#!/bin/sh

if [ -z "$CTDB_BASE" ] ; then
	export CTDB_BASE="/usr/local/etc/ctdb"
fi

. "${CTDB_BASE}/functions"
loadconfig "ctdb"

# Default LVS nodes file location
[ -n "$CTDB_LVS_NODES" ] || CTDB_LVS_NODES="${CTDB_BASE}/lvs_nodes"

[ -n "$CTDB_SOCKET" ] && export CTDB_SOCKET

############################################################

usage ()
{
	cat <<EOF
$0 <option>

<option> is one of:
  master     Display node number of master node
  list       List node number and private IP address of usable nodes in group
  status     Show status of all nodes in LVS group
EOF
    exit 1
}

nodestatus_X=""
# Fields are:
# Node|IP|Disconnected|Banned|Disabled|Unhealthy|Stopped|Inactive|PartiallyOnline|ThisNode
get_nodestatus_X ()
{
	# Result is cached in global variable nodestatus_X
	[ -n "$nodestatus_X" ] || \
		nodestatus_X=$(ctdb -X nodestatus all |
			       sed -e '1d' -e 's@^|@@' -e 's@|$@@')
}

get_nodestatus ()
{
	# Result is cached in global variable nodestatus
	[ -n "$nodestatus" ] || nodestatus=$(ctdb nodestatus all)
	case $? in
	# ctdb nodestatus returns 255 on failure
	0|255) return 0 ;;
	*)     return 1 ;;
	esac
}

get_lvs_nodes ()
{
	# Result is cached in global variable lvs_nodes
	if [ -n "$lvs_nodes" ] ; then
		return
	fi

	if [ ! -r "$CTDB_LVS_NODES" ] ; then
		return 1
	fi

	lvs_nodes=$(cat "$CTDB_LVS_NODES") || return 1

	# Sanity check file contents here
	while read _ip _options ; do
		# Skip comments
		case "$_ip" in
		\#*) continue ;;
		esac
		case "$_options" in
		slave-only|"") : ;;
		*) die "${prog}: Invalid options \"${_options}\" in  \"$CTDB_LVS_NODES\""
		esac
	done <<EOF
$lvs_nodes
EOF

	return 0
}

# Print PNN and IP address of given nodes meeting the criteria for
# usable LVS nodes.  That is, either those that are healthy or, if no
# healthy nodes, then nodes that are active and not-disabled.
# Return codes: 0 = nodes found, 255 = no nodes found, 10 = error.
filter_nodes ()
{
	# $_ns is an @-delimited list of nodes to be considered
	_ns="$1"

	get_nodestatus_X
	[ -n "$nodestatus_X" ] || return 10

	# Now filter by $_ns and by status of nodes...

	# Note that the 2 awk invocations below have "||" between
	# them, so the first to succeed will print the nodes.

	# First try for a fully active and healthy node, so must not
	# be DISABLED, UNHEALTHY or INACTIVE (last covers
	# DISCONNECTED, BANNED or STOPPED)
	awk -F '|' -v ns="$_ns" '
		BEGIN { ret = 255 }
		ns ~ "@" $2 "@" && $5 == 0 && $6 == 0 && $8 == 0 {
			print $1, $2 ; ret=0
		}
		END { exit ret }
		' <<EOF ||
$nodestatus_X
EOF
	# Not found?  UNHEALTHY do, so node must not be INACTIVE or
	# DISABLED
	awk -F '|' -v ns="$_ns" '
		BEGIN { ret = 255 }
		ns ~ "@" $2 "@" && $5 == 0 && $8 == 0 {
			print $1, $2 ; ret=0
		}
		END { exit ret }
		' <<EOF
$nodestatus_X
EOF
}

# Print the PNN of the LVS master node
find_master ()
{
	get_lvs_nodes || \
		die "${prog}: LVS nodes file \"$CTDB_LVS_NODES\" not found"

	# $_ms is an @-delimited list of nodes that are allowed to be the master
	_ms="@"
	while read _ip _options ; do
		case "$_options" in
		"") _ms="${_ms}${_ip}@" ;;
		esac
	done <<EOF
$lvs_nodes
EOF

	_master_candidates=$(filter_nodes "$_ms") || return $?
	echo "${_master_candidates%% *}"
}

# Print the PNN of the LVS master node, verbose version
show_master ()
{
	_master_pnn=$(find_master)
	case "$?" in
	0)
		echo "Node ${_master_pnn} is LVS master"
		exit 0
		;;
	255)
		echo "There is no LVS master"
		exit 255
		;;
	*)
		exit 10
		;;
	esac
}

# List all usable nodes in the LVS group
nodes_list ()
{
	get_lvs_nodes || \
		die "${prog}: LVS nodes file \"$CTDB_LVS_NODES\" not found"

	# $_ns is a @-delimited list of nodes in the LVS  group
	_ns="@"
	while read _ip _options ; do
		_ns="${_ns}${_ip}@"
	done <<EOF
$lvs_nodes
EOF

	_usable_nodes=$(filter_nodes "$_ns")
	case $? in
	0)   : ;;
	255) exit 0 ;; # Return 0 even if no usable nodes
	*)   exit 10 ;;
	esac

	awk '{ print $1 ":" $2 }'<<EOF
$_usable_nodes
EOF
}

# Print the status of all nodes in the LVS group, along with a count
nodes_status ()
{
	get_lvs_nodes || \
		die "${prog}: LVS nodes file \"$CTDB_LVS_NODES\" not found"
	get_nodestatus
	[ -n "$nodestatus" ] || exit 10

	# $_ns is a @-delimited list of nodes in the LVS  group
	_ns="@"
	while read _ip _options ; do
		_ns="${_ns}${_ip}@"
	done <<EOF
$lvs_nodes
EOF

	# Print status of nodes in $_ns, along with node count
	awk -v ns="$_ns" 'ns ~ "@" $2 "@" { print }' <<EOF
$nodestatus
EOF
}

# For backward compatibility
prog=$(basename "$0")
cmd="$1"

case "$cmd" in
master) show_master ;;
list)   nodes_list ;;
status) nodes_status ;;
*)      usage ;;
esac