一、使用jinja2管理Keepalived配置文件
VRRP 虚拟路由冗余协议
将多台路由器组成路由器组（Router Group），组中包括Master及Backup，在外部看来就像一台路由
器，拥有一个VIP。Master会发送组播消息，当Backup在指定的时间收不到vrrp包就会认为master宕掉，
然后通过VRRP协议再次竞选新的路由器当Master，从而保证路由器的高可用。
# vim /tmp/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id {{ ansible_hostname }}
}
vrrp_script check_nginx {
script "/etc/keepalived/check.sh"
interval 2
}
vrrp_instance VI_1 {
{% if ansible_hostname == "ansible2" %}
state MASTER
interface ens33
priority 100
{% elif ansible_hostname == "ansible3" %}
state BACKUP
interface ens33
priority 80
{% endif %}
virtual_router_id 50
advert_int 1
authentication {
auth_type PASS
auth_pass pass
}
virtual_ipaddress {
192.168.58.99/24
}
track_script {
check_nginx
}
}
存活检测
# vim check.sh
# /bin/bash
curl -l localhost &> /dev/null
if [ $? -ne 0 ];then
systemctl stop keepalived
fi
1、如果MASTER宕机了，IP会飘到BACKUP上，假设有多台BACKUP，则按照权重飘到权重最高的机子上 priority 100 priority 80 priority 60
2、如果MASTER正常运行后，IP会自动飘到MASTER的机器上 跟权重无关，权重只在多台BACKUP上有用
3、为了防止脑裂（IP不能飘到别的正常机子上），同时也避免宕机后IP飘到别的机子上服务会有几秒的暂停时间所以：
把全部的机子改为BACKUP模式，根据权重会优先飘到权重较高的机子上，但为了避免换机出现几秒的暂停时间，可以加上参数
vrrp_instance VI_1 {
state BACKUP
nopreempt //不抢占
就会一直使用本机，除非本机宕机后才会飘到其他BACKUP
二、使用jinja2管理nginx配置文件
初级：使用if判断
# vim nginx.conf
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
include /usr/share/nginx/modules/*.conf;
events {
worker_connections 1024;
}
http {
log_format main '$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;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 4096;
include /etc/nginx/mime.types;
default_type application/octet-stream;
include /etc/nginx/conf.d/*.conf;
{% if usepass == "true" %}
upstream zhangsan {
server 192.168.58.12;
server 192.168.58.10;
}
{% endif %}
server {
listen 80;
server_name _;
location / {
{% if usepass == "false" %}
root /usr/share/nginx/html;
index index.html;
{% elif usepass == "true" %}
proxy_pass http://zhangsan;
{% endif %}
}
}
}
中级：使用if判断+for循环
在原来剧本的基础上添加循环的变量
# vim jinja2.yaml
---
- hosts: web1
vars:
- iplist:
- ip: "192.168.58.10"
- ip: "192.168.58.11"
- ip: "192.168.58.12"
修改nginx配置文件，在原来upstream的基础上修改
# vim nginx.conf
{% if usepass == "true" %}
upstream ansible_nginx {
{% for server in iplist %}
server {{ server.ip }};
{% endfor %}
}
{% endif %}
# ansible-playbook jinja2.yaml -e usepass=true
高级：添加变量
第一种
# vim jinja2.yaml
---
- hosts: web1
vars:
- urilist:
- uri: "/"
passname: "ansible_nginx1"
iplist:
- 192.168.58.10
- 192.168.58.11
- 192.168.58.12
- uri: "/web"
passname: "ansible_nginx2"
iplist:
- 192.168.58.13
- 192.168.58.14
- 192.168.58.15
tasks:
nginx的配置文件
# vim nginx.conf
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
include /usr/share/nginx/modules/*.conf;
events {
worker_connections 1024;
}
http {
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;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 4096;
include /etc/nginx/mime.types;
default_type application/octet-stream;
include /etc/nginx/conf.d/*.conf;
{% if usepass == "true" %}
{% for pass in urilist %}
upstream {{ pass.passname }} {
{% for ip in pass.iplist %}
server {{ ip }};
{% endfor %}
}
{% endfor %}
{% endif %}
server {
listen 80;
server_name _;
{% if usepass == "false" %}
{% for pass in urilist %}
location {{ pass.uri }} {
root /usr/share/nginx/html;
index index.html;
}
{% endfor %}
{% endif %}
{% if usepass == "true" %}
{% for pass in urilist %}
location {{ pass.uri }} {
proxy_pass http://{{ pass.passname }};
}
{% endfor %}
{% endif %}
}
}
第二种：ip可以调用主机清单里面的主机组
# vim /etc/ansible/hosts
[web5]
192.168.58.10
192.168.58.11
192.168.58.12
[web6]
192.168.58.13
192.168.58.14
192.168.58.15
# vim jinja2.yaml
---
- hosts: web1
vars:
- urilist:
- uri: "/"
passname: "ansible_nginx1"
iplist:
- 192.168.58.10
- 192.168.58.11
- 192.168.58.12
- uri: "/web"
passname: "ansible_nginx2"
iplist:
- 192.168.58.13
- 192.168.58.14
- 192.168.58.15
tasks:
nginx的配置文件
{% for ip in pass.iplist %} 修改成 {% for ip in groups[pass.iplist] %}
部分
# vim jinja.yaml
---
- hosts: web1
vars:
- urilist:
- uri: "/"
passname: "ansible_nginx1"
iplist: web5
- uri: "/web"
passname: "ansible_nginx2"
iplist: web6
