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
diff --git a/lib/nova b/lib/nova
index 842c098..3486aa8 100644
--- a/lib/nova
+++ b/lib/nova
@@ -169,6 +169,13 @@
     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 @@
 # 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 @@
            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 @@
     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 0000000..4c8fc27
--- /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: