From 2aa2a89cdb9071cea919116e283c16ac9dd841d6 Mon Sep 17 00:00:00 2001
From: Dean Troyer <dtroyer@gmail.com>
Date: Sun, 4 Aug 2013 19:53:19 -0500
Subject: [PATCH] Add support for Docker as Nova hypervisor

* Add basic support for hypervisor plugins in lib/nova_plugins
* Add lib/nova_plugins/hypervisor-docker to use Docker as a Nova
  hypervisor.
* Add tools/install_docker.sh to install the Docker daemon and
  registry container, download base image and import
* Configure Nova to use docker plugin
* Add docker exercise and skip unsupported ones

Nova blueprint: new-hypervisor-docker

Change-Id: I9e7065b562dce2ce853def583ab1165886612227
---
 README.md                          |   6 +-
 clean.sh                           |   5 ++
 exercises/boot_from_volume.sh      |   3 +
 exercises/docker.sh                | 105 +++++++++++++++++++++++
 exercises/euca.sh                  |   3 +
 exercises/floating_ips.sh          |   3 +
 exercises/sec_groups.sh            |   3 +
 exercises/volumes.sh               |   3 +
 lib/nova                           |  17 +++-
 lib/nova_plugins/hypervisor-docker | 132 +++++++++++++++++++++++++++++
 stack.sh                           |  18 +++-
 tools/docker/README.md             |  13 +++
 tools/docker/install_docker.sh     |  75 ++++++++++++++++
 unstack.sh                         |   8 ++
 14 files changed, 391 insertions(+), 3 deletions(-)
 create mode 100755 exercises/docker.sh
 create mode 100644 lib/nova_plugins/hypervisor-docker
 create mode 100644 tools/docker/README.md
 create mode 100755 tools/docker/install_docker.sh

diff --git a/README.md b/README.md
index 6426e9a4ed..99e983887e 100644
--- a/README.md
+++ b/README.md
@@ -12,10 +12,14 @@ Read more at http://devstack.org (built from the gh-pages branch)
 
 IMPORTANT: Be sure to carefully read `stack.sh` and any other scripts you execute before you run them, as they install software and may alter your networking configuration.  We strongly recommend that you run `stack.sh` in a clean and disposable vm when you are first getting started.
 
-# Devstack on Xenserver
+# DevStack on Xenserver
 
 If you would like to use Xenserver as the hypervisor, please refer to the instructions in `./tools/xen/README.md`.
 
+# DevStack on Docker
+
+If you would like to use Docker as the hypervisor, please refer to the instructions in `./tools/docker/README.md`.
+
 # Versions
 
 The devstack master branch generally points to trunk versions of OpenStack components.  For older, stable versions, look for branches named stable/[release] in the DevStack repo.  For example, you can do the following to create a diablo OpenStack cloud:
diff --git a/clean.sh b/clean.sh
index f7d15dfe4e..a443ac82d0 100755
--- a/clean.sh
+++ b/clean.sh
@@ -64,6 +64,11 @@ cleanup_nova
 cleanup_neutron
 cleanup_swift
 
+# Do the hypervisor cleanup until this can be moved back into lib/nova
+if [[ -r $NOVA_PLUGINS/hypervisor-$VIRT_DRIVER ]]; then
+    cleanup_nova_hypervisor
+fi
+
 # cinder doesn't always clean up the volume group as it might be used elsewhere...
 # clean it up if it is a loop device
 VG_DEV=$(sudo losetup -j $DATA_DIR/${VOLUME_GROUP}-backing-file | awk -F':' '/backing-file/ { print $1}')
diff --git a/exercises/boot_from_volume.sh b/exercises/boot_from_volume.sh
index 36524ede4b..fe27bd0956 100755
--- a/exercises/boot_from_volume.sh
+++ b/exercises/boot_from_volume.sh
@@ -44,6 +44,9 @@ source $TOP_DIR/exerciserc
 # the exercise is skipped
 is_service_enabled cinder || exit 55
 
