Add ZeroMQ RPC backend

Now prevents more than one RPC backend selection.
(ZeroMQ, Qpid, and Rabbit are mutually exclusive)

Configure quantum and cinder to use ZeroMQ

Adds qpid to cinder config.

Change-Id: I229c4c632213a303d097d4a029e986598073665a

README.md

@@ -57,6 +57,22 @@ If the EC2 API is your cup-o-tea, you can create credentials and use euca2ools:
 
 You can override environment variables used in `stack.sh` by creating file name `localrc`.  It is likely that you will need to do this to tweak your networking configuration should you need to access your cloud from a different host.
 
+# RPC Backend
+
+Multiple RPC backends are available. Currently, this
+includes RabbitMQ (default), Qpid, and ZeroMQ. Your backend of
+choice may be selected via the `localrc`.
+
+Note that selecting more than one RPC backend will result in a failure.
+
+Example (ZeroMQ):
+
+    ENABLED_SERVICES="$ENABLED_SERVICES,-rabbit,-qpid,zeromq"
+
+Example (Qpid):
+
+    ENABLED_SERVICES="$ENABLED_SERVICES,-rabbit,-zeromq,qpid"
+
 # Swift
 
 Swift is not installed by default, you can enable easily by adding this to your `localrc`:

lib/cinder

@@ -115,6 +115,8 @@ function configure_cinder() {
 
     if is_service_enabled qpid ; then
         iniset $CINDER_CONF DEFAULT rpc_backend cinder.openstack.common.rpc.impl_qpid
+    elif is_service_enabled zeromq; then
+        iniset $CINDER_CONF DEFAULT rpc_backend nova.openstack.common.rpc.impl_zmq
     elif [ -n "$RABBIT_HOST" ] &&  [ -n "$RABBIT_PASSWORD" ]; then
         iniset $CINDER_CONF DEFAULT rabbit_host $RABBIT_HOST
         iniset $CINDER_CONF DEFAULT rabbit_password $RABBIT_PASSWORD

stack.sh

@@ -142,6 +142,23 @@ if type -p screen >/dev/null && screen -ls | egrep -q "[0-9].stack"; then
     exit 1
 fi
 
+# Make sure we only have one rpc backend enabled.
+rpc_backend_cnt=0
+for svc in qpid zeromq rabbit; do
+    is_service_enabled $svc &&
+        ((rpc_backend_cnt++))
+done
+if [ "$rpc_backend_cnt" -gt 1 ]; then
+    echo "ERROR: only one rpc backend may be enabled,"
+    echo "       set only one of 'rabbit', 'qpid', 'zeromq'"
+    echo "       via ENABLED_SERVICES."
+elif [ "$rpc_backend_cnt" == 0 ]; then
+    echo "ERROR: at least one rpc backend must be enabled,"
+    echo "       set one of 'rabbit', 'qpid', 'zeromq'"
+    echo "       via ENABLED_SERVICES."
+fi
+unset rpc_backend_cnt
+
 # Make sure we only have one volume service enabled.
 if is_service_enabled cinder && is_service_enabled n-vol; then
     echo "ERROR: n-vol and cinder must not be enabled at the same time"
@@ -655,6 +672,12 @@ elif is_service_enabled qpid; then
     else
         install_package qpidd
     fi
+elif is_service_enabled zeromq; then
+    if [[ "$os_PACKAGE" = "rpm" ]]; then
+        install_package zeromq python-zmq
+    else
+        install_package libzmq1 python-zmq
+    fi
 fi
 
 if is_service_enabled mysql; then
@@ -893,8 +916,8 @@ EOF
 fi
 
 
-# Rabbit or Qpid
-# --------------
+# Finalize queue instllation
+# --------------------------
 
 if is_service_enabled rabbit; then
     # Start rabbitmq-server
@@ -1274,6 +1297,8 @@ if is_service_enabled quantum; then
     iniset $Q_CONF_FILE DEFAULT control_exchange quantum
     if is_service_enabled qpid ; then
         iniset $Q_CONF_FILE DEFAULT rpc_backend quantum.openstack.common.rpc.impl_qpid
+    elif is_service_enabled zeromq; then
+        iniset $Q_CONF_FILE DEFAULT rpc_backend quantum.openstack.common.rpc.impl_zmq
     elif [ -n "$RABBIT_HOST" ] &&  [ -n "$RABBIT_PASSWORD" ]; then
         iniset $Q_CONF_FILE DEFAULT rabbit_host $RABBIT_HOST
         iniset $Q_CONF_FILE DEFAULT rabbit_password $RABBIT_PASSWORD
@@ -1898,7 +1923,9 @@ add_nova_opt "vncserver_proxyclient_address=$VNCSERVER_PROXYCLIENT_ADDRESS"
 add_nova_opt "api_paste_config=$NOVA_CONF_DIR/api-paste.ini"
 add_nova_opt "image_service=nova.image.glance.GlanceImageService"
 add_nova_opt "ec2_dmz_host=$EC2_DMZ_HOST"
-if is_service_enabled qpid ; then
+if is_service_enabled zeromq; then
+    add_nova_opt "rpc_backend=nova.openstack.common.rpc.impl_zmq"
+elif is_service_enabled qpid; then
     add_nova_opt "rpc_backend=nova.rpc.impl_qpid"
 elif [ -n "$RABBIT_HOST" ] &&  [ -n "$RABBIT_PASSWORD" ]; then
     add_nova_opt "rabbit_host=$RABBIT_HOST"
@@ -2142,6 +2169,8 @@ if is_service_enabled key; then
     fi
 fi
 
+screen_it zeromq "cd $NOVA_DIR && $NOVA_DIR/bin/nova-rpc-zmq-receiver"
+
 # Launch the nova-api and wait for it to answer before continuing
 if is_service_enabled n-api; then
     add_nova_opt "enabled_apis=$NOVA_ENABLED_APIS"