IP address used to configure
Neutron's public network should be used, together with the prefix
length of the public network's CIDR.

This patch also ensures $PUBLIC_BRIDGE is created, even if
Q_USE_DEBUG_COMMAND is disabled. Finally this patch also adds
the teardown operation for restoring the original IP addresses
on the interface used for connectivity to the public network
implemented on the NVP gateway.

Bug #1227750

Change-Id: Ib58738a578c46f2183d503cabfdc6039bfbeb702
baremetal: Allow BM_SECOND_MAC to be unset

Currently DevStack registers the second nic of the baremetal
node even if BM_SECOND_MAC is not set or empty. However
an interface with an empty mac address causes dhcp to fail
(bug 1238595). And such operation will get to return a error
after the bug is resolved. So we should not register the
second nic if BM_SECOND_MAC is not set.

Related-Bug: #1238595
Change-Id: Ib3cc77686b72311403ccacbd70ae9cf43e6eb4c9
remove useless step in cleanup_rpc_backend

It shall not make dir of /var/run/openstack for the cleanup operation.

install_rpc_backend will make the directory, which is covered by another
take care of this.

Change-Id: I2bf1bfb4a6b409cc04f2d7b94dd58627e0134b71
refine rabbit cleanup

Beside it's good to killall -9 epmd,
if killall epmd fails

Change-Id: Ide90ef8ac3339bd70d991666ce0d3550a088670b
Fix false negative, when HEAT_CREATE_TEST_IMAGE is unset

Fix shell variable comparision bug
Closes-Bug: #1239041

Change-Id: Ifbc8545f929eb7bbf9b85df889dfd9fa3a96b7c0
Don't kill ceilometer prematurally in devstackgate

This change ensure that 'ceilometer' processes are not killed
by stack.sh when USE_SCREEN=False

Fixes bug #1234254

Change-Id: I48dbf18ea0b169cdb5295a709d82c025f6fb8930
Merge "Fix false negative, when HEAT_CREATE_TEST_IMAGE is unset"
Merge "refine rabbit cleanup"
Merge "Nicira plugin: do not die if NVP gateway IP is missing"
Merge "baremetal: Allow BM_SECOND_MAC to be unset"
Merge "remove useless step in cleanup_rpc_backend"
Merge "Don't kill ceilometer prematurally in devstackgate"
Create-stack-user script should have execute permissions

Currently running stack.sh as root advises you about this script, which is not
executable

Change-Id: I674af044b8f3c31bcc86be5c6552e8086453d5cd