Allow for user specified local.conf changes with Vagrant

This adds the ability for the user to inject additional configuration
into local.conf during the provisioning step. One can change the
Neutron plugin, for example, using this configuration.

Change-Id: If778960edb1d9c3a23c7947c5ba3bf8a07bdfc3a
Signed-off-by: Kyle Mestery <mestery@mestery.com>

.gitignore

@@ -55,3 +55,6 @@ contrib/vagrant/.vagrant
 # Configuration files
 etc/kuryr.conf
 etc/kuryr.conf.sample
+
+# Ignore user specific local.conf settings for vagrant
+contrib/vagrant/user_local.conf

contrib/vagrant/README.md

@@ -47,4 +47,21 @@ the definition of the Virtual Machine spawned:
  * **VAGRANT\_KURYR\_VM\_CPU**: To modify the cpus of the VM. Defaulted to: 2
  * **VAGRANT\_KURYR\_RUN\_DEVSTACK**: Whether `vagrant up` should run devstack to
    have an environment ready to use. Set it to 'false' if you want to edit
-   `local.conf` before run ./stack.sh manually in the VM. Defaulted to: true
+   `local.conf` before run ./stack.sh manually in the VM. Defaulted to: true.
+   See below for additional options for editing local.conf.
+
+Additional devstack configuration
+---------------------------------
+
+To add additional configuration to local.conf before the VM is provisioned, you can
+create a file called "user_local.conf" in the contrib/vagrant directory of
+networking-kuryr. This file will be appended to the "local.conf" created during the
+Vagrant provisioning.
+
+For example, to use OVN as the Neutron plugin with Kuryr, you can create a
+"user_local.conf" with the following configuration:
+
+    enable_plugin networking-ovn http://git.openstack.org/openstack/networking-ovn
+    enable_service ovn-northd
+    enable_service ovn-controller
+    disable_service q-agt

contrib/vagrant/devstack.sh

@@ -44,6 +44,10 @@ then
 
   # copy local.conf.sample settings (source: kuryr/devstack/local.conf.sample)
   cp /devstack/local.conf.sample $DEVSTACK/local.conf
+  # If local settings are present, append them
+  if [ -f "/vagrant/user_local.conf" ]; then
+    cat /vagrant/user_local.conf >> $DEVSTACK/local.conf
+  fi
   chown "$OS_USER":"$OS_USER" "$DEVSTACK"/local.conf
 
 fi