+# Also skip if the hypervisor is Docker
+[[ "$VIRT_DRIVER" == "docker" ]] && exit 55
+
 # Instance type to create
 DEFAULT_INSTANCE_TYPE=${DEFAULT_INSTANCE_TYPE:-m1.tiny}
 
diff --git a/exercises/docker.sh b/exercises/docker.sh
new file mode 100755
index 0000000000..0672bc0087
--- /dev/null
+++ b/exercises/docker.sh
@@ -0,0 +1,105 @@
+#!/usr/bin/env bash
+
+# **docker**
+
+# Test Docker hypervisor
+
+echo "*********************************************************************"
+echo "Begin DevStack Exercise: $0"
+echo "*********************************************************************"
+
+# This script exits on an error so that errors don't compound and you see
+# only the first error that occurred.
+set -o errexit
+
+# Print the commands being run so that we can see the command that triggers
+# an error.  It is also useful for following allowing as the install occurs.
+set -o xtrace
+
+
+# Settings
+# ========
+
+# Keep track of the current directory
+EXERCISE_DIR=$(cd $(dirname "$0") && pwd)
+TOP_DIR=$(cd $EXERCISE_DIR/..; pwd)
+
+# Import common functions
+source $TOP_DIR/functions
+
+# Import configuration
+source $TOP_DIR/openrc
+
+# Import exercise configuration
+source $TOP_DIR/exerciserc
+
+# Skip if the hypervisor is not Docker
+[[ "$VIRT_DRIVER" == "docker" ]] || exit 55
+
+# Import docker functions and declarations
+source $TOP_DIR/lib/nova_plugins/hypervisor-docker
+
+# Image and flavor are ignored but the CLI requires them...
+
+# Instance type to create
+DEFAULT_INSTANCE_TYPE=${DEFAULT_INSTANCE_TYPE:-m1.tiny}
+
+# Boot this image, use first AMI image if unset
+DEFAULT_IMAGE_NAME=${DEFAULT_IMAGE_NAME:-ami}
+
+# Instance name
+VM_NAME=ex-docker
+
+
+# Launching a server
+# ==================
+
+# Grab the id of the image to launch
+IMAGE=$(glance image-list | egrep " $DOCKER_IMAGE_NAME:latest " | get_field 1)
+die_if_not_set $LINENO IMAGE "Failure getting image $DOCKER_IMAGE_NAME"
+
+# Select a flavor
+INSTANCE_TYPE=$(nova flavor-list | grep $DEFAULT_INSTANCE_TYPE | get_field 1)
+if [[ -z "$INSTANCE_TYPE" ]]; then
+    # grab the first flavor in the list to launch if default doesn't exist
+   INSTANCE_TYPE=$(nova flavor-list | head -n 4 | tail -n 1 | get_field 1)
+fi
+
+# Clean-up from previous runs
+nova delete $VM_NAME || true
+if ! timeout $ACTIVE_TIMEOUT sh -c "while nova show $VM_NAME; do sleep 1; done"; then
+    die $LINENO "server didn't terminate!"
+fi
+
+# Boot instance
+# -------------
+
+VM_UUID=$(nova boot --flavor $INSTANCE_TYPE --image $IMAGE $VM_NAME | grep ' id ' | get_field 2)
+die_if_not_set $LINENO VM_UUID "Failure launching $VM_NAME"
+
+# Check that the status is active within ACTIVE_TIMEOUT seconds
+if ! timeout $ACTIVE_TIMEOUT sh -c "while ! nova show $VM_UUID | grep status | grep -q ACTIVE; do sleep 1; done"; then
+    die $LINENO "server didn't become active!"
+fi
+
+# Get the instance IP
+IP=$(nova show $VM_UUID | grep "$PRIVATE_NETWORK_NAME" | get_field 2)
+die_if_not_set $LINENO IP "Failure retrieving IP address"
+
+# Private IPs can be pinged in single node deployments
+ping_check "$PRIVATE_NETWORK_NAME" $IP $BOOT_TIMEOUT
+
+# Clean up
+# --------
+
+# Delete instance
+nova delete $VM_UUID || die $LINENO "Failure deleting instance $VM_NAME"
+if ! timeout $TERMINATE_TIMEOUT sh -c "while nova list | grep -q $VM_UUID; do sleep 1; done"; then
+    die $LINENO "Server $VM_NAME not deleted"
+fi
+
+set +o xtrace
+echo "*********************************************************************"
+echo "SUCCESS: End DevStack Exercise: $0"
+echo "*********************************************************************"
+
diff --git a/exercises/euca.sh b/exercises/euca.sh
index b8b283a8fb..64c0014236 100755
--- a/exercises/euca.sh
+++ b/exercises/euca.sh
@@ -41,6 +41,9 @@ fi
 # Import exercise configuration
 source $TOP_DIR/exerciserc
 
