#!/usr/bin/sh
#
#
# MySQL
#
# Description:  Manages a MySQL database as Linux-HA resource
#
# Authors:  Alan Robertson:               DB2 Script
#           Jakub Janczak:                rewrite as MySQL
#           Andrew Beekhof:               cleanup and import
#           Sebastian Reitenbach:         add OpenBSD defaults, more cleanup
#           Narayan Newton:               add Gentoo/Debian defaults
#           Marian Marinov, Florian Haas: add replication capability
#           Yves Trudeau, Baron Schwartz: add VIP support and improve replication
#
# Support:  users@clusterlabs.org
# License:  GNU General Public License (GPL)
#
# (c) 2002-2005 International Business Machines, Inc.
#     2005-2010 Linux-HA contributors
#
# An example usage in /etc/ha.d/haresources:
#       node1  10.0.0.170 mysql
#
# See usage() function below for more details...
#
# OCF instance parameters:
#   OCF_RESKEY_binary
#   OCF_RESKEY_client_binary
#   OCF_RESKEY_config
#   OCF_RESKEY_datadir
#   OCF_RESKEY_user
#   OCF_RESKEY_group
#   OCF_RESKEY_test_table
#   OCF_RESKEY_test_user
#   OCF_RESKEY_test_passwd
#   OCF_RESKEY_enable_creation
#   OCF_RESKEY_additional_parameters
#   OCF_RESKEY_log
#   OCF_RESKEY_pid
#   OCF_RESKEY_socket
#   OCF_RESKEY_replication_user
#   OCF_RESKEY_replication_passwd
#   OCF_RESKEY_replication_port
#   OCF_RESKEY_max_slave_lag
#   OCF_RESKEY_evict_outdated_slaves
#   OCF_RESKEY_reader_attribute

#######################################################################
# Initialization:

: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat}
. ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs
. ${OCF_FUNCTIONS_DIR}/mysql-common.sh
#######################################################################

usage() {
  cat <<UEND
usage: $0 (start|stop|validate-all|meta-data|monitor|promote|demote|notify)

$0 manages a MySQL Database as an HA resource.

The 'start' operation starts the database.
The 'stop' operation stops the database.
The 'status' operation reports whether the database is running
The 'monitor' operation reports whether the database seems to be working
The 'promote' operation makes this mysql server run as master
The 'demote' operation makes this mysql server run as slave
The 'validate-all' operation reports whether the parameters are valid

UEND
}

meta_data() {
   cat <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="mysql" version="1.0">
<version>1.0</version>

<longdesc lang="en">
Resource script for MySQL.
May manage a standalone MySQL database, a clone set with externally
managed replication, or a complete master/slave replication setup.
Note, when master/slave replication is in use, the resource must
be setup to use notifications. Set 'notify=true' in the metadata
attributes when defining a MySQL master/slave instance.

While managing replication, the default behavior is to use uname -n
values in the change master to command.  Other IPs can be specified
manually by adding a node attribute \${INSTANCE_ATTR_NAME}_mysql_master_IP
giving the IP to use for replication.  For example, if the mysql primitive
you are using is p_mysql, the attribute to set will be
p_mysql_mysql_master_IP.
</longdesc>
<shortdesc lang="en">Manages a MySQL database instance</shortdesc>
<parameters>

<parameter name="binary" unique="0" required="0">
<longdesc lang="en">
Location of the MySQL server binary
</longdesc>
<shortdesc lang="en">MySQL server binary</shortdesc>
<content type="string" default="${OCF_RESKEY_binary_default}" />
</parameter>

<parameter name="client_binary" unique="0" required="0">
<longdesc lang="en">
Location of the MySQL client binary
</longdesc>
<shortdesc lang="en">MySQL client binary</shortdesc>
<content type="string" default="${OCF_RESKEY_client_binary_default}" />
</parameter>

<parameter name="config" unique="0" required="0">
<longdesc lang="en">
Configuration file
</longdesc>
<shortdesc lang="en">MySQL config</shortdesc>
<content type="string" default="${OCF_RESKEY_config_default}" />
</parameter>

