ansible 学习笔记

一、基础知识：

1. 简介

ansible基于python开发，集合了众多运维工具的优点，实现了批量系统配置、批量程序部署、批量运行命令等功能。ansible是基于模块工作的，本身没有批量部署的能力。
真正具有批量部署的是ansible运行的模块，ansible只是一个框架

(1) 连接插件connection plugins: 负责和被监控端实现通信；
(2) host inventory: 指定操作的主机，是一个配置文件里面定义监控的主机
(3) 各种模块核心模块、command模块、自定义模块；
(4) 借助于插件完成记录日志邮件等功能；
(5) playbook: 剧本执行多个任务时，非必须可以让节点一次性运行多个任务。

2、特性：

(1) no agents: 不需要在被管理主机上安装任务agent
(2) no server: 无服务器端，使用时，直接运行命令即可
(3) modules in any languages: 基于模块工作，可使用任意语言开发模块
(4) yaml not code：使用yaml语言定制剧本playbook
(5) ssh by default：基于SSH工作
(6) strong multi-tier solution: 可实现多级指挥

3、优点：

(1) 轻量级，无需在客户端安装agent，更新时，只需要在操作机上进行一次更新即可；
(2) 批量任务可以写成脚本，而且不用分发到远程就可以执行
(3) 使用python编写，维护简单
(4) 支持sudo

二、ansible安装

1.1 rpm包安装
epel源：

[epel]
name=Extra Packages for Enterprise Linux 6 - $basearch
baseurl=http://download.fedoraproject.org/pub/epel/6/$basearch
#mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-6&arch=$basearch
failovermethod=priority
enabled=1
gpgcheck=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6

[epel-debuginfo]
name=Extra Packages for Enterprise Linux 6 - $basearch - Debug
baseurl=http://download.fedoraproject.org/pub/epel/6/$basearch/debug
#mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-debug-6&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
gpgcheck=0

[epel-source]
name=Extra Packages for Enterprise Linux 6 - $basearch - Source
baseurl=http://download.fedoraproject.org/pub/epel/6/SRPMS
#mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-source-6&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
gpgcheck=0

[root@localhost ~]# yum install ansible -y

三、常用模块介绍

copy模块
目的：把主控本地文件拷贝到远程节点上

[root@localhost ~]# ansible 192.168.118.14 -m copy -a "src=/root/bigfile dest=/tmp"
192.168.118.14 | SUCCESS => {
"changed": true,
"checksum": "8c206a1a87599f532ce68675536f0b1546900d7a",
"dest": "/tmp/bigfile",
"gid": 0,
"group": "root",
"md5sum": "f1c9645dbc14efddc7d8a322685f26eb",
"mode": "0644",
"owner": "root",
"size": 10485760,
"src": "/root/.ansible/tmp/ansible-tmp-1467946691.02-193284383894106/source",
"state": "file",
"uid": 0
}

file模块
目的：更改指定节点上文件的权限、属主和属组

[root@localhost ~]# ansible 192.168.118.14 -m file -a "dest=/tmp/bigfile mode=777 owner=root group=root"
192.168.118.14 | SUCCESS => {
"changed": true,
"gid": 0,
"group": "root",
"mode": "0777",
"owner": "root",
"path": "/tmp/bigfile",
"size": 10485760,
"state": "file",
"uid": 0
}

cron模块
目的：在指定节点上定义一个计划任务，每三分钟执行一次。

[root@localhost ~]# ansible all -m cron -a 'name="Cron job" minute=*/3 hour=* day=* month=* weekday=* job="/usr/bin/ntpdate tiger.sina.com.cn"'
192.168.118.14 | SUCCESS => {
"changed": true,
"envs": [],
"jobs": [
"Cron job"
]
}
192.168.118.13 | SUCCESS => {
"changed": true,
"envs": [],
"jobs": [
"Cron job"
]
}

group模块
目的：在远程节点上创建一个组名为ansible，gid为2016的组

[root@localhost ~]# ansible 192.168.118.14 -m group -a "name=ansible gid=2016"
192.168.118.14 | SUCCESS => {
"changed": true,
"gid": 2016,
"name": "ansible",
"state": "present",
"system": false
}

user模块
目的：在指定节点上创建一个用户名为ansible，组为ansible的用户

[root@localhost ~]# ansible 192.168.118.14 -m user -a "name=ansible uid=2016 group=ansible state=present"
192.168.118.14 | SUCCESS => {
"changed": true,
"comment": "",
"createhome": true,
"group": 2016,
"home": "/home/ansible",
"name": "ansible",
"shell": "/bin/bash",
"state": "present",
"system": false,
"uid": 2016
}

