#什么是jinja2模板
jinja2是Python的全功能模板引擎---------- >就是一个配置文件模块，支持变量。
#Jinja2与Ansible啥关系
Ansible通常会使用jinja2模板来修改被管理主机的配置文件等...在saltstack中同样会使用到jinja2
如果在100台主机上安装redis，每台redis的监听地址都不一样，如何解决？
#Ansible如何使用Jinja2
使用Ansible的jinja2模板也就是使用template模块，该模块和copy模块一样，都是将文件复制到远端主机上去，但是区别在于，template模块可以获取到文件中的变量，而copy则是原封不动的把文件内容复制过去。之前我们在推送rsync的backup脚本时，想把脚本中的变量名改成主机名，如果使用copy模块则推送过去的就是{{ ansible_fqdn }}，不变，如果使用template，则会变成对应的主机名。
#Ansible使用Jinja2注意事项
Ansible允许jinja2模板中使用条件判断和循环，但是不允许在playbook中使用。
注意：不是每个管理员都需要这个特性，但是有些时候jinja2模块能大大提高效率。
# jijia2 模板语言
通常情况下是放在模块文件中的一个标记性语言。
# 语言
1、变量
2、循环
3、变量的数据类型
# ---
一个剧本只能有一个 ---
切记，切记
模板是一个文本文件，可以做为生成文件的模版，并且模板文件中还可嵌套jinja语法。
官方网站：
http://jinja.pocoo.org/
https://jinja.palletsprojects.com/en/2.11.x/
- 字符串：使用单引号或双引号,
- 数字：整数，浮点数
- 列表：[item1, item2, ...]
- 元组：(item1, item2, ...)
- 字典：{key1:value1, key2:value2, ...}
- 布尔型：true/false
- 算术运算：+, -, *, /, //, %, **
- 比较操作：==, !=, >, >=, <, <=
- 逻辑运算：and，or，not
- 流表达式：For，If，When
template功能：可以根据和参考模块文件，动态生成相类似的配置文件，template文件必须存放于templates目录下，且命名为 .j2 结尾，yaml/yml 文件需和templates目录平级，目录结构如下示例：
./
├── temnginx.yml
└── templates
└── nginx.conf.j2
#准备templates/nginx.conf.j2文件
[root@ansible ~]#vim temnginx.yml
---
- hosts: web
remote_user: root
tasks:
- name: template config to remote hosts
template: src=nginx.conf.j2 dest=/etc/nginx/nginx.conf
[root@ansible ~]#ansible-playbook temnginx.yml
#修改文件nginx.conf.j2
[root@ansible ~]#mkdir templates
[root@ansible ~]#vim templates/nginx.conf.j2
......
worker_processes {{ ansible_processor_vcpus }};
# worker_processes {{ ansible_processor_vcpus % }}; #全部自动获取cpu核心数
......