<parameter name="datadir" unique="0" required="0">
<longdesc lang="en">
Directory containing databases
</longdesc>
<shortdesc lang="en">MySQL datadir</shortdesc>
<content type="string" default="${OCF_RESKEY_datadir_default}" />
</parameter>

<parameter name="user" unique="0" required="0">
<longdesc lang="en">
User running MySQL daemon
</longdesc>
<shortdesc lang="en">MySQL user</shortdesc>
<content type="string" default="${OCF_RESKEY_user_default}" />
</parameter>

<parameter name="group" unique="0" required="0">
<longdesc lang="en">
Group running MySQL daemon (for logfile and directory permissions)
</longdesc>
<shortdesc lang="en">MySQL group</shortdesc>
<content type="string" default="${OCF_RESKEY_group_default}"/>
</parameter>

<parameter name="log" unique="0" required="0">
<longdesc lang="en">
The logfile to be used for mysqld.
</longdesc>
<shortdesc lang="en">MySQL log file</shortdesc>
<content type="string" default="${OCF_RESKEY_log_default}"/>
</parameter>

<parameter name="pid" unique="0" required="0">
<longdesc lang="en">
The pidfile to be used for mysqld.
</longdesc>
<shortdesc lang="en">MySQL pid file</shortdesc>
<content type="string" default="${OCF_RESKEY_pid_default}"/>
</parameter>

<parameter name="socket" unique="0" required="0">
<longdesc lang="en">
The socket to be used for mysqld.
</longdesc>
<shortdesc lang="en">MySQL socket</shortdesc>
<content type="string" default="${OCF_RESKEY_socket_default}"/>
</parameter>

<parameter name="test_table" unique="0" required="0">
<longdesc lang="en">
Table to be tested in monitor statement (in database.table notation)
</longdesc>
<shortdesc lang="en">MySQL test table</shortdesc>
<content type="string" default="${OCF_RESKEY_test_table_default}" />
</parameter>

<parameter name="test_user" unique="0" required="0">
<longdesc lang="en">
MySQL test user, must have select privilege on test_table
</longdesc>
<shortdesc lang="en">MySQL test user</shortdesc>
<content type="string" default="${OCF_RESKEY_test_user_default}" />
</parameter>

<parameter name="test_passwd" unique="0" required="0">
<longdesc lang="en">
MySQL test user password
</longdesc>
<shortdesc lang="en">MySQL test user password</shortdesc>
<content type="string" default="${OCF_RESKEY_test_passwd_default}" />
</parameter>

<parameter name="enable_creation" unique="0" required="0">
<longdesc lang="en">
If the MySQL database does not exist, it will be created
</longdesc>
<shortdesc lang="en">Create the database if it does not exist</shortdesc>
<content type="boolean" default="${OCF_RESKEY_enable_creation_default}"/>
</parameter>

<parameter name="additional_parameters" unique="0" required="0">
<longdesc lang="en">
Additional parameters which are passed to the mysqld on startup.
(e.g. --skip-external-locking or --skip-grant-tables)
</longdesc>
<shortdesc lang="en">Additional parameters to pass to mysqld</shortdesc>
<content type="string" default="${OCF_RESKEY_additional_parameters_default}"/>
</parameter>

<parameter name="replication_user" unique="0" required="0">
<longdesc lang="en">
MySQL replication user. This user is used for starting and stopping
MySQL replication, for setting and resetting the master host, and for
setting and unsetting read-only mode. Because of that, this user must
have SUPER, REPLICATION SLAVE, REPLICATION CLIENT, PROCESS and RELOAD
privileges on all nodes within the cluster. Mandatory if you define a
master-slave resource.
</longdesc>
<shortdesc lang="en">MySQL replication user</shortdesc>
<content type="string" default="${OCF_RESKEY_replication_user_default}" />
</parameter>

<parameter name="replication_passwd" unique="0" required="0">
<longdesc lang="en">
MySQL replication password. Used for replication client and slave.
Mandatory if you define a master-slave resource.
</longdesc>
<shortdesc lang="en">MySQL replication user password</shortdesc>
<content type="string" default="${OCF_RESKEY_replication_passwd_default}" />
</parameter>

