maprangzth/vip-with-keepalived.md

## vip-with-keepalived.md

      
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              vip-with-keepalived.md
            
          
    VIP for Elasticsearch and Logstash with Keepalived


Author: Komsan Kamsamur <maprangzth@hotmail.com>
Date: 2018-01-17
Latest updated: 2018-01-17

Step 1: Install keepalived

# yum -y install keepalived
# chkconfig keepalived on

Step 2: Configure Keepalived

cat <<'EOF' > /etc/keepalived/keepalived.conf
vrrp_script chk_5142 {
    script  "</dev/tcp/127.0.0.1/5142"
    interval 30   # check every "n" seconds
    fall 2        # require 2 failures for KO
    rise 2        # require 4 successes for OK
}

vrrp_script check_9200 {
    script  "</dev/tcp/127.0.0.1/9200"
    interval 30   # check every "n" seconds
    fall 2        # require 2 failures for KO
    rise 2        # require 4 successes for OK
}

vrrp_instance VIP_LS-ES {
    state MASTER
    interface eth0
    dont_track_primary
    virtual_router_id 1
    priority 153
    advert_int 5
    mcast_src_ip 192.168.30.1
    authentication {
        auth_type PASS
        auth_pass 1111
    }

    virtual_ipaddress {
        192.168.30.59/24 dev eth0
    }

    track_script {
        chk_5142
        chk_9200
    }

    notify /etc/keepalived/notify_state
    notify_master "/etc/keepalived/vrrp_script MASTER"
    notify_backup "/etc/keepalived/vrrp_script BACKUP"
    notify_fault "/etc/keepalived/vrrp_script FAULT"

}
EOF
Step 3: Notify Script


vrrp_script: if STATE = FAULT, keepalived will stop

cat <<'EOF' > /etc/keepalived/vrrp_script 
#!/bin/bash

STATE=$1
NOW=$(date +"%Y-%m-%d %T")
KEEPALIVED="/etc/keepalived"

case $STATE in
        "MASTER") touch $KEEPALIVED/MASTER
                  echo "$NOW Becoming MASTER" >> $KEEPALIVED/COUNTER
                  exit 0
                  ;;
        "BACKUP") rm $KEEPALIVED/MASTER
                  echo "$NOW Becoming BACKUP" >> $KEEPALIVED/COUNTER
                  exit 0
                  ;;
        "FAULT")  rm $KEEPALIVED/MASTER
                  echo "$NOW Becoming FAULT" >> $KEEPALIVED/COUNTER
                  /etc/init.d/keepalived stop || killall -0 keepalived
                  exit 0
                  ;;
        *)        echo "unknown state"
                  echo "$NOW Becoming UNKOWN" >> $KEEPALIVED/COUNTER
                  exit 1
                  ;;
esac
EOF

notify script when keepalived start

cat <<'EOF' > /etc/keepalived/notify_state 
#!/bin/bash

echo $1 $2 is in $3 state > /var/run/keepalived.$1.$2.state
EOF

script get instance status

cat <<'EOF' > /etc/keepalived/getVIP_state
#!/bin/bash

cat /var/run/keepalived.*.*.state
EOF
# ln -s /etc/keepalived/getVIP_state /usr/local/bin/getVIP_state

Step 4: Allowing VIP

# echo "net.ipv4.ip_nonlocal_bind=1" >> /etc/sysctl.conf
# sysctl -p  


ref: https://everythingshouldbevirtual.com/highly-available-elk-elasticsearch-logstash-kibana-setup/

Step 5: Start Keepalived service

# service keepalived start