实现要点

1. 需要安装keepalived和nginx，不需要haproxy
2. keepalived实现两个功能，一是浮动ip，二是nginx的高可用
3. nginx实现zuul的负载均衡
4. keepalived和nginx必须安装在同一台机器
5. keepalived的启动必须用root，而nginx的高可用是通过keepalived，所以keepalived和nginx都用root安装和启动快一点
6. 至少两台机器安装keepalived和nginx并启动着，但同一个时间使用的是其中一台，当这台挂了，才会使用另一台，感觉可能两台就够了，不需要三台以上
7. 浮动ip需要选择同一个网段的、还没使用的随便一个ip就可以

总述

21机器是vip，18、19两台机器主备。

测试

1. 访问
2. 停掉18的nginx，几秒后自动启动，18的keepalived自动启动nginx成功
3. 停掉18的keepalived，访问

keepalived和nginx的经验少，后续继续分享。

keepalived配置

18keepalived配置

[root[@test](https://my.oschina.net/azibug) keepalived]# more keepalived.conf! Configuration File for keepalivedglobal_defs {   router_id test1}vrrp_script chk_nginx {    script "/etc/keepalived/check_nginx_pid.sh"    interval 5    weight 2}vrrp_instance VI_1 {    state MASTER    interface eth0    virtual_router_id 51    priority 110    nopreempt    advert_int 1    authentication {        auth_type PASS        auth_pass 1111    }    virtual_ipaddress {        1.13.22.21    }    track_script {        chk_nginx    }}[root[@test](https://my.oschina.net/azibug) keepalived]#

19keepalived配置

与18基本一样，除了:

1. router_id要改为本机名
2. state要改为BACKUP

[root[@test2](https://my.oschina.net/u/1253032) keepalived]# more keepalived.conf! Configuration File for keepalivedglobal_defs {   router_id test2}vrrp_script chk_nginx {    script "/etc/keepalived/check_nginx_pid.sh"    interval 5    weight 2}vrrp_instance VI_1 {    state BACKUP    interface eth0    virtual_router_id 51    priority 100    nopreempt    advert_int 1    authentication {        auth_type PASS        auth_pass 1111    }    track_script {        chk_nginx    }    virtual_ipaddress {        1.13.22.21    }    }

nginx配置

18nginx配置

[root[@test](https://my.oschina.net/azibug) nginx]# more nginx.confuser  nginx;worker_processes  1;error_log  /var/log/nginx/error.log warn;pid        /var/run/nginx.pid;events {    worker_connections  1024;}http {    include       /etc/nginx/mime.types;    default_type  application/octet-stream;    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '                      '$status $body_bytes_sent "$http_referer" '                      '"$http_user_agent" "$http_x_forwarded_for"';    access_log  /var/log/nginx/access.log  main;    sendfile        on;    #tcp_nopush     on;    keepalive_timeout  65;    #gzip  on;    upstream upstream_nginx_zuul {        server 1.13.22.18:8181;        server 1.13.22.19:8181;    }    server {        listen 80;        location / {           proxy_set_header Host $host:$server_port;           proxy_pass http://upstream_nginx_zuul;        }    }    include /etc/nginx/conf.d/*.conf;}[root@test1 nginx]#

19nginx配置

和18配置完全一样。

[root@test nginx]# more nginx.confuser  nginx;worker_processes  1;error_log  /var/log/nginx/error.log warn;pid        /var/run/nginx.pid;events {    worker_connections  1024;}http {    include       /etc/nginx/mime.types;    default_type  application/octet-stream;    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '                      '$status $body_bytes_sent "$http_referer" '                      '"$http_user_agent" "$http_x_forwarded_for"';    access_log  /var/log/nginx/access.log  main;    sendfile        on;    #tcp_nopush     on;    keepalive_timeout  65;    #gzip  on;    upstream upstream_nginx_zuul {        server 1.13.22.18:8181;        server 1.13.22.19:8181;    }    server {        listen 80;        location / {           proxy_set_header Host $host:$server_port;           proxy_pass http://upstream_nginx_zuul;        }    }    include /etc/nginx/conf.d/*.conf;}

高可用检查脚本

两台机器一样。

[root@test2 keepalived]# more check_nginx_pid.sh #!/bin/bashLOG_DIR="/etc/keepalived"  echo $(date "+%Y-%m-%d %H:%M:%S") "check nginx status" >> $LOG_DIR/log_nginx.log A=`ps -C nginx --no-header |wc -l`        if [ $A -eq 0 ];then                                  /usr/sbin/nginx                #重启nginx      echo  $(date "+%Y-%m-%d %H:%M:%S") "restarting nginx..." >> $LOG_DIR/restart.log      sleep 2      if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then    #nginx重启失败，则停掉keepalived服务，进行VIP转移              #killall keepalived                                  echo $(date "+%Y-%m-%d %H:%M:%S") "killing keepalived..." >> $LOG_DIR/restart.log      fifi