Compile OVS for functional tests

The patch takes OVS with conntrack support, compiles it and loads its
kernel modules. The patch steals parts from networking-ovn
project [1]. To run compilation of OVS, an environment variable
COMPILE_OVS must be set to True. Optional environment variables
OVS_REPO and OVS_BRANCH can be defined as a source of bits.

Once Neutron starts using neutron-lib, next steps will be taking
content of devstack/lib/ovs and putting it into neutron-lib project
in order to let other projects like networking-ovn to re-use the
code.

[1] https://github.com/openstack/networking-ovn/blob/master/devstack/plugin.sh#L175

Change-Id: Id2f51853a6339da72dbde7a82f94f99a4c306565

TESTING.rst

@@ -127,7 +127,10 @@ Functional tests (neutron/tests/functional/) are intended to
 validate actual system interaction. Mocks should be used sparingly,
 if at all. Care should be taken to ensure that existing system
 resources are not modified and that resources created in tests are
-properly cleaned up both on test success and failure.
+properly cleaned up both on test success and failure. Note that when run
+at the gate, the functional tests compile OVS from source. Check out
+neutron/tests/contrib/gate_hook.sh. Other jobs presently use OVS from
+packages.
 
 Let's examine the benefits of the functional testing framework.
 Neutron offers a library called 'ip_lib' that wraps around the 'ip' binary.

devstack/lib/ovs

@@ -0,0 +1,93 @@
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+OVS_REPO=${OVS_REPO:-https://github.com/openvswitch/ovs.git}
+OVS_REPO_NAME=$(basename ${OVS_REPO} | cut -f1 -d'.')
+OVS_BRANCH=${OVS_BRANCH:-origin/master}
+
+# Functions
+
+# load_module() - Load module using modprobe module given by argument and dies
+#                 on failure
+#               - fatal argument is optional and says whether function should
+#                 exit if module can't be loaded
+function load_module {
+    local module=$1
+    local fatal=$2
+
+    if [ "$(trueorfalse True fatal)" == "True" ]; then
+        sudo modprobe $module || (dmesg && die $LINENO "FAILED TO LOAD $module")
+    else
+        sudo modprobe $module || (echo "FAILED TO LOAD vport_geneve" && dmesg)
+    fi
+}
+
+# compile_ovs() - Compile OVS from source and load needed modules.
+#                 Accepts two parameters:
+#                   - first one is True, modules are built and installed.
+#                   - second optional parameter defines prefix for ovs compilation
+#                 Env variables OVS_REPO_NAME, OVS_REPO and OVS_BRANCH must be set
+function compile_ovs {
+    local _pwd=$PWD
+    local build_modules=${1:-True}
+    local prefix=$2
+
+    if [ -n $prefix ]; then
+        prefix="--prefix=$prefix"
+    fi
+
+    cd $DEST
+    if [ ! -d $OVS_REPO_NAME ] ; then
+        git clone $OVS_REPO
+        cd $OVS_REPO_NAME
+        git checkout $OVS_BRANCH
+    else
+        cd $OVS_REPO_NAME
+    fi
+
+    # TODO: Can you create package list files like you can inside devstack?
+    install_package autoconf automake libtool gcc patch make
+
+    if is_fedora ; then
+        # is_fedora covers Fedora, RHEL, CentOS, etc...
+        install_package kernel-devel
+    fi
+
+    if [ ! -f configure ] ; then
+        ./boot.sh
+    fi
+    if [ ! -f config.status ] || [ configure -nt config.status ] ; then
+        if [[ "$build_modules" == "True" ]]; then
+            ./configure $prefix --with-linux=/lib/modules/$(uname -r)/build
+        else
+            ./configure $prefix
+        fi
+    fi
+    make -j$[$(nproc) + 1]
+    sudo make install
+    if [[ "$build_modules" == "True" ]]; then
+        sudo make INSTALL_MOD_DIR=kernel/net/openvswitch modules_install
+        sudo modprobe -r vport_geneve
+        sudo modprobe -r openvswitch
+    fi
+    load_module openvswitch
+    load_module vport-geneve False
+    dmesg | tail
+
+    cd $_pwd
+}
+
+# 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 /usr/share/openvswitch/scripts/ovs-ctl start
+}

neutron/tests/contrib/gate_hook.sh

@@ -16,12 +16,28 @@ then
     PROJECT_NAME=neutron
     IS_GATE=True
 
+    source $DEVSTACK_PATH/functions
+    source $NEUTRON_PATH/devstack/lib/ovs
+
     source $NEUTRON_PATH/tools/configure_for_func_testing.sh
 
+    configure_host_for_func_testing
+
+    if [[ "$VENV" =~ "dsvm-functional" ]]; then
+        # Build from current branch-2.5 commit (2016-01-15)
+        OVS_BRANCH=eedd0ef239301f68964313e93dfd7ec41fc7814c
+        for package in openvswitch openvswitch-switch openvswitch-common; do
+            if is_package_installed $package; then
+                uninstall_package $package
+            fi
+        done
+        compile_ovs True /usr
+        start_new_ovs
+    fi
+
     # Make the workspace owned by the stack user
     sudo chown -R $STACK_USER:$STACK_USER $BASE
 
-    configure_host_for_func_testing
 elif [ "$VENV" == "api" -o "$VENV" == "api-pecan" -o "$VENV" == "full-pecan" ]
 then
     cat > $DEVSTACK_PATH/local.conf <<EOF