#!/bin/sh
#
#   OCF resource agent for mapping and unmapping
#   RADOS Block Devices (RBDs)
#
#   License:      GNU Lesser General Public License (LGPL) 2.1
#   (c) 2012 Florian Haas, hastexo
#

# Initialization:
: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat}
. ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs

# Convenience variables
# When sysconfdir isn't passed in as a configure flag,
# it's defined in terms of prefix
prefix=@prefix@

# Defaults
OCF_RESKEY_pool_default="rbd"
OCF_RESKEY_cephconf_default="@sysconfdir@/@PACKAGE_TARNAME@/@PACKAGE_TARNAME@.conf"
: ${OCF_RESKEY_pool=${OCF_RESKEY_pool_default}}
: ${OCF_RESKEY_cephconf=${OCF_RESKEY_cephconf_default}}

rbd_meta_data() {
    cat <<EOF
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="rbd" version="0.1">
  <version>0.1</version>
  <longdesc lang="en">
Manages RADOS Block Devices (RBDs) as a highly available
resource. Maps and unmaps RBDs as needed.
  </longdesc>
  <shortdesc lang="en">Maps and unmaps RADOS Block Devices</shortdesc>
  <parameters>
    <parameter name="name" unique="0" required="1">
      <longdesc lang="en">
      Name of the RBD device.
      </longdesc>
      <shortdesc lang="en">RBD device name</shortdesc>
      <content type="string"/>
    </parameter>
    <parameter name="pool" unique="0" required="0">
      <longdesc lang="en">
      Name of the RADOS pool where the RBD has been created
      </longdesc>
      <shortdesc lang="en">RADOS pool name</shortdesc>
      <content type="string" default="${OCF_RESKEY_pool_default}"/>
    </parameter>
    <parameter name="snap" unique="0" required="0">
      <longdesc lang="en">
      Name of the device snapshot to map.
      </longdesc>
      <shortdesc lang="en">Snapshot name</shortdesc>
      <content type="string"/>
    </parameter>
    <parameter name="cephconf" unique="0" required="0">
      <longdesc lang="en">
      Location of the Ceph configuration file
      </longdesc>
      <shortdesc lang="en">Ceph configuration file</shortdesc>
      <content type="string" default="${OCF_RESKEY_cephconf_default}"/>
    </parameter>
    <parameter name="mon" unique="0" required="0">
      <longdesc lang="en">
      Address (or comma-separated list of addresses) of
      monitor servers to connect to. Overrides values from
      configuration file.
      </longdesc>
      <shortdesc lang="en">Monitor address(es)</shortdesc>
      <content type="string"/>
    </parameter>
    <parameter name="user" unique="0" required="0">
      <longdesc lang="en">
      Username to use when mapping the device. Required
      if Ceph authentication is enabled on the monitor.
      </longdesc>
      <shortdesc lang="en">Authentication username</shortdesc>
      <content type="string"/>
    </parameter>
    <parameter name="secret" unique="0" required="0">
      <longdesc lang="en">
      File containing an authentication secret. Required
      if Ceph authentication is enabled on the monitor.
      </longdesc>
      <shortdesc lang="en">Authentication secret file</shortdesc>
      <content type="string"/>
    </parameter>
  </parameters>
  <actions>
    <action name="start"        timeout="20" />
    <action name="stop"         timeout="20" />
    <action name="monitor"      timeout="20"
                                interval="10" depth="0" />
    <action name="meta-data"    timeout="5" />
    <action name="validate-all"   timeout="20" />
  </actions>
</resource-agent>
EOF
}

rbd_usage() {
        cat <<EOF
usage: $0 {start|stop|status|monitor|validate-all|meta-data}

Expects to have a fully populated OCF RA-compliant environment set.
EOF
}

# rbd command wrapper: builds an option string for invoking RBD based
# on resource parameters, and invokes rbd through ocf_run.
do_rbd() {
    local rbd_options

    if [ -n "${OCF_RESKEY_cephconf}" ]; then
        rbd_options="$rbd_options -c ${OCF_RESKEY_cephconf}"
    fi
    if [ -n "${OCF_RESKEY_mon}" ]; then
        rbd_options="$rbd_options -m ${OCF_RESKEY_mon}"
    fi

    ocf_run rbd $rbd_options $@
}

# Convenience function that uses "rbd showmapped" to retrieve the
# mapped device name from the pool, RBD name, and snapshot.
find_rbd_dev() {
    local sedpat

    # Example output from "rbd showmapped" (tab separated):
    # id        pool    image   snap    device
    # 0         rbd     test    -       /dev/rbd0

    # Build the sed pattern, substituting "-" for the snapshot name if
    # it's unset
    sedpat="[0-9]\+[ \t]\+${OCF_RESKEY_pool}[ \t]\+${OCF_RESKEY_name}[ \t]\+${OCF_RESKEY_snap:--}[ \t]\+\(/dev/rbd[0-9]\+\).*"

