# 自动化运维工具ansible
## 1.安装
```
yum install -y ansible cowsay
```
## 2.配置
```
vim /etc/ansible/hosts
```
将要管理的主机加入配置文件，前提要做好ssh-key秘钥登录，这里不做描述
```
[nodes]
192.168.2.4
192.168.2.5
192.168.2.6
```
## 3.常用模块
`ping`模块：检测被控主机是否能ping通
```shell
ansible nodes -m ping #ansible后加主机可以是all、在hosts文件配置的标签如nodes、或者ip，-m指定模块
```
`command`模块：执行命令，只能执行简单的命令，无法解释特殊符号，如管道|,统配*等等，不指定模块默认是执行此模块
```shell
ansible all -m command -a "ifconfig" #-a后指定动作
```
`shell`模块：
```shell
ansible all -m shell -a "hostname >/tmp/hostname.txt"
```
`copy`模块：把管理机的文件复制到被控主机
```shell
ansibe all -m copy -a "src=/scripts/lnmp.sh dest=/root"
```
```shell
ansibe all -m copy -a "src=/scripts/lnmp.sh dest=/root/LNMP.sh owner=nobody group=nobody mode=700"
```
`script`模块：相当于结合`shell`模块和`copy`模块，先把脚本传到服务器上再执行
```shell
ansible all -m script -a "/scripts/lnmp.sh"
```
`file`模块：修改文件用户，组，权限，路径，创建目录或文件
要指定path，state(directory|touch|link)
```shell
ansible all -m file -a "path=/www state=directory"
```
`yum`模块：指定包名，版本state有：present,latest
```shell
ansible all -m yum -a "name=nginx state=present"
```
`cron`模块：定时任务，相当于`vi /var/spool/cron/root`
```shell
ansible all -m cron -a 'name="backup etc" minute=00 hour=00 job="tar zcf /tmp/backup.tar.gz /backup/* >/dev/null 2>&1" state=present'
```
删除某个定时任务，指定state为adsent即可
```shell
ansible all -m cron -a 'name="backup etc" state=absent'
```
## 3.playbook剧本
```
vim /etc/ansible/xxx.yml
```
```yaml
---
- hosts: all
task:
- name: show hostname
command: hostname
```
执行
```shell
ansible-playbook -C /etc/ansible/xxx.yml #检测playbook语法是否正确
```
```shell
ansible-playbook /etc/ansible/xxx.yml
```
添加定时任务，如cron.yml
```yaml
---
- hosts: all
tasks:
- name: add cron
cron:
name: "backup etc"
minute: 00
hour: 00
job: "tar zcf /tmp/backup.tar.gz /backup/* >/dev/null 2>&1"
state: present
```
## 4.absible注册变量
在playbook里使用变量，使用vars定义好后，用连个花括号表示引用`{{}}`
```yaml
---
- hosts: all
vars:
file: shz.txt
dir: /root/
tasks:
- name: touch file
file: path={{dir}}/{{file}} state=touch
```
使用系统命令作为变量
```yaml
---
- hosts: all
tasks:
- name: get ip address
shell: hostname -I
register: ip
- name: print ip var to file
shell: echo {{ip.stdout}} >/tmp/ip.txt
```
如下实例一个打包备份配置文件的playbook
```yaml
---
- hosts: all
tasks:
- name: get ip
shell: hostname -I
register: ip
- name: get date
shell: date +%F
register: date
- name: mkdir
file: path=/backup/{{ip.stdout}} state=directory
- name: tar
shell: tar zcf /backup/etc-{{ip.stdout}}-{{date.stdout}}.tar.gz /etc/*
```
如何调试变量
`debug`模块：msg={{xxx}}
```yaml
---
- hosts: all
tasks:
- name: get ip
shell: hostname -I
register: ip
- name: debug test
debug: msg={{ip}}
```
然后直接执行即可，不需要`-C`检查错误
## 5.ansible循环和判断
循环
```yaml
---
- hosts: all
tasks:
- name: show ip
shell: echo 192.168.2.{{item}} >/tmp/test1.txt
with_items:
- 4
- 5
- 6
```
条件，when指定主机名 `ansible_hostname`叫做ansible内置变量
```yaml
---
- hosts: all
tasks:
- name: install nfs
yum: name=nfs-utils,rpcbind state=present
when: ( ansible_hostname == "node3" )
```
查看ansible所有内置变量
```
ansible 192.168.2.5 -m setup
```
