#!/bin/sh # # # An OCF RA that manages a symlink # # Copyright (c) 2011 Dominik Klein # # This program is free software; you can redistribute it and/or modify # it under the terms of version 2 of the GNU General Public License as # published by the Free Software Foundation. # # This program is distributed in the hope that it would be useful, but # WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. # # Further, this software is distributed without any warranty that it is # free of the rightful claim of any third person regarding infringement # or the like. Any license provided herein, whether implied or # otherwise, applies only to this software file. Patent licenses, if # any, provided herein do not apply to combinations of this program with # other software, or any other product whatsoever. # # You should have received a copy of the GNU General Public License # along with this program; if not, write the Free Software Foundation, # Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. # ####################################################################### # Initialization: : ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat} . ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs ####################################################################### meta_data() { cat < 1.1 This resource agent that manages a symbolic link (symlink). It is primarily intended to manage configuration files which should be enabled or disabled based on where the resource is running, such as cron job definitions and the like. Manages a symbolic link Full path of the symbolic link to be managed. This must obviously be in a filesystem that supports symbolic links. Full path of the symlink Full path to the link target (the file or directory which the symlink points to). Full path to the link target A suffix to append to any files that the resource agent moves out of the way because they clash with "link". If this is unset (the default), then the resource agent will simply refuse to create a symlink if it clashes with an existing file. Suffix to append to backup files END } symlink_monitor() { # This applies the following logic: # # * If $OCF_RESKEY_link does not exist, then the resource is # definitely stopped. # # * If $OCF_RESKEY_link exists and is a symlink that points to # ${OCF_RESKEY_target}, then the resource is definitely started. # # * If $OCF_RESKEY_link exists, but is anything other than a # symlink to ${OCF_RESKEY_target}, then the status depends on whether # ${OCF_RESKEY_backup_suffix} is set: # # - if ${OCF_RESKEY_backup_suffix} is set, then the resource is # simply not running. The existing file will be moved out of # the way, to ${OCF_RESKEY_link}${OCF_RESKEY_backup_suffix}, # when the resource starts. # # - if ${OCF_RESKEY_backup_suffix} is not set, then an existing # file ${OCF_RESKEY_link} is an error condition, and the # resource can't start here. rc=$OCF_ERR_GENERIC # Using ls here instead of "test -e", as "test -e" returns false # if the file does exist, but it a symlink to a file that doesn't if ! ls "$OCF_RESKEY_link" >/dev/null 2>&1; then ocf_log debug "$OCF_RESKEY_link does not exist" rc=$OCF_NOT_RUNNING elif [ ! -L "$OCF_RESKEY_link" ]; then if [ -z "$OCF_RESKEY_backup_suffix" ]; then ocf_exit_reason "$OCF_RESKEY_link exists but is not a symbolic link!" exit $OCF_ERR_INSTALLED else ocf_log debug "$OCF_RESKEY_link exists but is not a symbolic link, will be moved to ${OCF_RESKEY_link}${OCF_RESKEY_backup_suffix} on start" rc=$OCF_NOT_RUNNING fi elif readlink -m "$OCF_RESKEY_link" | egrep -q "^${OCF_RESKEY_target}$"; then ocf_log debug "$OCF_RESKEY_link exists and is a symbolic link to ${OCF_RESKEY_target}." rc=$OCF_SUCCESS else if [ -z "$OCF_RESKEY_backup_suffix" ]; then ocf_exit_reason "$OCF_RESKEY_link does not point to ${OCF_RESKEY_target}!" exit $OCF_ERR_INSTALLED else ocf_log debug "$OCF_RESKEY_link does not point to ${OCF_RESKEY_target}, will be moved to ${OCF_RESKEY_link}${OCF_RESKEY_backup_suffix} on start" rc=$OCF_NOT_RUNNING fi fi return $rc } symlink_start() { if ! symlink_monitor; then if [ -e "$OCF_RESKEY_link" ]; then if [ -z "$OCF_RESKEY_backup_suffix" ]; then # Shouldn't happen, because symlink_monitor should # have errored out. But there is a chance that # something else put that file there after # symlink_monitor ran. ocf_exit_reason "$OCF_RESKEY_link exists and no backup_suffix is set, won't overwrite." exit $OCF_ERR_GENERIC else ocf_log debug "Found $OCF_RESKEY_link, moving to ${OCF_RESKEY_link}${OCF_RESKEY_backup_suffix}" ocf_run mv -v "$OCF_RESKEY_link" "${OCF_RESKEY_link}${OCF_RESKEY_backup_suffix}" \ || exit $OCF_ERR_GENERIC fi fi ocf_run ln -sv "$OCF_RESKEY_target" "$OCF_RESKEY_link" symlink_monitor return $? else return $OCF_SUCCESS fi } symlink_stop() { if symlink_monitor; then ocf_run rm -vf "$OCF_RESKEY_link" || exit $OCF_ERR_GENERIC if ! symlink_monitor; then if [ -e "${OCF_RESKEY_link}${OCF_RESKEY_backup_suffix}" ]; then ocf_log debug "Found backup ${OCF_RESKEY_link}${OCF_RESKEY_backup_suffix}, moving to $OCF_RESKEY_link" # if restoring the backup fails then still return with # $OCF_SUCCESS, but log a warning ocf_run -warn mv "${OCF_RESKEY_link}${OCF_RESKEY_backup_suffix}" "$OCF_RESKEY_link" fi return $OCF_SUCCESS else ocf_exit_reason "Removing $OCF_RESKEY_link failed." return $OCF_ERR_GENERIC fi else return $OCF_SUCCESS fi } symlink_validate_all() { if [ "x${OCF_RESKEY_link}" = "x" ]; then ocf_exit_reason "Mandatory parameter link is unset" exit $OCF_ERR_CONFIGURED fi if [ "x${OCF_RESKEY_target}" = "x" ]; then ocf_exit_reason "Mandatory parameter target is unset" exit $OCF_ERR_CONFIGURED fi # Having a non-existant target is technically not an error, as # symlinks are allowed to point to non-existant paths. But it # still doesn't hurt to warn people if the target does not exist # (but only during non-probes). if [ ! -e "${OCF_RESKEY_target}" ]; then ocf_log warn "${OCF_RESKEY_target} does not exist!" fi } symlink_usage() { cat <