<parameter name="replication_port" unique="0" required="0">
<longdesc lang="en">
The port on which the Master MySQL instance is listening.
</longdesc>
<shortdesc lang="en">MySQL replication port</shortdesc>
<content type="string" default="${OCF_RESKEY_replication_port_default}" />
</parameter>

<parameter name="replication_require_ssl" unique="0" required="0">
<longdesc lang="en">
Enables SSL connection to local MySQL service for replication user.
i.e. if REQUIRE SSL for replication user in MySQL set, this should be set to "true".
</longdesc>
<shortdesc lang="en">MySQL replication require ssl</shortdesc>
<content type="string" default="${OCF_RESKEY_replication_require_ssl_default}" />
</parameter>

<parameter name="replication_master_ssl_ca" unique="0" required="0">
<longdesc lang="en">
The SSL CA certificate to be used for replication over SSL.
</longdesc>
<shortdesc lang="en">MySQL replication SSL CA certificate</shortdesc>
<content type="string" default="${OCF_RESKEY_replication_master_ssl_ca_default}" />
</parameter>

<parameter name="replication_master_ssl_cert" unique="0" required="0">
<longdesc lang="en">
The SSL CA certificate to be used for replication over SSL.
</longdesc>
<shortdesc lang="en">MySQL replication SSL certificate</shortdesc>
<content type="string" default="${OCF_RESKEY_replication_master_ssl_cert_default}" />
</parameter>

<parameter name="replication_master_ssl_key" unique="0" required="0">
<longdesc lang="en">
The SSL certificate key to be used for replication over SSL.
</longdesc>
<shortdesc lang="en">MySQL replication SSL certificate key</shortdesc>
<content type="string" default="${OCF_RESKEY_replication_master_ssl_key_default}" />
</parameter>

<parameter name="max_slave_lag" unique="0" required="0">
<longdesc lang="en">
The maximum number of seconds a replication slave is allowed to lag
behind its master. Do not set this to zero. What the cluster manager
does in case a slave exceeds this maximum lag is determined by the
evict_outdated_slaves parameter.
</longdesc>
<shortdesc lang="en">Maximum time (seconds) a MySQL slave is allowed
to lag behind a master</shortdesc>
<content type="integer" default="${OCF_RESKEY_max_slave_lag_default}"/>
</parameter>

<parameter name="evict_outdated_slaves" unique="0" required="0">
<longdesc lang="en">
If set to true, any slave which is more than max_slave_lag seconds
behind the master has its MySQL instance shut down. If this parameter
is set to false in a primitive or clone resource, it is simply
ignored. If set to false in a master/slave resource, then exceeding
the maximum slave lag will merely push down the master preference so
the lagging slave is never promoted to the new master.
</longdesc>
<shortdesc lang="en">Determines whether to shut down badly lagging
slaves</shortdesc>
<content type="boolean" default="${OCF_RESKEY_evict_outdated_slaves_default}" />
</parameter>

<parameter name="reader_attribute" unique="1" required="0">
<longdesc lang="en">
An attribute that the RA can manage to specify whether a node
can be read from. This node attribute will be 1 if it's fine to
read from the node, and 0 otherwise (for example, when a slave
has lagged too far behind the master).

A typical example for the use of this attribute would be to tie
a set of IP addresses to MySQL slaves that can be read from.