[root@ansible ~]#vim temnginx2.yml
---
- hosts: web_group
remote_user: root
tasks:
- name: install nginx
yum: name=nginx
- name: template config to remote hosts
template: src=nginx.conf.j2 dest=/etc/nginx/nginx.conf
- name: start service
service: name=nginx state=started enabled=yes
[root@ansible ~]#ansible-playbook temnginx2.yml
[root@ansible ansible]#vim templates/nginx.conf.j2
# worker_processes {{ ansible_processor_vcpus**3 }}; #运算* 的三次方
# worker_processes {{ ansible_processor_vcpus*3 }}; #运算 * 3
[root@ansible ansible]#cat templnginx.yml
---
- hosts: web_group
remote_user: root
tasks:
- name: install nginx
yum: name=nginx
- name: template config to remote hosts
template: src=nginx.conf.j2 dest=/etc/nginx/nginx.conf
notify: restart nginx
- name: start service
service: name=nginx state=started enabled=yes
handlers:
- name: restart nginx
service: name=nginx state=restarted
[root@ansible ~]#-playbook templnginx.yml --limit 10.0.0.8
template中也可以使用流程控制 for 循环和 if 条件判断，实现动态生成文件功能
# 需求：在web机器中搭建三个项目，分别使用80、81、82三个端口
#temlnginx2.yml
---
- hosts: websrvs
remote_user: root
vars:
nginx_vhosts:
- 81
- 82
- 83
tasks:
- name: template config
template: src=nginx.conf2.j2 dest=/data/nginx.conf
#templates/nginx.conf2.j2
{% for vhost in nginx_vhosts %}
server {
listen {{ vhost }}
}
{% endfor %}
ansible-playbook -C templnginx2.yml --limit 192.168.15.8
#生成的结果：
server {
listen 81
}
server {
listen 82
}
server {
listen 83
}
# 需求：部署www.abck8s.com、blog.abck8s.com、linux.abck8s.com
#templnginx4.yml
- hosts: websrvs
remote_user: root
vars:
nginx_vhosts:
- listen: 8080
server_name: "web1.oldboy.com"
root: "/var/www/nginx/web1/"
- listen: 8081
server_name: "web2.oldboy.com"
root: "/var/www/nginx/web2/"
- listen: 8082
server_name: "web3.oldboy.com"
root: "/var/www/nginx/web3/"
tasks:
- name: template config
template: src=nginx.conf4.j2 dest=/data/nginx4.conf
# templates/nginx.conf4.j2
{% for vhost in nginx_vhosts %}
server {
listen {{ vhost.listen }}
server_name {{ vhost.server_name }}
root {{ vhost.root }}
}{% endfor %}
[root@ansible ~]#ansible-playbook templnginx4.yml --limit 10.0.0.8
#生成结果：
server {
listen 8080
server_name web1.oldboy.com
root /var/www/nginx/web1/
}
server {
listen 8081
server_name web2.oldboy.com
root /var/www/nginx/web2/
}
server {
listen 8082
server_name web3.oldboy.com
root /var/www/nginx/web3/
}
when语句，可以实现条件测试。如果需要根据变量、facts或此前任务的执行结果来做为某task执行与否的前提时要用到条件测试,通过在task后添加when子句即可使用条件测试，jinja2的语法格式。
tasks:
- name: "shut down CentOS 6 and Debian 7 systems"
command: /sbin/shutdown -t now
when: (ansible_facts['distribution'] == "CentOS" and ansible_facts['distribution_major_version'] == "6") or (ansible_facts['distribution'] == "Debian" and ansible_facts['distribution_major_version'] == "7")
迭代：当有需要重复性执行的任务时，可以使用迭代机制对迭代项的引用，固定内置变量名为"item"，要在task中使用with_items给定要迭代的元素列表
注意: ansible2.5版本后,可以用loop代替with_items
---
- hosts: websrvs
remote_user: root
tasks:
- name: add several users
user: name={{ item }} state=present groups=wheel
with_items:
- testuser1
- testuser2
- testuser3
#上面语句的功能等同于下面的语句
- name: add several users
user: name=testuser1 state=present groups=wheel
- name: add several users
user: name=testuser2 state=present groups=wheel
- name: add several users
user: name=testuser3 state=present groups=wheel
---
#remove mariadb server
- hosts: 172.16.1.7
remote_user: root
tasks:
- name: stop service
shell: /etc/init.d/mysqld stop
- name: delete files and dir
file: path="{{item}}" state=absent
with_items:
- /usr/local/mysql
- /usr/local/mariadb-10.2.27-linux-x86_64
- /etc/init.d/mysqld
- /etc/profile.d/mysql.sh
- /etc/my.cnf
- /data/mysql
- name: delete user
user: name=mysql state=absent remove=yes
---
- hosts: websrvs
remote_user: root
tasks:
- name: add some groups
group: name="{{ item }}" state=present
with_items:
- nginx
- mysql
- apache
- name: add some users
user: name="{{ item.name }}" group="{{ item.group }} "state=present
with_items:
- { name: 'nginx', group: 'nginx' }
- { name: 'mysql', group: 'mysql' }
- { name: 'apache', group: 'apache' }
管理节点过多导致的超时问题解决方法 默认情况下，Ansible将尝试并行管理playbook中所有的机器。对于滚动更新用例，可以使用serial关键字定义Ansible一次应管理多少主机，还可以将serial关键字指定为百分比，表示每次并行执行的主机数占总数的比例
#vim test_serial.yml
---
- hosts: all
serial: 2 #每次只同时处理2个主机,将所有task执行完成后,再选下2个主机再执行所有task,直至所有主机
gather_facts: False
tasks:
- name: task one
comand: hostname
- name: task two
command: hostname
# 案例2：
- name: test serail
hosts: all
serial: "20%" #每次只同时处理20%的主机
#修改文件nginx.conf.j2
[root@ansible ~]#mkdir templates
[root@ansible ~]#vim templates/nginx.conf.j2
......