+# Skip if the hypervisor is Docker
+[[ "$VIRT_DRIVER" == "docker" ]] && exit 55
+
 # Instance type to create
 DEFAULT_INSTANCE_TYPE=${DEFAULT_INSTANCE_TYPE:-m1.tiny}
 
diff --git a/exercises/floating_ips.sh b/exercises/floating_ips.sh
index f93a727df6..2833b650ba 100755
--- a/exercises/floating_ips.sh
+++ b/exercises/floating_ips.sh
@@ -38,6 +38,9 @@ fi
 # Import exercise configuration
 source $TOP_DIR/exerciserc
 
+# Skip if the hypervisor is Docker
+[[ "$VIRT_DRIVER" == "docker" ]] && exit 55
+
 # Instance type to create
 DEFAULT_INSTANCE_TYPE=${DEFAULT_INSTANCE_TYPE:-m1.tiny}
 
diff --git a/exercises/sec_groups.sh b/exercises/sec_groups.sh
index 6b67291cde..7d80570326 100755
--- a/exercises/sec_groups.sh
+++ b/exercises/sec_groups.sh
@@ -33,6 +33,9 @@ source $TOP_DIR/openrc
 # Import exercise configuration
 source $TOP_DIR/exerciserc
 
+# Skip if the hypervisor is Docker
+[[ "$VIRT_DRIVER" == "docker" ]] && exit 55
+
 
 # Testing Security Groups
 # =======================
diff --git a/exercises/volumes.sh b/exercises/volumes.sh
index 028d19b36a..e536d16249 100755
--- a/exercises/volumes.sh
+++ b/exercises/volumes.sh
@@ -42,6 +42,9 @@ source $TOP_DIR/exerciserc
 # exercise is skipped.
 is_service_enabled cinder || exit 55
 
+# Also skip if the hypervisor is Docker
+[[ "$VIRT_DRIVER" == "docker" ]] && exit 55
+
 # Instance type to create
 DEFAULT_INSTANCE_TYPE=${DEFAULT_INSTANCE_TYPE:-m1.tiny}
 
diff --git a/lib/nova b/lib/nova
index 842c098624..3486aa8fb9 100644
--- a/lib/nova
+++ b/lib/nova
@@ -169,6 +169,13 @@ function cleanup_nova() {
     fi
 
     sudo rm -rf $NOVA_STATE_PATH $NOVA_AUTH_CACHE_DIR
+
+    # NOTE(dtroyer): This really should be called from here but due to the way
+    #                nova abuses the _cleanup() function we're moving it
+    #                directly into cleanup.sh until this can be fixed.
+    #if is_service_enabled n-cpu && [[ -r $NOVA_PLUGINS/hypervisor-$VIRT_DRIVER ]]; then
+    #    cleanup_nova_hypervisor
+    #fi
 }
 
 # configure_nova_rootwrap() - configure Nova's rootwrap
@@ -650,7 +657,9 @@ function install_novaclient() {
 # install_nova() - Collect source and prepare
 function install_nova() {
     if is_service_enabled n-cpu; then
-        if [[ "$VIRT_DRIVER" = 'libvirt' ]]; then
+        if [[ -r $NOVA_PLUGINS/hypervisor-$VIRT_DRIVER ]]; then
+            install_nova_hypervisor
+        elif [[ "$VIRT_DRIVER" = 'libvirt' ]]; then
             if is_ubuntu; then
                 install_package kvm
                 install_package libvirt-bin
@@ -728,6 +737,9 @@ function start_nova() {
            screen_it n-cpu "cd $NOVA_DIR && $NOVA_BIN_DIR/nova-compute --config-file $NOVA_CONF_BOTTOM"
        done
     else
+        if is_service_enabled n-cpu && [[ -r $NOVA_PLUGINS/hypervisor-$VIRT_DRIVER ]]; then
+            start_nova_hypervisor
+        fi
         screen_it n-cpu "cd $NOVA_DIR && $NOVA_BIN_DIR/nova-compute --config-file $NOVA_CONF_BOTTOM"
     fi
     screen_it n-crt "cd $NOVA_DIR && $NOVA_BIN_DIR/nova-cert"
@@ -754,6 +766,9 @@ function stop_nova() {
     for serv in n-api n-cpu n-crt n-net n-sch n-novnc n-xvnc n-cauth n-spice n-cond n-cond n-cell n-cell n-api-meta; do
         screen -S $SCREEN_NAME -p $serv -X kill
     done
+    if is_service_enabled n-cpu && [[ -r $NOVA_PLUGINS/hypervisor-$VIRT_DRIVER ]]; then
+        stop_nova_hypervisor
+    fi
 }
 