    # Run rbd showmapped, filter out the header line, then try to
    # extract the device name
    rbd showmapped | tail -n +2 | sed -n -e "s,$sedpat,\1,p"
}

rbd_validate_all() {
    # Test for configuration errors first
    if [ -z "$OCF_RESKEY_name" ]; then
       ocf_log err 'Required parameter "name" is unset!'
       exit $OCF_ERR_CONFIGURED
    fi

    # Test for required binaries
    check_binary rbd

    return $OCF_SUCCESS
}

rbd_monitor() {
    local rc
    local rbd_dev

    if ! [ -d /sys/bus/rbd ]; then
        ocf_log debug "rbd module is not loaded"
        return $OCF_NOT_RUNNING
    fi

    rbd_dev=`find_rbd_dev`

    if [ -z "$rbd_dev" ]; then
        ocf_log debug "RBD device is unmapped"
        rc=$OCF_NOT_RUNNING
    elif [ -b "$rbd_dev" ]; then
        ocf_log debug "RBD device is mapped to $rbd_dev"
        rc=$OCF_SUCCESS
    else
        # Device is listed, but the corresponding path is not a block
        # device.
        ocf_log err "$rbd_dev is not a block device!"
        rc=$OCF_ERR_GENERIC
    fi

    return $rc
}

rbd_start() {
    local rbd_map_options
    local rbd_name

    # if resource is already running, bail out early
    if rbd_monitor; then
        ocf_log info "Resource is already running"
        return $OCF_SUCCESS
    fi

    # actually start up the resource here (make sure to immediately
    # exit with an $OCF_ERR_ error code if anything goes seriously
    # wrong)

    if [ ! -d /sys/bus/rbd ]; then
        ocf_run modprobe -v rbd || exit $OCF_ERR_INSTALLED
    fi

    if [ -n "${OCF_RESKEY_user}" ]; then
        rbd_map_options="--id ${OCF_RESKEY_user}"
    fi
    if [ -n "${OCF_RESKEY_secret}" ]; then
        rbd_map_options="$rbd_map_options --keyfile ${OCF_RESKEY_secret}"
    fi

    rbd_name="${OCF_RESKEY_pool}/${OCF_RESKEY_name}"
    if [ -n "${OCF_RESKEY_snap}" ]; then
        rbd_name="$rbd_name@${OCF_RESKEY_snap}"
    fi

    do_rbd map $rbd_name $rbd_map_options || exit $OCF_ERR_GENERIC

    # After the resource has been started, check whether it started up
    # correctly. If the resource starts asynchronously, the agent may
    # spin on the monitor function here -- if the resource does not
    # start up within the defined timeout, the cluster manager will
    # consider the start action failed
    while ! rbd_monitor; do
        ocf_log debug "Resource has not started yet, waiting"
        sleep 1
    done

    # only return $OCF_SUCCESS if _everything_ succeeded as expected
    return $OCF_SUCCESS
}

rbd_stop() {
    local rc
    local rbd_dev

    rbd_monitor
    rc=$?
    case "$rc" in
        "$OCF_SUCCESS")
            # Currently running. Normal, expected behavior.
            ocf_log debug "Resource is currently running"
            ;;
        "$OCF_NOT_RUNNING")
            # Currently not running. Nothing to do.
            ocf_log info "Resource is already stopped"
            return $OCF_SUCCESS
            ;;
    esac

    # actually shut down the resource here (make sure to immediately
    # exit with an $OCF_ERR_ error code if anything goes seriously
    # wrong)
    rbd_dev=`find_rbd_dev`
    do_rbd unmap $rbd_dev || exit $OCF_ERR_GENERIC

    # After the resource has been stopped, check whether it shut down
    # correctly. If the resource stops asynchronously, the agent may
    # spin on the monitor function here -- if the resource does not
    # shut down within the defined timeout, the cluster manager will
    # consider the stop action failed
    while rbd_monitor; do
        ocf_log debug "Resource has not stopped yet, waiting"
        sleep 1
    done

    # only return $OCF_SUCCESS if _everything_ succeeded as expected
    return $OCF_SUCCESS

}

# Make sure meta-data and usage always succeed
case $__OCF_ACTION in
meta-data)      rbd_meta_data
                exit $OCF_SUCCESS
                ;;
usage|help)     rbd_usage
                exit $OCF_SUCCESS
                ;;
esac

# Anything other than meta-data and usage must pass validation
rbd_validate_all || exit $?

# Translate each action into the appropriate function call
case $__OCF_ACTION in
start)          rbd_start;;
stop)           rbd_stop;;
status|monitor) rbd_monitor;;
validate-all)   ;;
*)              rbd_usage
                exit $OCF_ERR_UNIMPLEMENTED
                ;;
esac
rc=$?

# The resource agent may optionally log a debug message
ocf_log debug "${OCF_RESOURCE_INSTANCE} $__OCF_ACTION returned $rc"
exit $rc