devstack-plugin-glusterfs: GlusterFS as a backend for glance

This patch enables GlusterFS as a backend for Glance. This
patch introduces two new configuration parameters:
 * CONFIGURE_GLUSTERFS_GLANCE - set to 'True', to enable GlusterFS
as a backend for Glance. By default set to True.
 * GLANCE_GLUSTERFS_SHARE - which specifies the GlusterFS share
to store glance images.

Change-Id: I613e4c7a3e359235f5d54abc820df95b521b8697

devstack/gluster-functions.sh

@@ -91,6 +91,11 @@ function cleanup_glusterfs {
         _delete_gluster_shares $CINDER_GLUSTERFS_SHARES
     fi
 
+    # Cleaning up Glance GlusterFS share
+    if [ "$CONFIGURE_GLUSTERFS_GLANCE" = "True" ]; then
+        _delete_gluster_shares $GLANCE_GLUSTERFS_SHARE
+    fi
+
     if [[ -e ${GLUSTERFS_DISK_IMAGE} ]]; then
         sudo rm -f ${GLUSTERFS_DISK_IMAGE}
     fi
@@ -155,3 +160,23 @@ function configure_cinder_backend_glusterfs {
         echo "$CINDER_GLUSTERFS_SHARES" | tee "$CINDER_CONF_DIR/glusterfs-shares-$be_name.conf"
     fi
 }
+
+# Mount gluster volume
+function _mount_gluster_volume {
+    local mount_dir=$1
+    local gluster_share=$2
+
+    # Delete existing files in directory
+    rm -rf $mount_dir
+    mkdir -p $mount_dir
+
+    sudo mount -t glusterfs $gluster_share $mount_dir
+    sudo chown -R $STACK_USER:$STACK_USER $DATA_DIR
+}
+
+# Configure GlusterFS as a backend for Glance
+function configure_glance_backend_glusterfs {
+    _create_gluster_volumes $GLANCE_GLUSTERFS_SHARE
+
+    _mount_gluster_volume $GLANCE_IMAGE_DIR $GLANCE_GLUSTERFS_SHARE
+}

devstack/plugin.sh

@@ -13,6 +13,7 @@
 # - install_glusterfs
 # - start_glusterfs
 # - configure_cinder_backend_glusterfs
+# - configure_glance_backend_glusterfs
 # - stop_glusterfs
 # - cleanup_glusterfs
 
@@ -22,10 +23,13 @@
 # Set CONFIGURE_GLUSTERFS_CINDER to true, to enable GlusterFS as a backend for Cinder.
 CONFIGURE_GLUSTERFS_CINDER=${CONFIGURE_GLUSTERFS_CINDER:-True}
 
+# Set CONFIGURE_GLUSTERFS_GLANCE to true, to configure GlusterFS as a backend for Glance.
+CONFIGURE_GLUSTERFS_GLANCE=${CONFIGURE_GLUSTERFS_GLANCE:-False}
+
 # Error out when devstack-plugin-glusterfs is enabled, but not selected as a backend for cinder.
-if [ "$CONFIGURE_GLUSTERFS_CINDER" = "False" ]; then
-    echo "GlusterFS plugin enabled but not selected as a backend for Cinder."
-    echo "Please set CONFIGURE_GLUSTERFS_CINDER to True in localrc."
+if [ "$CONFIGURE_GLUSTERFS_CINDER" = "False" ] && [ "$CONFIGURE_GLUSTERFS_GLANCE" = "False" ]; then
+    echo "GlusterFS plugin enabled but not selected as a backend for Cinder or Glance."
+    echo "Please set CONFIGURE_GLUSTERFS_CINDER and/or CONFIGURE_GLUSTERFS_GLANCE to True in localrc."
     exit 1
 fi
 
@@ -67,6 +71,9 @@ GLUSTERFS_LOOPBACK_DISK_SIZE=${GLUSTERFS_LOOPBACK_DISK_SIZE:-4G}
 # By default CINDER_GLUSTERFS_SHARES="127.0.0.1:/vol1"
 CINDER_GLUSTERFS_SHARES=${CINDER_GLUSTERFS_SHARES:-"127.0.0.1:/cinder-vol"}
 
+# Glance GlusterFS share
+GLANCE_GLUSTERFS_SHARE=${GLANCE_GLUSTERFS_SHARE:-"127.0.0.1:/glance-vol"}
+
 # Adding GlusterFS repo to CentOS / RHEL 7 platform.
 GLUSTERFS_CENTOS_REPO=${GLUSTERFS_CENTOS_REPO:-"http://download.gluster.org/pub/gluster/glusterfs/LATEST/CentOS/glusterfs-epel.repo"}
 
@@ -76,6 +83,11 @@ source $GLUSTERFS_PLUGIN_DIR/gluster-functions.sh
 if [[ "$1" == "stack" && "$2" == "pre-install" ]]; then
     echo_summary "Installing GlusterFS"
     install_glusterfs
+elif [[ "$1" == "stack" && "$2" == "post-config" ]]; then
+    if is_service_enabled glance && [[ "$CONFIGURE_GLUSTERFS_GLANCE" == "True" ]]; then
+        echo_summary "Configuring GlusterFS as a backend for Glance"
+        configure_glance_backend_glusterfs
+    fi
 fi
 
 if [[ "$1" == "unstack" ]]; then

devstack/settings

@@ -14,3 +14,6 @@ CINDER_GLUSTERFS_SHARES=${CINDER_GLUSTERFS_SHARES:-"127.0.0.1:/cinder-vol1;127.0
 
 # Set default volume prov type to thick as we don't yet support backup for thin (qcow2) files
 GLUSTERFS_VOLUME_PROV_TYPE=${GLUSTERFS_VOLUME_PROV_TYPE:-thick}
+
+# Enabling GlusterFS as a backend for Glace
+CONFIGURE_GLUSTERFS_GLANCE=${CONFIGURE_GLUSTERFS_GLANCE:-True}