 
diff --git a/lib/nova_plugins/hypervisor-docker b/lib/nova_plugins/hypervisor-docker
new file mode 100644
index 0000000000..4c8fc279b0
--- /dev/null
+++ b/lib/nova_plugins/hypervisor-docker
@@ -0,0 +1,132 @@
+# lib/nova_plugins/docker
+# Configure the Docker hypervisor
+
+# Enable with:
+# VIRT_DRIVER=docker
+
+# Dependencies:
+# ``functions`` file
+# ``nova`` and ``glance`` configurations
+
+# install_nova_hypervisor - install any external requirements
+# configure_nova_hypervisor - make configuration changes, including those to other services
+# start_nova_hypervisor - start any external services
+# stop_nova_hypervisor - stop any external services
+# cleanup_nova_hypervisor - remove transient data and cache
+
+# Save trace setting
+MY_XTRACE=$(set +o | grep xtrace)
+set +o xtrace
+
+
+# Defaults
+# --------
+
+# Set up default directories
+DOCKER_DIR=$DEST/docker
+DOCKER_REPO=${DOCKER_REPO:-https://github.com/dotcloud/openstack-docker.git}
+DOCKER_BRANCH=${DOCKER_BRANCH:-master}
+
+DOCKER_UNIX_SOCKET=/var/run/docker.sock
+DOCKER_PID_FILE=/var/run/docker.pid
+DOCKER_REGISTRY_PORT=${DOCKER_REGISTRY_PORT:-5042}
+
+DOCKER_IMAGE=${DOCKER_IMAGE:-http://get.docker.io/images/openstack/docker-ut.tar.gz}
+DOCKER_IMAGE_NAME=docker-busybox
+DOCKER_REGISTRY_IMAGE=${DOCKER_REGISTRY_IMAGE:-http://get.docker.io/images/openstack/docker-registry.tar.gz}
+DOCKER_REGISTRY_IMAGE_NAME=docker-registry
+DOCKER_REPOSITORY_NAME=${SERVICE_HOST}:${DOCKER_REGISTRY_PORT}/${DOCKER_IMAGE_NAME}
+
+DOCKER_PACKAGE_VERSION=${DOCKER_PACKAGE_VERSION:-0.6.1}
+DOCKER_APT_REPO=${DOCKER_APT_REPO:-https://get.docker.io/ubuntu}
+
+
+# Entry Points
+# ------------
+
+# clean_nova_hypervisor - Clean up an installation
+function cleanup_nova_hypervisor() {
+    stop_service docker
+
+    # Clean out work area
+    sudo rm -rf /var/lib/docker
+}
+
+# configure_nova_hypervisor - Set config files, create data dirs, etc
+function configure_nova_hypervisor() {
+    git_clone $DOCKER_REPO $DOCKER_DIR $DOCKER_BRANCH
+
+    ln -snf ${DOCKER_DIR}/nova-driver $NOVA_DIR/nova/virt/docker
+
+    iniset $NOVA_CONF DEFAULT compute_driver docker.DockerDriver
+    iniset $GLANCE_API_CONF DEFAULT container_formats ami,ari,aki,bare,ovf,docker
+
+    sudo cp -p ${DOCKER_DIR}/nova-driver/docker.filters $NOVA_CONF_DIR/rootwrap.d
+}
+
+# install_nova_hypervisor() - Install external components
+function install_nova_hypervisor() {
+    # So far this is Ubuntu only
+    if ! is_ubuntu; then
+        die $LINENO "Docker is only supported on Ubuntu at this time"
+    fi
+
+    # Make sure Docker is installed
+    if ! is_package_installed lxc-docker; then
+        die $LINENO "Docker is not installed.  Please run tools/docker/install_docker.sh"
+    fi
+
+    local docker_pid
+    read docker_pid <$DOCKER_PID_FILE
+    if [[ -z $docker_pid ]] || ! ps -p $docker_pid | grep [d]ocker; then
+        die $LINENO "Docker not running"
+    fi
+}
+
+# start_nova_hypervisor - Start any required external services
+function start_nova_hypervisor() {
+    local docker_pid
+    read docker_pid <$DOCKER_PID_FILE
+    if [[ -z $docker_pid ]] || ! ps -p $docker_pid | grep [d]ocker; then
+        die $LINENO "Docker not running, start the daemon"
+    fi
+
+    # Start the Docker registry container
+    docker run -d -p ${DOCKER_REGISTRY_PORT}:5000 \
+        -e SETTINGS_FLAVOR=openstack -e OS_USERNAME=${OS_USERNAME} \
+        -e OS_PASSWORD=${OS_PASSWORD} -e OS_TENANT_NAME=${OS_TENANT_NAME} \
+        -e OS_GLANCE_URL="${SERVICE_PROTOCOL}://${GLANCE_HOSTPORT}" \
+        -e OS_AUTH_URL=${OS_AUTH_URL} \
+        $DOCKER_REGISTRY_IMAGE_NAME ./docker-registry/run.sh
+
+    echo "Waiting for docker registry to start..."
+    DOCKER_REGISTRY=${SERVICE_HOST}:${DOCKER_REGISTRY_PORT}
+    if ! timeout $SERVICE_TIMEOUT sh -c "while ! curl -s $DOCKER_REGISTRY; do sleep 1; done"; then
+        die $LINENO "docker-registry did not start"
+    fi
+
+    # Tag image if not already tagged
+    if ! docker images | grep $DOCKER_REPOSITORY_NAME; then
+        docker tag $DOCKER_IMAGE_NAME $DOCKER_REPOSITORY_NAME
+    fi
+
+    # Make sure we copied the image in Glance
+    DOCKER_IMAGE=$(glance image-list | egrep " $DOCKER_IMAGE_NAME ")
+    if ! is_set DOCKER_IMAGE ; then
+        docker push $DOCKER_REPOSITORY_NAME
+    fi
+}
+
+# stop_nova_hypervisor - Stop any external services
+function stop_nova_hypervisor() {
+    # Stop the docker registry container
+    docker kill $(docker ps | grep docker-registry | cut -d' ' -f1)
+}
+
+
+# Restore xtrace
+$MY_XTRACE
+
+# Local variables:
+# mode: shell-script
+# End:
diff --git a/stack.sh b/stack.sh
index 8f59328792..c3f69adcf1 100755
--- a/stack.sh
+++ b/stack.sh
@@ -319,6 +319,13 @@ source $TOP_DIR/lib/neutron
 source $TOP_DIR/lib/baremetal
 source $TOP_DIR/lib/ldap
 
