#!/bin/bash
 #

 # lib/cinder_backends/lvm
 # Configure the LVM backend
 
 # Enable with:
 #
 #   CINDER_ENABLED_BACKENDS+=,lvm:lvmname
 
 # Dependencies:
 #
 # - ``functions`` file
 # - ``cinder`` configurations
 
 # CINDER_CONF
 # DATA_DIR
 
 # clean_cinder_backend_lvm - called from clean_cinder()
 # configure_cinder_backend_lvm - called from configure_cinder()
 # init_cinder_backend_lvm - called from init_cinder()
 
 
 # Save trace setting
 MY_XTRACE=$(set +o | grep xtrace)
 set +o xtrace
 
 
 # Defaults
 # --------
 
 # Name of the lvm volume groups to use/create for iscsi volumes
 # This monkey-motion is for compatibility with icehouse-generation Grenade
 # If ``VOLUME_GROUP`` is set, use it, otherwise we'll build a VG name based
 # on ``VOLUME_GROUP_NAME`` that includes the backend name
 # Grenade doesn't use ``VOLUME_GROUP2`` so it is left out
 VOLUME_GROUP_NAME=${VOLUME_GROUP:-${VOLUME_GROUP_NAME:-stack-volumes}}
 
 # TODO: resurrect backing device...need to know how to set values
 #VOLUME_BACKING_DEVICE=${VOLUME_BACKING_DEVICE:-}
 
 VOLUME_NAME_PREFIX=${VOLUME_NAME_PREFIX:-volume-}
 
 
 # Entry Points
 # ------------
 
 # Compatibility for getting a volume group name from either ``VOLUME_GROUP``
 # or from ``VOLUME_GROUP_NAME`` plus the backend name
 function get_volume_group_name {
     local be_name=$1
 
     # Again with the icehouse-generation compatibility
     local volume_group_name=$VOLUME_GROUP_NAME
     if [[ -z $VOLUME_GROUP ]]; then
         volume_group_name+="-$be_name"
     fi
     echo $volume_group_name
 }
 
 function cleanup_cinder_backend_lvm {
     local be_name=$1
 
     # Again with the icehouse-generation compatibility
     local volume_group_name=$(get_volume_group_name $be_name)
 
     # Campsite rule: leave behind a volume group at least as clean as we found it
     _clean_lvm_lv ${volume_group_name} $VOLUME_NAME_PREFIX
     _clean_lvm_backing_file ${volume_group_name} $DATA_DIR/${volume_group_name}-backing-file
 }
 
 # configure_cinder_backend_lvm - Set config files, create data dirs, etc
 # configure_cinder_backend_lvm $name
 function configure_cinder_backend_lvm {
     local be_name=$1
 
     # Again with the icehouse-generation compatibility
     local volume_group_name=$(get_volume_group_name $be_name)
 
     iniset $CINDER_CONF $be_name volume_backend_name $be_name
     iniset $CINDER_CONF $be_name volume_driver "cinder.volume.drivers.lvm.LVMISCSIDriver"
     iniset $CINDER_CONF $be_name volume_group $volume_group_name
 
     if [[ "$CINDER_SECURE_DELETE" == "False" ]]; then
         iniset $CINDER_CONF $be_name volume_clear none
     fi
 }
 
 
 function init_cinder_backend_lvm {
     local be_name=$1
 
     # Again with the icehouse-generation compatibility
     local volume_group_name=$(get_volume_group_name $be_name)
 
     # Start with a clean volume group
     _create_cinder_volume_group ${volume_group_name} $DATA_DIR/${volume_group_name}-backing-file
 
     if is_fedora || is_suse; then
         # service is not started by default
         start_service tgtd
     fi
 
     # Remove iscsi targets
     sudo tgtadm --op show --mode target | grep $VOLUME_NAME_PREFIX | grep Target | cut -f3 -d ' ' | sudo xargs -n1 tgt-admin --delete || true
     _clean_lvm_lv ${volume_group_name} $VOLUME_NAME_PREFIX
 }
 
 
 # _clean_lvm_lv removes all cinder LVM volumes
 #
 # Usage: _clean_lvm_lv volume-group-name $VOLUME_NAME_PREFIX
 function _clean_lvm_lv {
     local vg=$1
     local lv_prefix=$2
 
     # Clean out existing volumes

     local lv

     for lv in $(sudo lvs --noheadings -o lv_name $vg 2>/dev/null); do
         # lv_prefix prefixes the LVs we want
         if [[ "${lv#$lv_prefix}" != "$lv" ]]; then
             sudo lvremove -f $vg/$lv
         fi
     done
 }
 
 # _clean_lvm_backing_file() removes the backing file of the
 # volume group used by cinder
 #
 # Usage: _clean_lvm_backing_file() volume-group-name backing-file-name
 function _clean_lvm_backing_file {
     local vg=$1
     local backing_file=$2
 
     # if there is no logical volume left, it's safe to attempt a cleanup
     # of the backing file
     if [[ -z "$(sudo lvs --noheadings -o lv_name $vg 2>/dev/null)" ]]; then
         # if the backing physical device is a loop device, it was probably setup by devstack

         local vg_dev=$(sudo losetup -j $backing_file | awk -F':' '/backing-file/ { print $1}')
         if [[ -n "$vg_dev" ]] && [[ -e "$vg_dev" ]]; then
             sudo losetup -d $vg_dev

             rm -f $backing_file
         fi
     fi
 }
 
 # _create_cinder_volume_group volume-group-name backing-file-name
 function _create_cinder_volume_group {
     # According to the ``CINDER_MULTI_LVM_BACKEND`` value, configure one or two default volumes
     # group called ``stack-volumes`` (and ``stack-volumes2``) for the volume
     # service if it (they) does (do) not yet exist. If you don't wish to use a
     # file backed volume group, create your own volume group called ``stack-volumes``
     # and ``stack-volumes2`` before invoking ``stack.sh``.
     #
     # The two backing files are ``VOLUME_BACKING_FILE_SIZE`` in size, and they are stored in
     # the ``DATA_DIR``.
 
     local vg_name=$1
     local backing_file=$2
 
     if ! sudo vgs $vg_name; then
         # TODO: fix device handling
         if [ -z "$VOLUME_BACKING_DEVICE" ]; then
             # Only create if the file doesn't already exists
             [[ -f $backing_file ]] || truncate -s $VOLUME_BACKING_FILE_SIZE $backing_file

             local vg_dev=`sudo losetup -f --show $backing_file`

 
             # Only create if the loopback device doesn't contain $VOLUME_GROUP
             if ! sudo vgs $vg_name; then

                 sudo vgcreate $vg_name $vg_dev

             fi
         else
             sudo vgcreate $vg_name $VOLUME_BACKING_DEVICE
         fi
     fi
 }
 
 
 # Restore xtrace
 $MY_XTRACE
 
 # mode: shell-script
 # End: