Quantum/plugins/ryu: minor update for Quantum Ryu plugin

- updated package list for Ryu
  ryu plugin/agent needs python-netifaces
- quantum-ryu-agent also needs ryu module

Change-Id: I5b49efceb65e8139a49a8e82f55ea6aa7d1eebac
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>

files/apts/ryu

@@ -1,4 +1,5 @@
 python-setuptools
 python-gevent
 python-gflags
+python-netifaces
 python-sphinx

files/rpms/ryu

@@ -1,4 +1,5 @@
 python-setuptools
 python-gevent
 python-gflags
+python-netifaces
 python-sphinx

lib/quantum_plugins/ryu

@@ -15,6 +15,9 @@ function quantum_plugin_create_nova_conf() {
 
 function quantum_plugin_install_agent_packages() {
     _quantum_ovs_base_install_agent_packages
+
+    # quantum_ryu_agent requires ryu module
+    install_ryu
 }
 
 function quantum_plugin_configure_common() {

lib/quantum_thirdparty/ryu

@@ -49,8 +49,16 @@ function init_ryu() {
     echo "${RYU_CONF_CONTENTS}" > $RYU_CONF
 }
 
+# install_ryu can be called multiple times as quantum_pluing/ryu may call
+# this function for quantum-ryu-agent
+# Make this function idempotent and avoid cloning same repo many times
+# with RECLONE=yes
+_RYU_INSTALLED=${_RYU_INSTALLED:-False}
 function install_ryu() {
+    if [[ "$_RYU_INSTALLED" == "False" ]]; then
         git_clone $RYU_REPO $RYU_DIR $RYU_BRANCH
+        _RYU_INSTALLED=True
+    fi
 }
 
 function start_ryu() {