1.什么是变量？
以一个固定的字符串，表示一个不固定的值
2.定义变量
（1）在playbook中定义变量
①vars关键字
例题：
[root@manager project1]# cat f2.yml
- hosts: webservers
vars:
- file_name: playbook_vars
tasks:
- name: Create New File
file:
path: /tmp/{{ file_name }}
state: touch
②vars_file
QQ图片20191011194937.png
例题：
[root@manager project1]# cat vars_file.yml
web_packages: httpd
ftp_packages: vsftpd
[root@manager project1]# cat f2.yml
- hosts: webservers
vars:
- file_name: playbook_vars
#调用共享vars_file文件,只不过刚好文件名叫vars_file
vars_files: ./vars_file.yml
tasks:
- name: Create New File
file:
path: /tmp/{{ file_name }}
state: touch
- name: Installed Packages {{ web_packages }}
yum:
name: "{{ web_packages }}"
state: present
（2）在inventory主机清单中定义变量
①清单文件中直接定义(hosts文件中定义）
[webservers]
172.16.1.7
172.16.1.8
[webservers:vars]
file_name=hostsfile_group_vars
②准备hosts_vars group_vars目录
例题：
[root@manager project1]# mkdir hosts_vars #单个主机
[root@manager project1]# mkdir group_vars #主机组
#1.单个主机定义和使用方式 (host_vars能分别对不同的主机定义变量)
[root@manager project1]# cat host_vars/172.16.1.7
host_vars_name: 172.16.1.7
[root@manager project1]# cat host_vars/172.16.1.8
host_vars_name: 172.16.1.8
[root@manager project1]# cat f4.yml
- hosts: webservers
tasks:
- name: Create New File
file:
path: /opt/{{ host_vars_name }}
state: touch
#2.针对主机组定义的方式
#给指定的webserver组设定变量.其他组主机无法使用该变量
[root@manager project1]# cat group_vars/webservers
group_host_vars: webservers
[root@manager project1]# cat f5.yml
- hosts: webservers
tasks:
- name: Create New File {{ group_host_vars }}
file:
path: /opt/{{ group_host_vars }}
state: touch
#3.针对主机组定义的方式 (给所有的主机和主机组设定变量)
[root@manager project1]# cat group_vars/all
group_host_vars: all
[root@manager project1]# cat f5.yml
- hosts: webservers
tasks:
- name: Create New File {{ group_host_vars }}
file:
path: /opt/{{ group_host_vars }}
state: touch
（3）通过外置传参定义变量-e
例题：
[root@manager project1]# ansible-playbook -i hosts f6.yml -e "web_vars=123"
3.变量冲突，优先级
（1）定义相同的变量不同的值，来测试变量的优先级。
操作步骤如下：file_name
①在plabook中定义vars变量
②在playbook中定义vars_files变量
③在inventory主机定义变量
④在inventory主机组定义变量
⑤在host_vars中定义变量
⑥在group_vars中定义变量 组 all组
⑦通过执行命令传递变量
（2）优先级测试总结
外置传入参数优先级最高---->playbook(vars_files[共享]---->vars[私有])---->host_vars--->group_vars/group_name--->group_vars/all
4.变量注册
例题：
[root@manager project1]# cat f8.yml
- hosts: webservers
tasks:
# System_Status=$(netstat -lntp)
- name: Get Network Status
shell: netstat -lntp | grep "nginx"
register: System_Status
# echo "$System_Status"
- name: Debug output Variables
debug:
msg: "{{
System_Status.stdout_lines }}"
5.facts变量
ansible facts是在被管理主机上通过ansible自动采集发现的变量。facts包含每台特定的主机信息
-
facts使用的场景
Image fas.png
（1）根据主机的cpu信息，生成不同的配置
A: 1核心 work_process 1;
B: 2核心 work_process 2;
[root@manager project1]# cat f10.yml
- hosts: webservers
tasks:
- name: Configure Nginx.conf
template:
src: ./file/nginx.conf.j2
dest: /etc/nginx/nginx.conf
[root@manager project1]# cat ./file/nginx.conf.j2
user www;
worker_processes {{ ansible_processor_vcpus }};
error_log /var/log/nginx/error.log notice;
pid /var/run/nginx.pid;
events {
worker_connections {{ ansible_processor_vcpus*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;
include /etc/nginx/conf.d/*.conf;
}
[root@manager project1]#
（2）根据主机名称设定不同配置文件
zabbix_agent
Server: ===> 指向172.16.1.61
Hostname: web01 web02
[root@manager project1]# cat ./file/zabbix_agent.conf.j2
Server={{ zabbix_server_ip }}
ServerActive={{ zabbix_server_ip }}
Hostname={{ ansible_hostname }}
[root@manager project1]# cat f11.yml
- hosts: webservers
vars:
- zabbix_server_ip: 172.16.1.61
tasks:
- name: Configure zabbix-agent.conf
template:
src: ./file/zabbix_agent.conf.j2
dest: /tmp/zabbix-agent.conf
（3）3.根据主机的内存生成不同的配置文件,memcached
[root@manager project1]# cat f12.yml
- hosts: webservers
tasks:
- name: Installed Memcached Server
yum:
name: memcached
state: present
- name: Configure Memcached Server
template:
src: ./file/memcached.j2
dest: /etc/sysconfig/memcached
notify: Restart Memcached Server
- name: System Memcached Server
systemd:
name: memcached
state: started
enabled: yes
handlers:
- name: Restart Memcached Server
systemd:
name: memcached
state: restarted
[root@manager project1]# cat file/memcached.j2
PORT="11211"
USER="memcached"
MAXCONN="1024"
CACHESIZE="{{ ansible_memtotal_mb //2 }}"
OPTIONS=""
ff.png
（4）使用ansible批量修改200台主机的主机名称？（名称必须随机，没有任何规律）
[root@manager project1]# cat f13.yml
- hosts: webservers
tasks:
- name: RANDOM
shell: echo "$RANDOM"
register: System_SJ
- name: Debug
debug:
msg: "web_{{ System_SJ.stdout }}"
#1.提取facts变量中的IP地址 mac地址 UUID 等等 只要唯一
ansible_default_ipv4.address
[root@manager project1]# cat f14.yml
- hosts: webservers
tasks:
- name: Debug
debug:
msg: "web_{{ ansible_default_ipv4.address }}"
Ansible流程控制
6.判断语句
- （1）.centos和ubuntu系统都需要安装httpd, 判断系统.
