#!/bin/sh

# Event script for ctdb-specific setup and other things that don't fit
# elsewhere.

[ -n "$CTDB_BASE" ] || \
    CTDB_BASE=$(d=$(dirname "$0") ; cd -P "$d" ; dirname "$PWD")

. "${CTDB_BASE}/functions"

loadconfig

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

# type is commonly supported and more portable than which(1)
# shellcheck disable=SC2039
select_tdb_checker ()
{
    # Find the best TDB consistency check available.
    use_tdb_tool_check=false
    type tdbtool >/dev/null 2>&1 && found_tdbtool=true
    type tdbdump >/dev/null 2>&1 && found_tdbdump=true

    if $found_tdbtool && echo "help" | tdbtool | grep -q check ; then
	    use_tdb_tool_check=true
    elif $found_tdbtool && $found_tdbdump ; then
	    cat <<EOF
WARNING: The installed 'tdbtool' does not offer the 'check' subcommand.
 Using 'tdbdump' for database checks.
 Consider updating 'tdbtool' for better checks!
EOF
    elif $found_tdbdump ; then
	cat <<EOF
WARNING: 'tdbtool' is not available.
 Using 'tdbdump' to check the databases.
 Consider installing a recent 'tdbtool' for better checks!
EOF
    else
	cat <<EOF
WARNING: Cannot check databases since neither
 'tdbdump' nor 'tdbtool check' is available.
 Consider installing tdbtool or at least tdbdump!
EOF
        return 1
    fi
}

check_tdb ()
{
    _db="$1"

    if $use_tdb_tool_check ; then
	# tdbtool always exits with 0  :-(
	if timeout 10 tdbtool "$_db" check 2>/dev/null |
	    grep -q "Database integrity is OK" ; then
	    return 0
	else
	    return 1
	fi
    else
	timeout 10 tdbdump "$_db" >/dev/null 2>/dev/null
	return $?
    fi
}

check_persistent_databases ()
{
    _dir="${CTDB_DBDIR_PERSISTENT:-${CTDB_DBDIR:-${CTDB_VARDIR}}/persistent}"
    [ -d "$_dir" ] || return 0

    [ "${CTDB_MAX_PERSISTENT_CHECK_ERRORS:-0}" = "0" ] || return 0

    for _db in "$_dir/"*.tdb.*[0-9] ; do
	[ -r "$_db" ] || continue
	check_tdb "$_db" || \
	    die "Persistent database $_db is corrupted! CTDB will not start."
    done
}

check_non_persistent_databases ()
{
    _dir="${CTDB_DBDIR:-${CTDB_VARDIR}}"
    [ -d "$_dir" ] || return 0

    for _db in "${_dir}/"*.tdb.*[0-9] ; do
	[ -r "$_db" ] || continue
	check_tdb "$_db" || {
	    _backup="${_db}.$(date +'%Y%m%d.%H%M%S.%N').corrupt"
	    cat <<EOF
WARNING: database ${_db} is corrupted.
 Moving to backup ${_backup} for later analysis.
EOF
	    mv "$_db" "$_backup"

	    # Now remove excess backups
	    _max="${CTDB_MAX_CORRUPT_DB_BACKUPS:-10}"
	    _bdb="${_db##*/}" # basename
	    find "$_dir" -name "${_bdb}.*.corrupt" |
		    sort -r |
		    tail -n +$((_max + 1)) |
		    xargs rm -f
	}
    done
}

set_ctdb_variables ()
{
    # set any tunables from the config file
    set | sed -n '/^CTDB_SET_/s/=.*//p' |
    while read v; do
	varname="${v#CTDB_SET_}"
	value=$(eval echo "\$$v")
	if $CTDB setvar "$varname" "$value" ; then
	    echo "Set $varname to $value"
	else
	    echo "Invalid configuration: CTDB_SET_${varname}=${value}"
	    return 1
	fi
    done
}

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

ctdb_check_args "$@"

case "$1" in
init)
        # make sure we have a blank state directory for the scripts to work with
	rm -rf "$CTDB_SCRIPT_VARDIR"
	mkdir -p "$CTDB_SCRIPT_VARDIR" || \
	    die "mkdir -p ${CTDB_SCRIPT_VARDIR} - failed - $?" $?

	if select_tdb_checker ; then
	    check_persistent_databases || exit $?
	    check_non_persistent_databases
	fi
	;;

setup)
	# Set any tunables from the config file
	set_ctdb_variables || \
	    die "Aborting setup due to invalid configuration - fix typos, remove unknown tunables"
	;;

startup)
	$CTDB attach ctdb.tdb persistent
	;;
esac

# all OK
exit 0