CentOS7 安装 Ansible

CentOS7 安装 Ansible

Ansible是一款为类Unix系统开发的自由开源的配置和自动化工具。它用Python写成，类似于Chef和Puppet，但是有一个不同和优点是我们不需要在节点中安装任何客户端。它使用SSH来和节点进行通信。

本篇中我们将在CentOS 7上安装并配置Ansible，并且尝试管理两个节点。
* Ansible 服务端 – hostname:artemis.dbs.wx.com ( 192.168.56.211 )
* 节点: hostname:apollo.dbs.wx.com ( 192.168.56.212 )
* 节点: hostname:uranus.dbs.wx.com ( 192.168.56.213 )

设置EPEL仓库

[root@artemis ~]# wget http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm

使用yum安装epel

[root@artemis ~]# rpm -ivh epel-release-latest-7.noarch.rpm

安装完成后，检查ansible版本

#安装
[root@artemis ~]# yum -y install ansible
#版本
[root@artemis ~]# ansible --version
ansible 2.2.1.0
  config file = /etc/ansible/ansible.cfg
  configured module search path = Default w/o overrides

设置用于节点鉴权的SSH密钥

在Ansible服务端生成密钥，并且复制公钥到节点中

[root@artemis ~]# ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
93:f0:ed:ba:e7:d4:0b:55:ef:87:b4:57:a9:3f:28:eb root@artemis.dbs.wx.com
The key's randomart image is:
+--[ RSA 2048]----+
|                 |
|                 |
|      .       .  |
|       o o   . ..|
|        S . . ..o|
|         o o ..+.|
|          + ..+ +|
|         o.o o.o.|
|        o+oE+  ..|
+-----------------+

使用ssh-copy-id命令来复制Ansible公钥到节点中

#添加到节点212:
[root@artemis ~]# ssh-copy-id -i [email protected]
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.56.212's password:

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh '[email protected]'"
and check to make sure that only the key(s) you wanted were added.
#添加到节点213:
[root@artemis ~]# ssh-copy-id -i [email protected]
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.56.213's password:

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh '[email protected]'"
and check to make sure that only the key(s) you wanted were added.

为Ansible定义节点的清单

文件 /etc/ansible/hosts 维护着Ansible中服务器的清单。

[root@artemis ~]# vi /etc/ansible/hosts

[dbservers]
192.168.56.212
192.168.56.213

尝试在Ansible服务端运行命令

[root@artemis ~]# ansible -m ping 'dbservers'
192.168.56.213 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
192.168.56.212 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}

执行shell命令

例子1：检查Ansible节点的运行时间（uptime):

[root@artemis ~]# ansible -m command -a "uptime" 'dbservers'
192.168.56.213 | SUCCESS | rc=0 >>
 23:31:25 up 49 min,  2 users,  load average: 0.00, 0.01, 0.05

192.168.56.212 | SUCCESS | rc=0 >>
 23:31:25 up  1:22,  2 users,  load average: 0.00, 0.01, 0.05

例子2：检查节点的内核版本

[root@artemis ~]# ansible -m command -a "uname -r" 'dbservers'
192.168.56.212 | SUCCESS | rc=0 >>
3.10.0-123.el7.x86_64

192.168.56.213 | SUCCESS | rc=0 >>
3.10.0-123.el7.x86_64

例子3：给节点增加用户

[root@artemis ~]# ansible -m command -a "useradd david" 'dbservers'
192.168.56.212 | SUCCESS | rc=0 >>


192.168.56.213 | SUCCESS | rc=0 >>


[root@artemis ~]# ansible -m command -a "grep david /etc/passwd" 'dbservers'
192.168.56.212 | SUCCESS | rc=0 >>
david:x:1001:1001::/home/david:/bin/bash

192.168.56.213 | SUCCESS | rc=0 >>
david:x:1001:1001::/home/david:/bin/bash

例子4：重定向输出到文件中

[root@artemis ~]# ansible -m command -a "df -Th" 'dbservers' > /tmp/command-output.txt
[root@artemis ~]# cat /tmp/command-output.txt
192.168.56.212 | SUCCESS | rc=0 >>
Filesystem              Type      Size  Used Avail Use% Mounted on
/dev/mapper/centos-root xfs        39G  2.4G   37G   7% /
devtmpfs                devtmpfs  915M     0  915M   0% /dev
tmpfs                   tmpfs     921M     0  921M   0% /dev/shm
tmpfs                   tmpfs     921M  8.4M  913M   1% /run
tmpfs                   tmpfs     921M     0  921M   0% /sys/fs/cgroup
/dev/mapper/centos-home xfs        19G  590M   19G   4% /home
/dev/sda1               xfs       497M   96M  402M  20% /boot
192.168.56.213 | SUCCESS | rc=0 >>
Filesystem              Type      Size  Used Avail Use% Mounted on
/dev/mapper/centos-root xfs        39G  2.4G   37G   7% /
devtmpfs                devtmpfs  915M     0  915M   0% /dev
tmpfs                   tmpfs     921M     0  921M   0% /dev/shm
tmpfs                   tmpfs     921M   17M  905M   2% /run
tmpfs                   tmpfs     921M     0  921M   0% /sys/fs/cgroup
/dev/mapper/centos-home xfs        19G  590M   19G   4% /home
/dev/sda1               xfs       497M  132M  366M  27% /boot
tmpfs                   tmpfs     185M     0  185M   0% /run/user/0