Add an option to enable version 1.0 of the AMQP messaging protocol

This change adds the RPC_MESSAGING_PROTOCOL configuration option that
selects the messaging protocol that is used by the RPC backend and
client.

Some brokers can support different kinds of 'on the wire' messaging
protocols.  Qpid, for example, supports both AMQP 0-10 (the default),
and AMQP 1.0.  Use the RPC_MESSAGING_PROTOCOL configuration variable
to override the default protocol for those brokers that support
multiple protocol options.

This new option is necessary in order to enable the new AMQP 1.0
oslo.messaging transport as described in the blueprint.

Note well: currently this AMQP 1.0 functionality is only available on
fedora 19+ platforms.  Support is WIP on ubuntu/debian and rhel/centos
7. Enabling the RPC_MESSAGING_PROTOCOL option on an unsupported
platform will cause devstack to exit with an approriate error
message.

Change-Id: Ib8dea59922844e87d6c947b5dca557f5b5fc1160
Implements: blueprint amqp10-driver-implementation
diff --git a/lib/rpc_backend b/lib/rpc_backend
index 38da50c..8342aef 100644
--- a/lib/rpc_backend
+++ b/lib/rpc_backend
@@ -6,6 +6,7 @@
 #
 # - ``functions`` file
 # - ``RABBIT_{HOST|PASSWORD}`` must be defined when RabbitMQ is used
+# - ``RPC_MESSAGING_PROTOCOL`` option for configuring the messaging protocol
 
 # ``stack.sh`` calls the entry points in this order:
 #
@@ -90,21 +91,56 @@
             exit_distro_not_supported "zeromq installation"
         fi
     fi
+
+    # Remove the AMQP 1.0 messaging libraries
+    if [ "$RPC_MESSAGING_PROTOCOL" == "AMQP1" ]; then
+        if is_fedora; then
+            uninstall_package qpid-proton-c-devel
+            uninstall_package python-qpid-proton
+        fi
+        # TODO(kgiusti) ubuntu cleanup
+    fi
 }
 
 # install rpc backend
 function install_rpc_backend {
+    # Regardless of the broker used, if AMQP 1.0 is configured load
+    # the necessary messaging client libraries for oslo.messaging
+    if [ "$RPC_MESSAGING_PROTOCOL" == "AMQP1" ]; then
+        if is_fedora; then
+            install_package qpid-proton-c-devel
+            install_package python-qpid-proton
+        elif is_ubuntu; then
+            # TODO(kgiusti) The QPID AMQP 1.0 protocol libraries
+            # are not yet in the ubuntu repos. Enable these installs
+            # once they are present:
+            #install_package libqpid-proton2-dev
+            #install_package python-qpid-proton
+            # Also add 'uninstall' directives in cleanup_rpc_backend()!
+            exit_distro_not_supported "QPID AMQP 1.0 Proton libraries"
+        else
+            exit_distro_not_supported "QPID AMQP 1.0 Proton libraries"
+        fi
+        # Install pyngus client API
+        # TODO(kgiusti) can remove once python qpid bindings are
+        # available on all supported platforms _and_ pyngus is added
+        # to the requirements.txt file in oslo.messaging
+        pip_install pyngus
+    fi
+
     if is_service_enabled rabbit; then
         # Install rabbitmq-server
         install_package rabbitmq-server
     elif is_service_enabled qpid; then
+        local qpid_conf_file=/etc/qpid/qpidd.conf
         if is_fedora; then
             install_package qpid-cpp-server
             if [[ $DISTRO =~ (rhel6) ]]; then
+                qpid_conf_file=/etc/qpidd.conf
                 # RHEL6 leaves "auth=yes" in /etc/qpidd.conf, it needs to
                 # be no or you get GSS authentication errors as it
                 # attempts to default to this.
-                sudo sed -i.bak 's/^auth=yes$/auth=no/' /etc/qpidd.conf
+                sudo sed -i.bak 's/^auth=yes$/auth=no/' $qpid_conf_file
             fi
         elif is_ubuntu; then
             install_package qpidd
@@ -113,6 +149,22 @@
         else
             exit_distro_not_supported "qpid installation"
         fi
+        # If AMQP 1.0 is specified, ensure that the version of the
+        # broker can support AMQP 1.0 and configure the queue and
+        # topic address patterns used by oslo.messaging.
+        if [ "$RPC_MESSAGING_PROTOCOL" == "AMQP1" ]; then
+            QPIDD=$(type -p qpidd)
+            if ! $QPIDD --help | grep -q "queue-patterns"; then
+                exit_distro_not_supported "qpidd with AMQP 1.0 support"
+            fi
+            if ! grep -q "queue-patterns=exclusive" $qpid_conf_file; then
+                cat <<EOF | sudo tee --append $qpid_conf_file
+queue-patterns=exclusive
+queue-patterns=unicast
+topic-patterns=broadcast
+EOF
+            fi
+        fi
     elif is_service_enabled zeromq; then
         # NOTE(ewindisch): Redis is not strictly necessary
         # but there is a matchmaker driver that works
@@ -176,7 +228,12 @@
         MATCHMAKER_REDIS_HOST=${MATCHMAKER_REDIS_HOST:-127.0.0.1}
         iniset $file matchmaker_redis host $MATCHMAKER_REDIS_HOST
     elif is_service_enabled qpid || [ -n "$QPID_HOST" ]; then
-        iniset $file $section rpc_backend ${package}.openstack.common.rpc.impl_qpid
+        # For Qpid use the 'amqp' oslo.messaging transport when AMQP 1.0 is used
+        if [ "$RPC_MESSAGING_PROTOCOL" == "AMQP1" ]; then
+            iniset $file $section rpc_backend "amqp"
+        else
+            iniset $file $section rpc_backend ${package}.openstack.common.rpc.impl_qpid
+        fi
         iniset $file $section qpid_hostname ${QPID_HOST:-$SERVICE_HOST}
         if is_ubuntu; then
             QPID_PASSWORD=`sudo strings /etc/qpid/qpidd.sasldb | grep -B1 admin | head -1`