#!/bin/bash

# 환경변수 설정
if [ -z "${KEEPALIVED_ROUTER_ID}" ] || [ -z "${KEEPALIVED_UNICAST_PEERS}" ] || [ -z "${KEEPALIVED_VIRTUAL_IPS}" ]; then
    echo "Error: Variables 'KEEPALIVED_ROUTER_ID' or 'KEEPALIVED_UNICAST_PEERS' or 'KEEPALIVED_VIRTUAL_IPS' is not specified!"
    exit 1
fi

if [ -z "${KEEPALIVED_STATE}" ]; then
    export KEEPALIVED_STATE="BACKUP"
fi
if [ -z "${KEEPALIVED_PRIORITY}" ] && [ "${KEEPALIVED_STATE^^}" == "BACKUP" ]; then
    export KEEPALIVED_PRIORITY="$(($RANDOM%199))"
fi
if [ -z "${KEEPALIVED_PRIORITY}" ] && [ "${KEEPALIVED_STATE^^}" == "MASTER" ]; then
    export KEEPALIVED_PRIORITY="200"
fi
if [ -z "${KEEPALIVED_INTERFACE}" ]; then
    export KEEPALIVED_INTERFACE="eth0"
fi
if [ -z "${KEEPALIVED_PASSWORD}" ]; then
    export KEEPALIVED_PASSWORD="P@ssw0rd"
fi

# 구성 파일 설정
cp -f /etc/keepalived/keepalived.tmpl /etc/keepalived/keepalived.conf
chmod 644 /etc/keepalived/keepalived.conf
chown root:root /etc/keepalived/keepalived.conf

sed -i "s/_routerid_/${KEEPALIVED_ROUTER_ID}/g" /etc/keepalived/keepalived.conf && \
sed -i "s/_state_/${KEEPALIVED_STATE}/g" /etc/keepalived/keepalived.conf && \
sed -i "s/_priority_/${KEEPALIVED_PRIORITY}/g" /etc/keepalived/keepalived.conf && \
sed -i "s/_interface_/${KEEPALIVED_INTERFACE}/g" /etc/keepalived/keepalived.conf && \
sed -i "s/_password_/${KEEPALIVED_PASSWORD}/g" /etc/keepalived/keepalived.conf && \

num=`echo ${KEEPALIVED_UNICAST_PEERS} | sed 's/,/\n/g' | wc -l`
for n in $(seq ${num}); do
    ip=$(echo ${KEEPALIVED_UNICAST_PEERS} | sed 's/,/\n/g' | sed -n ${n}p)
    sed -i "/unicast_peer/a $(echo -e ${ip})" /etc/keepalived/keepalived.conf
done

num=`echo ${KEEPALIVED_VIRTUAL_IPS} | sed 's/,/\n/g' | wc -l`
for n in $(seq ${num}); do
    ip=$(echo ${KEEPALIVED_VIRTUAL_IPS} | sed 's/,/\n/g' | sed -n ${n}p)
    sed -i "/virtual_ipaddress/a ${ip}" /etc/keepalived/keepalived.conf
done

# keepalive 시작
rm -rf /var/run/keepalived
if (pgrep -fl keepalived >/dev/null 2>&1); then
    echo "Info: keepalived process already running, killing..."
    pkill -9 keepalived
fi
keepalived --use-file /etc/keepalived/keepalived.conf --dont-fork --log-console &

sleep 1
echo "Info: keepalived process started!"

# TRAP 처리
trap "stop; exit 0;" SIGHUP SIGINT SIGQUIT SIGKILL SIGTERM
stop() {
    echo "Info: killing keepalived process..."
    pkill -2 keepalived
    exit 0
}

# 동작확인
while (pgrep -fl keepalived >/dev/null 2>&1)
do
    sleep 5
done
echo "Error: keepalived is not running, exiting..."
exit 1