keepalived

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طريقة الكتابة

keepalived [-f FILE] [-t] [-D] [-n]
systemctl {start|reload|status} keepalived

الأجزاء الرئيسية

Config parts

global_defs

Router ID, script security.

vrrp_script NAME { script … interval … }

Health check.

vrrp_instance NAME { … }

One VIP group.

state MASTER|BACKUP

Start role.

priority N

Higher wins (100 master, 90 backup).

virtual_router_id N

Same on all nodes of one group (1–255).

virtual_ipaddress { … }

The VIP(s).

authentication / unicast_peer

Simple auth / unicast instead of multicast.

track_script { NAME }

Lower priority when the check fails.

الأكثر استخدامًا

لا يوجد شيء يطابق هذا الفلتر.

$ مستخدم عادي# بصلاحية root (أو مع sudo)

1. 1Install on both nodes

   #dnf install -y keepalived haproxy

2. 2Master node config

   #cat /etc/keepalived/keepalived.conf
   global_defs {
       router_id lb1
       enable_script_security
       script_user root
   }
   vrrp_script chk_haproxy {
       script "/usr/bin/systemctl is-active --quiet haproxy"
       interval 2
       fall 2
       rise 2
   }
   vrrp_instance VI_1 {
       state MASTER
       interface eth0
       virtual_router_id 51
       priority 100
       advert_int 1
       unicast_src_ip 192.168.122.21
       unicast_peer { 192.168.122.22 }
       virtual_ipaddress { 192.168.122.20/24 }
       track_script { chk_haproxy }
   }

3. 3Backup node: same file with these changes

   #grep -E "router_id|state|priority|unicast" /etc/keepalived/keepalived.conf
       router_id lb2
       state BACKUP
       priority 90
       unicast_src_ip 192.168.122.22
       unicast_peer { 192.168.122.21 }

4. 4Allow VRRP in the firewall

   #firewall-cmd --permanent --add-rich-rule='rule protocol value="vrrp" accept' && firewall-cmd --reload

5. 5Check and start

   #keepalived -t -f /etc/keepalived/keepalived.conf
   #systemctl enable --now keepalived

6. 6Who has the VIP?

   #ip -br addr show eth0
   eth0  UP  192.168.122.21/24 192.168.122.20/24

7. 7Test a failover

   #systemctl stop haproxy
   #journalctl -u keepalived -n 5
   #ip -br addr show eth0

8. 8Watch VRRP traffic

   #tcpdump -ni eth0 vrrp

9. 9Allow binding to the VIP on the backup (HAProxy)

   #sysctl -w net.ipv4.ip_nonlocal_bind=1
   #echo "net.ipv4.ip_nonlocal_bind = 1" > /etc/sysctl.d/90-vip.conf

10. 10Read the state changes

    #journalctl -u keepalived | grep -E "MASTER|BACKUP|FAULT"

لا يوجد شيء يطابق هذا الفلتر.

الملفات

/etc/keepalived/keepalived.conf

Configuration.

رموز الخروج