Install OVS from source when it was configured like that

Function _neutron_ovs_base_install_agent_packages always tried to
install openvswitch from packages and start it using systemd units.
That was failing when ovs was expected to be installed from source.
This patch fixes that.

Change-Id: Iae8625dd800d30061ea3dbed9eb0dfbe16f21572
diff --git a/lib/neutron_plugins/ovn_agent b/lib/neutron_plugins/ovn_agent
index 1f737fb..c0bba2c 100644
--- a/lib/neutron_plugins/ovn_agent
+++ b/lib/neutron_plugins/ovn_agent
@@ -24,11 +24,6 @@
 # Load devstack ovs compliation and loading functions
 source ${TOP_DIR}/lib/neutron_plugins/ovs_source
 
-# Defaults
-# --------
-
-Q_BUILD_OVS_FROM_GIT=$(trueorfalse True Q_BUILD_OVS_FROM_GIT)
-
 # Set variables for building OVN from source
 OVN_REPO=${OVN_REPO:-https://github.com/ovn-org/ovn.git}
 OVN_REPO_NAME=$(basename ${OVN_REPO} | cut -f1 -d'.')
@@ -74,6 +69,9 @@
 # unless the distro kernel includes ovs+conntrack support.
 OVN_BUILD_MODULES=$(trueorfalse False OVN_BUILD_MODULES)
 OVN_BUILD_FROM_SOURCE=$(trueorfalse False OVN_BUILD_FROM_SOURCE)
+if [[ "$OVN_BUILD_FROM_SOURCE" == "True" ]]; then
+    Q_BUILD_OVS_FROM_GIT=True
+fi
 
 # Whether or not to install the ovs python module from ovs source.  This can be
 # used to test and validate new ovs python features.  This should only be used
@@ -341,11 +339,6 @@
 
 # install_ovn() - Collect source and prepare
 function install_ovn {
-    if [[ "$Q_BUILD_OVS_FROM_GIT" == "False" ]]; then
-        echo "Installation of OVS from source disabled."
-        return 0
-    fi
-
     echo "Installing OVN and dependent packages"
 
     # Check the OVN configuration
diff --git a/lib/neutron_plugins/ovs_base b/lib/neutron_plugins/ovs_base
index 2e63fe3..8acf586 100644
--- a/lib/neutron_plugins/ovs_base
+++ b/lib/neutron_plugins/ovs_base
@@ -7,6 +7,12 @@
 _XTRACE_NEUTRON_OVS_BASE=$(set +o | grep xtrace)
 set +o xtrace
 
+# Load devstack ovs compliation and loading functions
+source ${TOP_DIR}/lib/neutron_plugins/ovs_source
+
+# Defaults
+# --------
+
 OVS_BRIDGE=${OVS_BRIDGE:-br-int}
 # OVS recognize default 'system' datapath or 'netdev' for userspace datapath
 OVS_DATAPATH_TYPE=${OVS_DATAPATH_TYPE:-system}
@@ -60,26 +66,33 @@
 }
 
 function _neutron_ovs_base_install_agent_packages {
-    # Install deps
-    install_package $(get_packages "openvswitch")
-    if is_ubuntu; then
-        _neutron_ovs_base_install_ubuntu_dkms
-        restart_service openvswitch-switch
-    elif is_fedora; then
-        restart_service openvswitch
-        sudo systemctl enable openvswitch
-    elif is_suse; then
-        if [[ $DISTRO == "sle12" ]] && vercmp "$os_RELEASE" "<" "12.2" ; then
+    if [ "$Q_BUILD_OVS_FROM_GIT" == "True" ]; then
+        remove_ovs_packages
+        compile_ovs False /usr /var
+        load_conntrack_gre_module
+        start_new_ovs
+    else
+        # Install deps
+        install_package $(get_packages "openvswitch")
+        if is_ubuntu; then
+            _neutron_ovs_base_install_ubuntu_dkms
             restart_service openvswitch-switch
-        else
-            # workaround for https://bugzilla.suse.com/show_bug.cgi?id=1085971
-            if [[ $DISTRO =~ "tumbleweed" ]]; then
-                sudo sed -i -e "s,^OVS_USER_ID=.*,OVS_USER_ID='root:root'," /etc/sysconfig/openvswitch
+        elif is_fedora; then
+            restart_service openvswitch
+            sudo systemctl enable openvswitch
+        elif is_suse; then
+            if [[ $DISTRO == "sle12" ]] && vercmp "$os_RELEASE" "<" "12.2" ; then
+                restart_service openvswitch-switch
+            else
+                # workaround for https://bugzilla.suse.com/show_bug.cgi?id=1085971
+                if [[ $DISTRO =~ "tumbleweed" ]]; then
+                    sudo sed -i -e "s,^OVS_USER_ID=.*,OVS_USER_ID='root:root'," /etc/sysconfig/openvswitch
+                fi
+                restart_service openvswitch || {
+                    journalctl -xe || :
+                    systemctl status openvswitch
+                }
             fi
-            restart_service openvswitch || {
-                journalctl -xe || :
-                systemctl status openvswitch
-            }
         fi
     fi
 }
diff --git a/lib/neutron_plugins/ovs_source b/lib/neutron_plugins/ovs_source
index 08951d1..9c87dce 100644
--- a/lib/neutron_plugins/ovs_source
+++ b/lib/neutron_plugins/ovs_source
@@ -14,6 +14,7 @@
 
 # Defaults
 # --------
+Q_BUILD_OVS_FROM_GIT=$(trueorfalse False Q_BUILD_OVS_FROM_GIT)
 
 # Set variables for building OVS from source
 OVS_REPO=${OVS_REPO:-https://github.com/openvswitch/ovs.git}