ansible playbook实践(二)-基础相关命令

ansible相关的命令：

ansible  用来执行ansible管理命令

ansible-doc 用来获取模块的帮助文档

ansible-playbook 当有众多任务时，可编写成playbook来运行

ansible的简单使用格式：

ansible HOST-PATTERN -m MOD_NAME -a MOD_ARGS

获取模块列表

ansible-doc -l 里面有众多模块，掌握一些常用的即可满足日常工作

ansible-doc -s modulename # 获取模块简要使用说明

示例：

[root@localhost ~]# ansible-doc -s shell
- name: Execute commands in nodes.
shell:
chdir: # cd into this directory before running the command
creates: # a filename, when it already exists, this step will *not* be run.
executable: # change the shell used to execute the command. Should be an absolute path to the executable.
free_form: # (required) The shell module takes a free form command to run, as a string. There's not an actual option named "free form". See the examples!
removes: # a filename, when it does not exist, this step will *not* be run.
stdin: # Set the stdin of the command directly to the specified value.
warn: # if command warnings are on in ansible.cfg, do not warn about this particular line if set to no/false.

里面标明了各个参数的含义，如果你想更详细的解释，可以把命令行中的-s去掉。

[root@localhost ~]# ansible all -m shell -a "chdir=/tmp date"
192.168.40.72 | SUCCESS | rc=0 >>
Thu Feb 8 10:46:45 CST 2018

192.168.40.73 | SUCCESS | rc=0 >>
Thu Feb 8 10:46:45 CST 2018

对于执行单个简单的模块，我们还可以这样用命令行来编写，但是当我们需要连接执行多个模块时，就得需要用到ansible-playbook命令了。我们可以把需要执行的任务写在一个文件中，然后依次执行。

[root@localhost playbook]# cat first_play.yml
---
- hosts: all
  remote_user: root
  gather_facts: no
  tasks:
    - name: ping test
      ping: 

    - name: execute remote shell
      shell: ps -eo pcpu,user,args | sort -r -k1 | head -n3
      register: ret

    - name: output msg
      debug: var=ret.stdout_lines

执行如下，加上-v（-vv -vvv）参数可以有更详细的信息输出：

[root@localhost playbook]# ansible-playbook -v first_play.yml
Using /etc/ansible/ansible.cfg as config file

PLAY [all] ********************************************************************************

TASK [ping test] **************************************************************************
ok: [192.168.40.72] => {"changed": false, "ping": "pong"}
ok: [192.168.40.73] => {"changed": false, "ping": "pong"}

TASK [execute remote shell] ***************************************************************
changed: [192.168.40.73] => {"changed": true, "cmd": "ps -eo pcpu,user,args | sort -r -k1 | head -n3", "delta": "0:00:00.010615", "end": "2018-02-08 11:04:19.939640", "rc": , "start": "2018-02-08 11:04:19.929025", "stderr": "", "stderr_lines": [], "stdout": "%CPU USER     COMMAND\n 2.0 root     sshd: root@pts/0\n 0.6 root     /usr/bin/vmtoolsd", "stdout_lines": ["%CPU USER     COMMAND", " 2.0 root     sshd: root@pts/0", " 0.6 root     /usr/bin/vmtoolsd"]}
changed: [192.168.40.72] => {"changed": true, "cmd": "ps -eo pcpu,user,args | sort -r -k1 | head -n3", "delta": "0:00:00.013069", "end": "2018-02-08 11:04:19.943902", "rc": , "start": "2018-02-08 11:04:19.930833", "stderr": "", "stderr_lines": [], "stdout": "%CPU USER     COMMAND\n 1.0 root     sshd: root@pts/1\n 0.5 root     /usr/bin/vmtoolsd", "stdout_lines": ["%CPU USER     COMMAND", " 1.0 root     sshd: root@pts/1", " 0.5 root     /usr/bin/vmtoolsd"]}

TASK [output msg] *************************************************************************
ok: [192.168.40.72] => {
    "ret.stdout_lines": [
        "%CPU USER     COMMAND",
        " 1.0 root     sshd: root@pts/1",
        " 0.5 root     /usr/bin/vmtoolsd"
    ]
}
ok: [192.168.40.73] => {
    "ret.stdout_lines": [
        "%CPU USER     COMMAND",
        " 2.0 root     sshd: root@pts/0",
        " 0.6 root     /usr/bin/vmtoolsd"
    ]
}

PLAY RECAP ********************************************************************************
192.168.40.72              : ok=    changed=    unreachable=    failed=
192.168.40.73              : ok=    changed=    unreachable=    failed=   

playbook采用yaml语法来编写，下一篇我们就来讲如何编写yaml文件。