删除远端节点用户，注意：删除远程用户，但是不会删除该用户的家目录

[root@localhost ~]# ansible 192.168.118.14 -m user -a "name=ansible state=absent"
192.168.118.14 | SUCCESS => {
"changed": true,
"force": false,
"name": "ansible",
"remove": false,
"state": "absent"
}

yum 模块
目的：在远程节点安装vsftpd

[root@localhost ~]# ansible 192.168.118.14 -m yum -a 'name=vsftpd state=present'
192.168.118.14 | SUCCESS => {
"changed": true,
"msg": "",
"rc": 0,
"results": [
"Loaded plugins: fastestmirror\nSetting up Install Process\nLoading mirror speeds from cached hostfile\nResolving Dependencies\n--> Running transaction check\n---> Package vsftpd.x86_64 0:2.2.2-14.el6 will be installed\n--> Finished Dependency Resolution\n\nDependencies Resolved\n\n================================================================================\n Package          Arch             Version                  Repository     Size\n================================================================================\nInstalling:\n vsftpd           x86_64           2.2.2-14.el6             yum           152 k\n\nTransaction Summary\n================================================================================\nInstall       1 Package(s)\n\nTotal download size: 152 k\nInstalled size: 332 k\nDownloading Packages:\nRunning rpm_check_debug\nRunning Transaction Test\nTransaction Test Succeeded\nRunning Transaction\n\r  Installing : vsftpd-2.2.2-14.el6.x86_64                                   1/1 \n\r  Verifying  : vsftpd-2.2.2-14.el6.x86_64                                   1/1 \n\nInstalled:\n  vsftpd.x86_64 0:2.2.2-14.el6                                                  \n\nComplete!\n"
]
}

卸载写法：

[root@localhost ~]# ansible 192.168.118.14 -m yum -a 'name=vsftpd state=removed'
192.168.118.14 | SUCCESS => {
"changed": true,
"msg": "",
"rc": 0,
"results": [
"Loaded plugins: fastestmirror\nSetting up Remove Process\nResolving Dependencies\n--> Running transaction check\n---> Package vsftpd.x86_64 0:2.2.2-14.el6 will be erased\n--> Finished Dependency Resolution\n\nDependencies Resolved\n\n================================================================================\n Package          Arch             Version                 Repository      Size\n================================================================================\nRemoving:\n vsftpd           x86_64           2.2.2-14.el6            @yum           332 k\n\nTransaction Summary\n================================================================================\nRemove        1 Package(s)\n\nInstalled size: 332 k\nDownloading Packages:\nRunning rpm_check_debug\nRunning Transaction Test\nTransaction Test Succeeded\nRunning Transaction\n\r  Erasing    : vsftpd-2.2.2-14.el6.x86_64                                   1/1 \n\r  Verifying  : vsftpd-2.2.2-14.el6.x86_64                                   1/1 \n\nRemoved:\n  vsftpd.x86_64 0:2.2.2-14.el6                                                  \n\nComplete!\n"
]
}

service模块

启动
[root@localhost ~]# ansible 192.168.118.14 -m service -a 'name=vsftpd state=started enabled=yes'
192.168.118.14 | SUCCESS => {
"changed": true,
"enabled": true,
"name": "vsftpd",
"state": "started"
}
停止
[root@localhost ~]# ansible 192.168.118.14 -m service -a 'name=vsftpd state=stopped enabled=yes'
192.168.118.14 | SUCCESS => {
"changed": true,
"enabled": true,
"name": "vsftpd",
"state": "stopped"
}

ping模块

[root@localhost ~]# ansible 192.168.118.14 -m ping
192.168.118.14 | SUCCESS => {
"changed": false,
"ping": "pong"
}

command模块

[root@localhost ~]# ansible 192.168.118.14 [-m command] -a 'w'    # -m command可以省略就表示使用命名模块
192.168.118.14 | SUCCESS | rc=0 >>
14:00:32 up  3:51,  2 users,  load average: 0.00, 0.00, 0.00
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
root     pts/0    192.168.118.69   18:09    3:29   0.12s  0.12s -bash
root     pts/1    192.168.118.13   14:00    0.00s  0.04s  0.00s /bin/sh -c LANG

raw模块

主要的用途是在command中添加管道符号

[root@localhost ~]# ansible 192.168.118.14 -m raw -a 'hostname | tee'
192.168.118.14 | SUCCESS | rc=0 >>
localhost.localdomain

get_url模块

目的：将http://192.168.118.14/1.png 下载到本地

[root@localhost ~]# ansible 192.168.118.14 -m get_url -a 'url=http://192.168.118.14/1.png dest=/tmp'
192.168.118.14 | SUCCESS => {
"changed": true,
"checksum_dest": null,
"checksum_src": "ba5cb18463ecfa13cdc0b611c9c10875275d883e",
"dest": "/tmp/1.png",
"gid": 0,
"group": "root",
"md5sum": "8c0df0b008eb5735dc955171d6d9dd73",
"mode": "0644",
"msg": "OK (14987 bytes)",
"owner": "root",
"size": 14987,
"src": "/tmp/tmpY2lqHF",
"state": "file",
"uid": 0,
"url": "http://192.168.118.14/1.png"
}

synchronize模块

目的：将主空方目录推送到指定节点/tmp目录下

[root@localhost ~]# ansible 192.168.118.14 -m synchronize -a 'src=/root/test dest=/tmp/ compress=yes'
192.168.118.14 | SUCCESS => {
"changed": true,
"cmd": "/usr/bin/rsync --delay-updates -F --compress --archive --rsh 'ssh  -S none -o StrictHostKeyChecking=no' --out-format='<<CHANGED>>%i %n%L' \"/root/test\" \"192.168.118.14:/tmp/\"",
"msg": ".d..t...... test/\n<f+++++++++ test/abc\n",
"rc": 0,
"stdout_lines": [
".d..t...... test/",
"<f+++++++++ test/abc"
]
}

