Add support for building ovs from git sources on stacking

This eases the deployment of a devstack machine with the latest
Open vSwitch bits, adding this to local.conf provides a fully
featured ovs-ct firewall setup:

  enable_plugin neutron git://git.openstack.org/openstack/neutron

  Q_BUILD_OVS_FROM_GIT=True

  [[post-config|/$Q_PLUGIN_CONF_FILE]]
  [securitygroup]
  firewall_driver = openvswitch

Change-Id: Ia7ad1658b95d7404384c7cae833008a57e3e5af1

devstack/lib/ovs

@@ -65,7 +65,15 @@ function compile_ovs {
 
     if is_fedora ; then
         # is_fedora covers Fedora, RHEL, CentOS, etc...
-        install_package kernel-devel
+        echo NOTE: if kernel-devel-$(uname -r) or kernel-headers-$(uname -r) installation
+        echo failed, please, provide a repository with the package, or yum update / reboot
+        echo your machine to get the latest kernel.
+
+        install_package kernel-devel-$(uname -r)
+        install_package kernel-headers-$(uname -r)
+
+    elif is_ubuntu ; then
+        install_package linux-headers-$(uname -r)
     fi
 
     if [ ! -f configure ] ; then
@@ -94,6 +102,15 @@ function compile_ovs {
 
 # start_new_ovs() - removes old ovs database, creates a new one and starts ovs
 function start_new_ovs () {
-    rm -f /etc/openvswitch/conf.db /etc/openvswitch/.conf.db~lock~
+    sudo rm -f /etc/openvswitch/conf.db /etc/openvswitch/.conf.db~lock~
     sudo /usr/share/openvswitch/scripts/ovs-ctl start
 }
+
+# remove_ovs_packages() - removes old ovs packages from the system
+function remove_ovs_packages() {
+    for package in openvswitch openvswitch-switch openvswitch-common; do
+        if is_package_installed $package; then
+            uninstall_package $package
+        fi
+    done
+}

devstack/plugin.sh

@@ -6,6 +6,9 @@ source $LIBDIR/l2_agent
 source $LIBDIR/l2_agent_sriovnicswitch
 source $LIBDIR/ml2
 source $LIBDIR/qos
+source $LIBDIR/ovs
+
+Q_BUILD_OVS_FROM_GIT=$(trueorfalse False Q_BUILD_OVS_FROM_GIT)
 
 if [[ "$1" == "stack" ]]; then
     case "$2" in
@@ -19,6 +22,12 @@ if [[ "$1" == "stack" ]]; then
             if is_service_enabled q-bgp; then
                 configure_bgp
             fi
+            if [[ "$Q_AGENT" == "openvswitch" ]] && \
+               [[ "$Q_BUILD_OVS_FROM_GIT" == "True" ]]; then
+                remove_ovs_packages
+                compile_ovs True /usr /var
+                start_new_ovs
+            fi
             ;;
         post-config)
             if is_service_enabled q-agt; then

neutron/tests/contrib/gate_hook.sh

@@ -28,11 +28,7 @@ then
         # we use a commit on branch-2.5 that fixes compilation with the
         # latest ubuntu trusty kernel.
         OVS_BRANCH=8c0b419a0b9ac0141d6973dcc80306dfc6a83d31
-        for package in openvswitch openvswitch-switch openvswitch-common; do
+        remove_ovs_packages
-            if is_package_installed $package; then
-                uninstall_package $package
-            fi
-        done
         compile_ovs True /usr /var
         start_new_ovs
     fi