不求甚解--详解ansible-playbook中roles的用法

前言

本文将详细介绍ansible-playbook中roles的各种用法,它允许你将相关的任务、变量、处理器、文件和模板等集合在一起,以便于在不同的项目中复用

环境准备

组件 版本
操作系统 Ubuntu 22.04.4 LTS
ansible 2.17.6

基本用法

文件结构

.
├── deploy.hosts
├── deploy.yaml
└── roles
    └── base
        └── tasks
            └── main.yaml

  • deploy.hosts作为目标机器的列表文件
    ▶ cat deploy.hosts
    10.22.11.166
    
  • deploy.yaml作为入口文件
    ▶ cat deploy.yaml
    - name: deploy
      hosts: all
      remote_user: wilson
      gather_facts: no
      vars:
        ansible_ssh_pass: '123456'
        ansible_python_interpreter: /usr/bin/python3
      roles:
        - base
    
    • name:指定作业的名字:deploy
    • hosts:all代表deploy.hosts文件中所有的机器(也可以指定机器的分类信息)
    • remote_user:目标机器的登录用户
    • gather_facts: 是否需要采集目标机器的基本数据,默认采集。脚本指定的是不采集,为了提高执行速度
    • vars.ansible_ssh_oass:目标机器登录用户的密码
    • vars.ansible_python_interpreter:目标机器python3的路径
    • roles:指定本次作业所使用的角色 base
  • roles目录作为ansible-playbook中一系列作业任务的集合,其中一个集合的名字叫做base
    • tasks中的main.yaml作为base的入口文件
      ▶ cat roles/base/tasks/main.yaml
      - name: first
        command: echo 'hello world'
      
      • base当前只有1个任务,就是登录到目标机器,执行hello world

运行

▶ ansible-playbook -i deploy.hosts deploy.yaml

PLAY [deploy] ****************************************************************************************************

TASK [base : first] **********************************************************************************************
changed: [10.22.11.166]

PLAY RECAP *******************************************************************************************************
10.22.11.166               : ok=1    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

在屏幕上显示执行结果

需要改造roles/base/tasks/main.yaml

▶ cat roles/base/tasks/main.yaml
- name: first
  command: echo 'hello world'
  register: display_result
- name: display
  debug:
    msg: "{{ display_result }}"

把结果放入变量display_result,然后通过模版语言打印出来,并且是json格式的

运行:

▶ ansible-playbook -i deploy.hosts deploy.yaml

PLAY [deploy] ****************************************************************************************************

TASK [base : first] **********************************************************************************************
changed: [10.22.11.166]

TASK [base : display] ********************************************************************************************
ok: [10.22.11.166] => {
    "msg": {
        "changed": true,
        "cmd": [
            "echo",
            "hello world"
        ],
        "delta": "0:00:00.002740",
        "end": "2024-11-19 07:22:22.226036",
        "failed": false,
        "msg": "",
        "rc": 0,
        "start": "2024-11-19 07:22:22.223296",
        "stderr": "",
        "stderr_lines": [],
        "stdout": "hello world",
        "stdout_lines": [
            "hello world"
        ]
    }
}

PLAY RECAP *******************************************************************************************************
10.22.11.166               : ok=2    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

引用环境变量

将操作系统的环境变量传入,可以通过lookup来引用,比如:要使用PATH,可以通过lookup('env', 'PATH')

改造roles/base/tasks/main.yaml

▶ cat roles/base/tasks/main.yaml
- name: first
  debug:
    msg: "{{ lookup('env', 'PATH') }}"

运行:

▶ ansible-playbook -i deploy.hosts deploy.yaml

PLAY [deploy] ****************************************************************************************************

TASK [base : first] **********************************************************************************************
ok: [10.22.11.166] => {
    "msg": "/home/wilson/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/snap/bin:/usr/local/go/bin:/usr/local/go/bin"
}

PLAY RECAP *******************************************************************************************************
10.22.11.166               : ok=1    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

使用ansible变量

这里的ansible变量,其中一部分ansible默认的变量,一部分是ansible运行的时候,会默认去采集目标机器的基本信息,比如操作系统、cpu、内存、磁盘等等的基本信息

部分内置变量

变量名 描述
inventory_hostname 当前任务执行的主机名(来自 Inventory 文件)
ansible_facts 包含所有收集到的主机事实(facts)
hostvars 所有主机变量的集合,包含当前和其他主机

采集目标机器的基本信息

需要把之前采集ansible基本信息的开关打开gather_facts: yes,打开之后会牺牲运行速度

改造roles/base/tasks/main.yaml

- name: first
  debug:
    msg: "{{ hostvars }}"

运行:

由于数据量太大,只展示部分,并且json格式,可以直接拿想要的值

▶ ansible-playbook -i deploy.hosts deploy.yaml

PLAY [deploy] ******************************************************************

TASK [Gathering Facts] *********************************************************
ok: [10.22.11.166]