- （2）.安装软件仓库,只有web组的安装webtatic其他的主机全部跳过.
- （3）.TASK任务, TASK1任务执行成功,才会执行TASK2
例题：
（1）根据不同的系统,安装不同的服务
- hosts: webservers
tasks:
- name: CentOS Installed Httpd Server
yum:
name: httpd
state: present
when: ( ansible_distribution == "CentOS" )
- name: Ubuntu Installed Httpd Server
yum:
name: httpd2
state: present
when: ( ansible_distribution == "Ubuntu" )
[root@manager project1]# cat f16.yml
- hosts: all
tasks:
- name: Add Nginx Yum Repository
yum_repository:
name: nginx
description: Nginx Repository
baseurl: http://nginx.org/packages/centos/7/$basearch/
when: ( ansible_hostname is match ("web*"))
[root@manager project1]# cat f17.yml
- hosts: webservers
tasks:
- name: Check Httpd Server
command: systemctl is-active httpd
register: Check_Httpd
ignore_errors: yes
#判断Check_Httpd.rc是否等于0,如果为0则执行任务,否则不执行
- name: Restart Httpd Server
systemd:
name: httpd
state: restarted
when: ( Check_Httpd.rc == 0 )
7.循环语句
例题：
（1）一次启动多个服务
[root@manager project1]# cat f18.yml
- hosts: webservers
tasks:
- name: Systemd Nginx Status
systemd:
name: "{{ item }}" #调用的变量也不变,也是固定
state: started
#固定的语法格式
with_items:
- nginx
- php-fpm
（2）一次拷贝多个文件
[root@manager project1]# cat f19.yml
- hosts: webservers
tasks:
- name: Configure nginx.conf
copy:
src: '{{ item.src }}'
dest: '{{ item.dest }}'
mode: '{{ item.mode }}'
with_items:
- { src: ./file/nginx.conf.j2, dest: /etc/nginx/nginx.conf, mode: '0644' }
- { src: ./file/kold.oldxu.com.conf.j2, dest: /etc/nginx/conf.d/kold.oldxu.com.conf, mode: '0600' }
（3）创建多个用户,一次创建多个? 3个用户
[root@manager project1]# cat f20.yml
- hosts: webservers
tasks:
- name: Create User
user:
name: "{{ item }}"
with_items:
- test1
- test2
- test3
- test4
#.创建tt1 --> bin tt2 -->root tt3 --->adm 附加组
[root@manager project1]# cat f20.yml
- hosts: webservers
tasks:
- name: Create User
user:
name: "{{ item.name }}"
groups: "{{ item.groups }}"
with_items:
- { name: tt1, groups: bin }
- { name: tt2, groups: root }
- { name: tt3, groups: adm }
1.标准循环 --->居多
item
with_items:
- test
2.字典循环: --->居多
itme.name
with_items:
- { name: test }
3.变量循环
- hosts: webservers
tasks:- name: ensure a list of packages installed
yum: name={{ packages }} state=present
vars:
packages:
- httpd
- httpd-tools
- name: ensure a list of packages installed
8.handlers
（1）例题：
[root@manager project1]# cat f22.yml
- hosts: webservers
tasks:
- name: Installed Nginx and PHP Packages
yum:
name: nginx
state: present
- name: Configure nginx.conf
template:
src: ./file/nginx.conf.j2
dest: /etc/nginx/nginx.conf
#监控-->changed状态-->通知-->handlers--->name-->Restart Nginx Server
notify: Restart Nginx Server
#notify:
# - Restart Nginx Server
# - Restart php Server
- name: Systemd Nginx Server
systemd:
name: nginx
state: started
enabled: yes
#当nginx或php配置文件发生变更才会触发此操作
handlers:
- name: Restart Nginx Server
systemd:
name: nginx
state: restarted
（2）handlers注意事项
（1）无论多少个task通知了相同的handlers，handlers仅会在所有tasks结束后运行一次。
（2）只有task发生改变了才会通知handlers，没有改变则不会触发handlers.
（3）不能使用handlers替代tasks、因为handlers是一个特殊的tasks。