+# Look for Nova hypervisor plugin
+NOVA_PLUGINS=$TOP_DIR/lib/nova_plugins
+if is_service_enabled nova && [[ -r $NOVA_PLUGINS/hypervisor-$VIRT_DRIVER ]]; then
+    # Load plugin
+    source $NOVA_PLUGINS/hypervisor-$VIRT_DRIVER
+fi
+
 # Set the destination directories for other OpenStack projects
 OPENSTACKCLIENT_DIR=$DEST/python-openstackclient
 
@@ -1013,6 +1020,10 @@ if is_service_enabled cinder; then
     init_cinder
 fi
 
+
+# Compute Service
+# ---------------
+
 if is_service_enabled nova; then
     echo_summary "Configuring Nova"
     # Rebuild the config file from scratch
@@ -1027,10 +1038,15 @@ if is_service_enabled nova; then
     fi
 
 
+    if [[ -r $NOVA_PLUGINS/hypervisor-$VIRT_DRIVER ]]; then
+        # Configure hypervisor plugin
+        configure_nova_hypervisor
+
+
     # XenServer
     # ---------
 
-    if [ "$VIRT_DRIVER" = 'xenserver' ]; then
+    elif [ "$VIRT_DRIVER" = 'xenserver' ]; then
         echo_summary "Using XenServer virtualization driver"
         if [ -z "$XENAPI_CONNECTION_URL" ]; then
             die $LINENO "XENAPI_CONNECTION_URL is not specified"
diff --git a/tools/docker/README.md b/tools/docker/README.md
new file mode 100644
index 0000000000..976111f750
--- /dev/null
+++ b/tools/docker/README.md
@@ -0,0 +1,13 @@
+# DevStack on Docker
+
+Using Docker as Nova's hypervisor requries two steps:
+
+* Configure DevStack by adding the following to `localrc`::
+
+    VIRT_DRIVER=docker
+
+* Download and install the Docker service and images::
+
+    tools/docker/install_docker.sh
+
+After this, `stack.sh` should run as normal.
diff --git a/tools/docker/install_docker.sh b/tools/docker/install_docker.sh
new file mode 100755
index 0000000000..d659ad104b
--- /dev/null
+++ b/tools/docker/install_docker.sh
@@ -0,0 +1,75 @@
+#!/usr/bin/env bash
+
+# **install_docker.sh** - Do the initial Docker installation and configuration
+
+# install_docker.sh
+#
+# Install docker package and images
+# * downloads a base busybox image and a glance registry image if necessary
+# * install the images in Docker's image cache
+
+
+# Keep track of the current directory
+SCRIPT_DIR=$(cd $(dirname "$0") && pwd)
+TOP_DIR=$(cd $SCRIPT_DIR/../..; pwd)
+
+# Import common functions
+source $TOP_DIR/functions
+
+# Load local configuration
+source $TOP_DIR/stackrc
+
+FILES=$TOP_DIR/files
+
+# Get our defaults
+source $TOP_DIR/lib/nova_plugins/hypervisor-docker
+
+SERVICE_TIMEOUT=${SERVICE_TIMEOUT:-60}
+
+
+# Install Docker Service
+# ======================
+
+# Stop the auto-repo updates and do it when required here
+NO_UPDATE_REPOS=True
+
+# Set up home repo
+curl https://get.docker.io/gpg | sudo apt-key add -
+install_package python-software-properties && \
+    sudo sh -c "echo deb $DOCKER_APT_REPO docker main > /etc/apt/sources.list.d/docker.list"
+apt_get update
+install_package --force-yes lxc-docker=${DOCKER_PACKAGE_VERSION}
+
+# Start the daemon - restart just in case the package ever auto-starts...
+restart_service docker
+
+echo "Waiting for docker daemon to start..."
+DOCKER_GROUP=$(groups | cut -d' ' -f1)
+CONFIGURE_CMD="while ! /bin/echo -e 'GET /v1.3/version HTTP/1.0\n\n' | socat - unix-connect:$DOCKER_UNIX_SOCKET | grep -q '200 OK'; do
+    # Set the right group on docker unix socket before retrying
+    sudo chgrp $DOCKER_GROUP $DOCKER_UNIX_SOCKET
+    sudo chmod g+rw $DOCKER_UNIX_SOCKET
+    sleep 1
+done"
+if ! timeout $SERVICE_TIMEOUT sh -c "$CONFIGURE_CMD"; then
+    die $LINENO "docker did not start"
+fi
+
+
+# Get Docker image
+if [[ ! -r $FILES/docker-ut.tar.gz ]]; then
+    (cd $FILES; curl -OR $DOCKER_IMAGE)
+fi
+if [[ ! -r $FILES/docker-ut.tar.gz ]]; then
+    die $LINENO "Docker image unavailable"
+fi
+docker import - $DOCKER_IMAGE_NAME <$FILES/docker-ut.tar.gz
+
+# Get Docker registry image
+if [[ ! -r $FILES/docker-registry.tar.gz ]]; then
+    (cd $FILES; curl -OR $DOCKER_REGISTRY_IMAGE)
+fi
+if [[ ! -r $FILES/docker-registry.tar.gz ]]; then
+    die $LINENO "Docker registry image unavailable"
+fi
+docker import - $DOCKER_REGISTRY_IMAGE_NAME <$FILES/docker-registry.tar.gz
diff --git a/unstack.sh b/unstack.sh
index 2268b90458..f053bcddd8 100755
--- a/unstack.sh
+++ b/unstack.sh
@@ -65,6 +65,14 @@ if [[ -n "$SCREEN" ]]; then
     fi
 fi
 
+# Shut down Nova hypervisor plugins after Nova
+NOVA_PLUGINS=$TOP_DIR/lib/nova_plugins
+if is_service_enabled nova && [[ -r $NOVA_PLUGINS/hypervisor-$VIRT_DRIVER ]]; then
+    # Load plugin
+    source $NOVA_PLUGINS/hypervisor-$VIRT_DRIVER
+    stop_nova_hypervisor
+fi
+
 # Swift runs daemons
 if is_service_enabled s-proxy; then
     stop_swift