Configure IP tables in devstack plugin

Currently, we instruct users to manually configure IP tables for IP
masquerading. We should take a step forward to automatically configure
IP tables in Magnum's devstack plugin.

Note: The functional gate test needs this patch to allow internet access
inside the provisioned bay.

Change-Id: Ia2ca494f85bfed76a80027bc3310494494d704cd
Closes-Bug: #1478106

devstack/lib/magnum

@@ -17,6 +17,7 @@
 # - init_magnum
 # - magnum_register_image
 # - start_magnum
+# - configure_iptables
 # - stop_magnum
 # - cleanup_magnum
 
@@ -61,6 +62,10 @@ else
     MAGNUM_BIN_DIR=$(get_python_exec_prefix)
 fi
 
+if is_service_enabled ir-api; then
+    MAGNUM_CONFIGURE_IPTABLES=${MAGNUM_CONFIGURE_IPTABLES:-False}
+fi
+
 # Functions
 # ---------
 
@@ -255,6 +260,16 @@ function start_magnum_api {
 }
 
 
+# configure_iptables() - Configure the IP table rules for Magnum
+function configure_iptables {
+    if [ "$MAGNUM_CONFIGURE_IPTABLES" != "False" ]; then
+        ROUTE_TO_INTERNET=$(ip route get 8.8.8.8)
+        OBOUND_DEV=$(echo ${ROUTE_TO_INTERNET#*dev} | awk '{print $1}')
+        sudo iptables -t nat -A POSTROUTING -o $OBOUND_DEV -j MASQUERADE
+    fi
+}
+
+
 # start_magnum() - Start running processes, including screen
 function start_magnum {
 

devstack/plugin.sh

@@ -45,6 +45,8 @@ if is_service_enabled m-api m-cond; then
         # Start the magnum API and magnum taskmgr components
         echo_summary "Starting magnum"
         start_magnum
+
+        configure_iptables
     fi
 
     if [[ "$1" == "unstack" ]]; then

doc/source/dev/dev-quickstart.rst

@@ -141,18 +141,6 @@ http://docs.openstack.org/developer/devstack/configuration.html
 More neutron configuration information can be found at
 http://docs.openstack.org/developer/devstack/guides/neutron.html
 
-Create a local.sh to automatically make necessary networking changes during
-the devstack deployment process. This will allow bays spawned by magnum to
-access the internet through PUBLIC_INTERFACE::
-
-    cat > /opt/stack/devstack/local.sh << 'END_LOCAL_SH'
-    #!/bin/sh
-    ROUTE_TO_INTERNET=$(ip route get 8.8.8.8)
-    OBOUND_DEV=$(echo ${ROUTE_TO_INTERNET#*dev} | awk '{print $1}')
-    sudo iptables -t nat -A POSTROUTING -o $OBOUND_DEV -j MASQUERADE
-    END_LOCAL_SH
-    chmod 755 /opt/stack/devstack/local.sh
-
 Run devstack::
 
     cd /opt/stack/devstack