[root@localhost ~]# ping 172.18.0.15

PING 172.18.0.15 (172.18.0.15) () bytes of data.

From 172.18.0.1 icmp_seq= Destination Host Unreachable

From 172.18.0.1 icmp_seq= Destination Host Unreachable

From 172.18.0.1 icmp_seq= Destination Host Unreachable

From 172.18.0.1 icmp_seq= Destination Host Unreachable

From 172.18.0.1 icmp_seq= Destination Host Unreachable

From 172.18.0.1 icmp_seq= Destination Host Unreachable

进入到docker服务内，不是在宿主机上哦，查看配置文件

root@8351443065ea:/etc/keepalived# cat keepalived.conf

vrrp_instance  VI_1 {

    state  MASTER

    interface  eth0

    virtual_router_id

    priority

    advert_int

    authentication {

        auth_type  PASS

        auth_pass

    }

    virtual_ipaddress {

        172.18.0.201

    }

}

如果配置文件信息都是正确的，通过ip a命令会显示如当前docker服务有的网卡

root@ec688a676a07:/# ip a

: lo: <LOOPBACK,UP,LOWER_UP> mtu  qdisc noqueue state UNKNOWN group default qlen

    link/loopback ::::: brd :::::

    inet 127.0.0.1/ scope host lo

       valid_lft forever preferred_lft forever

    inet6 ::/ scope host

       valid_lft forever preferred_lft forever

: eth0@if18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu  qdisc noqueue state UP group default ;

很明显没有我配置文件中的172.18.0.201ip地址，代表配置文件未生效，大多数配置文件错误

停掉keepalived服务重新修改编辑后重启

root@ec688a676a07:/# service keepalived stop

[....] Stopping keepalived: keepalived. ok

重启服务

root@ec688a676a07:/# service keepalived start

[....] Starting keepalived: keepalived. ok 

再次查看docker服务的ip

root@ec688a676a07:/# ip a

: lo: <LOOPBACK,UP,LOWER_UP> mtu  qdisc noqueue state UNKNOWN group default qlen

    link/loopback ::::: brd :::::

    inet 127.0.0.1/ scope host lo

       valid_lft forever preferred_lft forever

    inet6 ::/ scope host

       valid_lft forever preferred_lft forever

: eth0@if18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu  qdisc noqueue state UP group default

    link/ether ::ac::: brd ff:ff:ff:ff:ff:ff link-netnsid

    inet 172.18.0.7/ scope global eth0

       valid_lft forever preferred_lft forever

这里出现了我的配置文件ip地址

    inet 172.18.0.201/ scope global eth0

       valid_lft forever preferred_lft forever

    inet6 fe80:::acff:fe12:/ scope link

       valid_lft forever preferred_lft forever

在服务内直接ping这个ip，发现能ping通，切换宿主机，也能ping通，解决问题

[root@localhost ~]# ping 172.18.0.201

PING 172.18.0.201 (172.18.0.201) () bytes of data.

 bytes from 172.18.0.201: icmp_seq= ttl= time=0.077 ms

 bytes from 172.18.0.201: icmp_seq= ttl= time=0.064 ms