worker_processes {{ ansible_processor_vcpus }};
......
[root@ansible ~]#vim temnginx2.yml
---
- hosts: web
remote_user: root
tasks:
- name: install nginx
yum: name=nginx
- name: template config to remote hosts
template: src=nginx.conf.j2 dest=/etc/nginx/nginx.conf
- name: start service
service: name=nginx state=started enabled=yes
[root@ansible ~]#ansible-playbook temnginx2.yml
{{ EXPR }} 输出变量值，会输出自定义的变量值或facts
1.playbook文件使用template模块
2.模板文件里面变量使用 {{ 名称 }}，比如 {{ PORT }} 或使用facts
#shell中的判断语法
[root@m01 ~]# vim pd.sh
#!/bin/
age=$1
if [ $age -lt 18 ];then
echo "小姐姐"
else
echo "大妈"
fi
#Jinja2模板判断语法
#条件判断
{% if EXPR %}
{% elif EXPR %}
{% else %}
{% endif %}
#shell中的循环
[root@m01 ~]# vim xh.sh
#!/bin/
for i in `seq 10`
do
echo $i
done
#Jinja2模板循环语法
#循环表达式
{% for i in EXPR %}
{% endfor %}
#shell中的注释
使用 # 写在注释内容最前面
#Jinja2模板注释语法
{# COMMENT #}
1、配置登陆文件的 jinja2 模板
[root@m01 ~]# vim motd.j2
Welcome to {{ ansible_fqdn }}
This system total mem is : {{ ansible_memtotal_mb }} MB
This system free mem is: {{ ansible_memfree_mb }} MB
2、编写剧本
[root@m01 ~]# vim motd.yml
- hosts: all
tasks:
- name: Config motd
template:
src: ./motd.j2
dest: /etc/motd
3、执行并查看结果
[root@m01 ~]# ansible-playbook motd.yml
#查看结果
Connecting to 10.0.0.51:22...
Connection established.
To escape to local shell, press 'Ctrl+Alt+]'.
Last login: Thu Dec 24 15:29:37 2020 from 10.0.0.61
Welcome to db01
This system total mem is : 972 MB
This system free mem is: 267 MB
[root@db01 ~]#
1、配置数据库配置文件
[root@m01 ~]# vim /etc/my.cnf
innodb_buffer_pool_size = {{ ansible_memtotal_mb * 0.8 }}M
2、编写剧本
[root@m01 ~]# cat my.yml
- hosts: db01
tasks:
- name: Config Mariadb
template:
src: /etc/my.cnf
dest: /etc/
3、执行并查看
[root@m01 ~]# ansible-playbook my.yml
#检查
[root@db01 ~]# vim /etc/my.cnf
[mysqld]
innodb_buffer_pool_size = 777.6M
4、jinja2模板修改
[root@m01 ~]# vim /etc/my.cnf
...
[mysqld]
{% if ansible_memtotal_mb == 972 %}
innodb_buffer_pool_size = 800M
{% elif ansible_memtotal_mb == 1980 %}
innodb_buffer_pool_size = 1600M
{% endif %}
...