This parameter is only meaningful in master/slave set configurations.
</longdesc>
<shortdesc lang="en">Sets the node attribute that determines
whether a node is usable for clients to read from.</shortdesc>
<content type="string" default="${OCF_RESKEY_reader_attribute_default}" />
</parameter>
</parameters>

<actions>
<action name="start" timeout="120s" />
<action name="stop" timeout="120s" />
<action name="status" timeout="60s" />
<action name="monitor" depth="0" timeout="30s" interval="20s" />
<action name="monitor" role="Promoted" depth="0" timeout="30s" interval="10s" />
<action name="promote" timeout="120s" />
<action name="demote" timeout="120s" />
<action name="notify" timeout="90s" />
<action name="validate-all" timeout="5s" />
<action name="meta-data" timeout="5s" />
</actions>
</resource-agent>
END
}

# Convenience functions

set_read_only() {
    # Sets or unsets read-only mode. Accepts one boolean as its
    # optional argument. If invoked without any arguments, defaults to
    # enabling read only mode. Should only be set in master/slave
    # setups.
    # Returns $OCF_SUCCESS if the operation succeeds, or
    # $OCF_ERR_GENERIC if it fails.
    local ro_val
    if ocf_is_true $1; then
        ro_val="on"
    else
        ro_val="off"
    fi
    ocf_run $MYSQL $MYSQL_OPTIONS_REPL \
        -e "SET GLOBAL read_only=${ro_val}"
}

get_read_only() {
    # Check if read-only is set
    local read_only_state

    read_only_state=`$MYSQL $MYSQL_OPTIONS_REPL \
        --skip-column-names -e "SHOW VARIABLES LIKE 'read_only'" | awk '{print $2}'`

    if [ "$read_only_state" = "ON" ]; then
        return 0
    else
        return 1
    fi
}

is_slave() {
    # Determine whether the machine is currently running as a MySQL
    # slave, as determined per SHOW SLAVE STATUS. Returns 1 if SHOW
    # SLAVE STATUS creates an empty result set, 0 otherwise.
    local rc
    local tmpfile

    # Check whether this machine should be slave
    if ! ocf_is_ms || ! get_read_only; then
        return 1
    fi

    get_slave_info
    rc=$?
    rm -f $tmpfile

    if [ $rc -eq 0 ]; then
       # show slave status is not empty
       # Is there a master_log_file defined?  (master_log_file is deleted
       # by reset slave
       if [ "$master_log_file" ]; then
          return 0
       else
          return 1
       fi
    else
       # "SHOW SLAVE STATUS" returns an empty set if instance is not a
       # replication slave
       return 1
    fi

}

parse_slave_info() {
    # Extracts field $1 from result of "SHOW SLAVE STATUS\G" from file $2
    sed -ne "s/^.* $1: \(.*\)$/\1/p" < $2
}

get_slave_info() {
    # Warning: this sets $tmpfile and LEAVE this file! You must delete it after use!
    local mysql_options

    if [ "$master_log_file" -a "$master_host" ]; then
        # variables are already defined, get_slave_info has been run before
        return $OCF_SUCCESS
    else
        tmpfile=`mktemp ${HA_RSCTMP}/check_slave.${OCF_RESOURCE_INSTANCE}.XXXXXX`

        $MYSQL $MYSQL_OPTIONS_REPL \
        -e 'SHOW SLAVE STATUS\G' > $tmpfile

        if [ -s $tmpfile ]; then
            master_host=`parse_slave_info Master_Host $tmpfile`
            master_user=`parse_slave_info Master_User $tmpfile`
            master_port=`parse_slave_info Master_Port $tmpfile`
            master_log_file=`parse_slave_info Master_Log_File $tmpfile`
            master_log_pos=`parse_slave_info Read_Master_Log_Pos $tmpfile`
            slave_sql=`parse_slave_info Slave_SQL_Running $tmpfile`
            slave_io=`parse_slave_info Slave_IO_Running $tmpfile`
            last_errno=`parse_slave_info Last_Errno $tmpfile`
            secs_behind=`parse_slave_info Seconds_Behind_Master $tmpfile`
            ocf_log debug "MySQL instance running as a replication slave"
        else
            # Instance produced an empty "SHOW SLAVE STATUS" output --
            # instance is not a slave
            ocf_exit_reason "check_slave invoked on an instance that is not a replication slave."
            return $OCF_ERR_GENERIC
        fi

        return $OCF_SUCCESS
    fi
}

check_slave() {
    # Checks slave status
    local rc new_master

    get_slave_info
    rc=$?

    if [ $rc -eq 0 ]; then
        # Did we receive an                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         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