#!/bin/bash
#set -x
if [ `pgrep ssh-agent | wc -l` -lt 1 ]
then
    echo "**    You might do well to start ssh-agent now, bye."
    exit 1
fi

# skipping passwords for demo
# MYSLAVE="mysql -u root -p$1"

MYSLAVE="mysql -u root "
MASTER="my01"
MYMASTER="mysql -h $MASTER -P3306 -u root "
SSHMASTER="ssh root@$MASTER"

echo "**    Creating remote snap dir..."
$SSHMASTER "[ ! -d /tmp/mysql ] && mkdir /tmp/myql"
$SSHMASTER "rsync -arv /var/lib/mysql/ /tmp/mysql/"

echo "**    Stopping $MASTER database..."
$SSHMASTER "/etc/init.d/mysql stop"
sleep 10s

echo "**    Stopping SLAVE database"
echo "stop slave;" | $MYSLAVE
/etc/init.d/mysql stop

# this is a good time to block access to local and remote databases
# by manipulating ethernet interfaces or firewall rules
# We don't want to block access before we shutdown the database because
# that would possibly corrupt active connections

# example $SSHMASTER ifdown eth1

echo "**    Updating master snapshot ..."
$SSHMASTER "rsync -arv /var/lib/mysql/ /tmp/mysql/"

# consider that if the master ahead of us is also a replicant
# we want to start it up "not replicating."
# $SSHMASTER "rm -f /etc/my.cnf ; ln -s /etc/my.cnf.notslave /etc/my.cnf"

echo "**    Starting up master and capturing log position..."
$SSHMASTER "/etc/init.d/mysql start"
echo "FLUSH TABLES WITH READ LOCK;" | $MYMASTER

masterStats=$( echo "SHOW MASTER STATUS \\G" \
                | $MYMASTER )
masterBinLog=$( echo "$masterStats" \
                | awk '/File/ {print $2}' )
masterBinLogPos=$( echo "$masterStats" \
                | awk '/Position/ {print $2}' )
echo "**    Master log position f:$masterBinLog p:$masterBinLogPos"

echo "**    Unlocking $master tables..."
echo "UNLOCK TABLES;" | $MYMASTER

                                # $SSHMASTER "ifup eth1"
                                # $SSHMASTER "rm -f /etc/my.cnf ;\
                                #      ln -s /etc/my.cnf.slave /etc/my.cnf"

sleep 5s

echo "**    Rsyncing snapshot..."
/root/bin/rsyncFromMaster.sh /tmp/mysql/

echo "**    Starting local database unslaved..."
rm /etc/my.cnf
ln -s /etc/my.cnf.not-slave /etc/my.cnf
/etc/init.d/mysql start
sleep 2s

echo "**    Updating master statement..."
echo "CHANGE MASTER TO MASTER_HOST='$MASTER', \
    MASTER_USER='repoman', \
    MASTER_PASSWORD='foo', \
    MASTER_LOG_FILE='$masterBinLog', \
    MASTER_LOG_POS=$masterBinLogPos;"
echo "CHANGE MASTER TO MASTER_HOST='$MASTER', \
    MASTER_USER='repoman', \
    MASTER_PASSWORD='foo', \
    MASTER_LOG_FILE='$masterBinLog', \
    MASTER_LOG_POS=$masterBinLogPos;" \
    | $MYSLAVE

echo "**    Initiating replication..."
echo "START SLAVE;" | $MYSLAVE
                                            # echo "START SLAVE;" | $MYMASTER
                                            # ifup eth1
mv /etc/mysql/my.cnf /tmp/my.cnf.$$ 
ln -s /etc/mysql/my.cnf.slave /etc/mysql/my.cnf

# eof