5、再次执行查看
#查看服务器
1.如果服务器内存是 972M，则配置为 innodb_buffer_pool_size = 800M
2.如果服务器内存是 1980M，则配置为 innodb_buffer_pool_size = 1600M
#1.正常的配置文件
[root@m01 ~]# vim conf/upstream.conf
upstream web {
server 172.16.1.7;
server 172.16.1.8;
}
server {
listen 80;
server_name linux.wp.com;
location / {
proxy_pass http://web;
proxy_set_header Host $http_host;
}
}
#2.不正经的配置文件
[root@m01 ~]# vim conf/upstream.j2 # 方式一
upstream {{ server_name }} {
{% for i in range(7,20) %}
server {{ net_ip }}.{{ i }};
{% endfor %}
}
server {
listen {{ web_port }};
server_name {{ server_name }};
location / {
proxy_pass http://{{ server_name }};
proxy_set_header Host $http_host;
}
}
[root@m01 conf]# cat upstream.j2.conf # 方式二
upstream {{ server_name }} {
{% for i in range(7,20) %}
server {{ net_ip }}.{{ i }};
{% endfor %}
}
server {
listen {{ web_port }};
server_name {{ server_name }};
location / {
proxy_pass http://{{ server_name }};
proxy_set_header Host $http_host;
}
}
[root@m01 ~]# vim upstream_vars.yml # 方式一
server_name: linux.wp.com
web_port: 80
net_ip: 172.16.1
[root@m01 conf]# cat upstream.vars.yml #方式二
server_name: linux12.wp.com
web_port: 80
net_ip: 172.16.1
[root@m01 ~]# vim lb.yml #方式一
- hosts: lb_server
vars_files: ./upstream_vars.yml
tasks:
- name: Config Nginx Upstream
template:
src: conf/upstream.j2
dest: /etc/nginx/conf.d/upstream.conf
notify: restert_up stream
- name: Start Nginx Server
systemd:
name: nginx
state: started
handlers:
- name: restert_upstream
systemd:
name: nginx
state: restarted
[root@m01 conf]# cat lb.yml # 方式二
- hosts: lb01
vars_files: /mm/conf/upstream.vars.yml
tasks:
- name: config slb
template:
src: /mm/conf/upstream.j2.conf
dest: /etc/nginx/conf.d/upstream.conf
- name: restart slb nginx
systemd:
name: nginx
state: restarted
[root@m01 ~]# ansible-playbook lb.yml
[root@m01 ~]# yum -y install keepalived
#1.正经的配置文件
[root@m01 ~]# vim conf/keepalived.conf
global_defs {
router_id lb02
}
vrrp_instance VI_1 {
state BACKUP # state MASTER（抢占式 主节点）
nopreempt #删除 nopreempt
interface eth0
virtual_router_id 50
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.15.102
}
}
#2.不正经的配置文件
[root@m01 conf]# cat keepalived.j2
global_defs {
router_id {{ ansible_fqdn }}
}
vrrp_instance VI_1 {
{% if ansible_fqdn == "lb01" %}
state MASTER
priority 100
# state BACKUP
# priority 100
# nopreempt
{% else %}
state BACKUP
priority 90
nopreempt
{% endif %}
interface eth0
virtual_router_id 50
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.15.102
}
}
# 3.keepalived调用文件
[root@m01 conf]# vim upstream.vars.yml
server_name: linux12.wp.com
web_port: 80
net_ip: 172.16.1
[root@m01 conf]# cat keepalived.yml
- hosts: slb
vars_files: /mm/conf/upstream.vars.yml
tasks:
- name: Install keepalived Server
yum:
name: keepalived
state: present
- name: Config keepalived Server
template:
src: /mm/conf/keepalived.j2
dest: /etc/keepalived/keepalived.conf
- name: Start keepalived Server
systemd:
name: keepalived
state: restarted
enabled: yes
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