四、ansible playbooks

4.1 http安装：

- hosts: web
vars:
http_port: 80
max_clients: 256
remote_user: root

tasks:
- name: ensure apache is at the latest version
yum: name=httpd state=latest
- name: ensure apache is running
service: name=httpd state=started

4.2 mysql安装

- hosts: 192.168.118.14
vars:
remote_user: root
max_clients: 256
mysql_name: "mysql-server"
tasks:
- name: ensure install mysql
yum: name="{{mysql_name}}" state=present
- name: ensure apache is running
service: name=mysqld state=started

1. handlers
用于当关注的资源发生变化时采取一定的操作.

“notify”这个action可用于在每个play的最后被触发，这样可以避免多次有改变发生时每次都执行指定的操作，取而代之，仅在所有的变化发生完成后一次性地执行指定操作。在notify中列出的操作称为handler，也即notify中调用handler中定义的操作。

1 - hosts: web
2   remote_user: root
3   tasks:
4   - name: install apache
5     yum: name=httpd
6   - name: install config
7     copy: src=/etc/httpd/conf/httpd.conf dest=/etc/httpd/conf/httpd.conf
8     notify:
9     - restart httpd        # 这触发 restart httpd 动作
10   - name: start httpd
11     service: name=httpd state=started
12   handlers:
13   - name: restart httpd
14     service: name=httpd state=restarted

注意：测试使用ansible2.1版本，每执行一次如上脚本，- name: start httpd都会执行一次，因此可以不用使用handlers

2. 调用setup模块中的变量

1 - hosts: web
2   remote_user: root
3   tasks:
4   - name: copy file
5     copy: content="{{ansible_all_ipv4_addresses}}" dest=/tmp/a.txt

3. when 条件判断

1 - hosts: all
2   remote_user: root
3   vars:
4   - username: test
5   tasks:
6   - name: create {{ username }} user.
7     user: name={{ username }}
8     when: ansible_fqdn == "localhost.localdomain"    # 当条件匹配到，才会创建test用户

4. 使用with_items进行迭代

1 - hosts: web
2   remote_user: root
3   tasks:
4   - name: yum install packages
5     yum: name={{ item.name }} state=present
6     with_items:
7       - { name: 'mysql-server' }
8       - { name: 'vsftpd' }

5. template 使用

使用场景： 当多个服务修改的参数不一致时。

拷贝/etc/httpd/conf/httpd.conf到指定目录，修改Listen使用变量
Listen {{ http_port }}

在ansible hosts中定义变量
14 [web]
15 192.168.2.12 http_port=8000

剧本写法：
8 - name: install config
9 template: src=/root/temp/{{http_name}}.j2 dest=/etc/httpd/conf/httpd.conf # 使用template模块

[root@ansible ~]# cat httpd.yml
- hosts: all
remote_user: root
tasks:
- name: install http
yum: name=httpd state=present
- name: copy file
template: src=/root/httpd.j2 dest=/etc/httpd/conf/httpd.conf
notify:
- restart httpd
- name: restart httpd
service: name=httpd state=started

handlers:
- name: restart httpd
service: name=httpd state=restarted

[web]
192.168.118.14 ansible_ssh_user=root ansible_ssh_pass=123456 ansible_ssh_port=22 http_port=8888 maxClients=50
[myhost]
192.168.118.49 ansible_ssh_user=root ansible_ssh_pass=123456 ansible_ssh_port=22 http_port=9999 maxClients=100

6. tag的使用

使用场景：当一个playbook只需要执行某一个步骤的时候定义

剧本写法

9     template: src=/root/temp/{{http_name}}.j2 dest=/etc/httpd/conf/httpd.conf
10     tags:
11     - conf

7. roles的用法：

mkdir -pv ansible_playbooks/roles/web/{templates,files,vars,tasks,meta,handlers}
cp -a /etc/httpd/conf/httpd.conf files/
vim tasks/main.yml
1 - name: install httpd
2   yum: name=httpd
3 - name: install configuration file
4   copy: src=httpd.conf dest=/etc/httpd/conf/httpd.conf
5   tags:
6   - conf
7   notify:
8   - restart httpd
9 - name: start httpd
10   service: name=httpd state=started

vim handlers/main.yml
1 - name: restart httpd
2   service: name=httpd state=restarted

[root@server1 ansible_playbooks]# ls
roles  site.yml
[root@server1 ansible_playbooks]# vim site.yml
1 - hosts: web
2   remote_user: root
3   roles:
4   - web
[root@server1 ansible_playbooks]ansible-playbook site.yml