TASK [base : first] ************************************************************
ok: [10.22.11.166] => {
    "msg": {
        "10.22.11.166": {
            "ansible_all_ipv4_addresses": [
                "10.22.11.166"
            ],
            "ansible_all_ipv6_addresses": [
                "fe80::a00:27ff:fef6:82c4"
            ],
            "ansible_apparmor": {
                "status": "enabled"
            },
            "ansible_architecture": "x86_64",
            "ansible_bios_date": "12/01/2006",
            "ansible_bios_vendor": "innotek GmbH",
            "ansible_bios_version": "VirtualBox",
            "ansible_board_asset_tag": "NA",
            "ansible_board_name": "VirtualBox",
            "ansible_board_serial": "NA",
            "ansible_board_vendor": "Oracle Corporation",
            ...
            "inventory_dir": "/home/wilson/workspace/ansible",
            "inventory_file": "/home/wilson/workspace/ansible/deploy.hosts",
            "inventory_hostname": "10.22.11.166",
            "inventory_hostname_short": "10.22.11.166",
            "module_setup": true,
            "playbook_dir": "/home/wilson/workspace/ansible"
        }
    }
}

PLAY RECAP *********************************************************************
10.22.11.166               : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

是否采集目标的基本信息

上面已经演示过,只需要gather_facts: yes即可

从命令行传入变量

ansible-playbook可以通过-e传入变量使用

▶ cat roles/base/tasks/main.yaml
- name: first
  debug:
    msg: "{{ app_name }} - {{ app_version }}"

运行:

▶ ansible-playbook -i deploy.hosts -e "app_name=prom app_version=1.0" deploy.yaml

PLAY [deploy] ****************************************************************************************************

TASK [Gathering Facts] *******************************************************************************************
ok: [10.22.11.166]

TASK [base : first] **********************************************************************************************
ok: [10.22.11.166] => {
    "msg": "prom - 1.0"
}

PLAY RECAP *******************************************************************************************************
10.22.11.166               : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

动态选择host

1)将主机分组

修改deploy.hosts文件

▶ cat deploy.hosts
[ga]
10.22.11.166

[gb]
10.22.11.166
127.0.0.1

2)改造入口文件

▶ cat deploy.yaml
- name: deploy
  hosts: '{{h}}'
  remote_user: wilson
  gather_facts: no
  vars:
    ansible_ssh_pass: '123456'
    ansible_python_interpreter: /usr/bin/python3
  roles:
    - base

将hosts改在成为'{{h}}',通过传入h变量来动态定义

3)运行

指定h为ga

▶ ansible-playbook -i deploy.hosts -e "h=ga" deploy.yaml

PLAY [deploy] ****************************************************************************************************

TASK [base : first] **********************************************************************************************
ok: [10.22.11.166] => {
    "msg": "hello world"
}

PLAY RECAP *******************************************************************************************************
10.22.11.166               : ok=1    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

指定h为gb

▶ ansible-playbook -i deploy.hosts -e "h=gb" deploy.yaml

PLAY [deploy] ****************************************************************************************************

TASK [base : first] **********************************************************************************************
ok: [10.22.11.166] => {
    "msg": "hello world"
}
ok: [127.0.0.1] => {
    "msg": "hello world"
}

PLAY RECAP *******************************************************************************************************
10.22.11.166               : ok=1    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0
127.0.0.1                  : ok=1    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

条件选择when

▶ cat roles/base/tasks/main.yaml
- name: first
  debug:
    msg: "version 1"
  when: version == '1'

- name: second
  debug:
    msg: "version 2"
  when: version == '2'

定义临时变量

通过-e传入的变量来产生临时变量

- name: first
  set_fact:
    tag: "hello-{{ version }}"

- name: second
  debug:
    msg: "{{ tag }}"

运行:

▶ ansible-playbook -i deploy.hosts -e "version=2" deploy.yaml

...

TASK [base : second] *********************************************************************************************
ok: [10.22.11.166] => {
    "msg": "hello-2"
}

...

调用多个role

1)新增role: advance

.
├── deploy.hosts
├── deploy.yaml
└── roles
    ├── advance
    │   └── tasks
    │       └── main.yaml
    └── base
        └── tasks
            └── main.yaml

2)直接在入口文件deploy.yaml引用

.
├── deploy.hosts
├── deploy.yaml
└── roles
    ├── advance
    │   └── tasks
    │       └── main.yaml
    └── base
        └── tasks
            └── main.yaml

运行:

▶ ansible-playbook -i deploy.hosts -e "version=2" deploy.yaml

PLAY [deploy] ****************************************************************************************************

TASK [base : first] **********************************************************************************************
ok: [10.22.11.166]

TASK [base : second] *********************************************************************************************
ok: [10.22.11.166] => {
    "msg": "hello-2"
}

TASK [advance : new-first] ***************************************************************************************
ok: [10.22.11.166] => {
    "msg": "new hello world"
}

PLAY RECAP *******************************************************************************************************
10.22.11.166               : ok=3    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

3)在roles base中引用 advance

▶ cat deploy.yaml
- name: deploy
  hosts: all
  remote_user: wilson
  gather_facts: no
  vars:
    ansible_ssh_pass: '123456'
    ansible_python_interpreter: /usr/bin/python3
  roles:
    - base

▶ cat roles/base/tasks/main.yaml
- name: base first
  debug:
    msg: "base {{ version }}"

- name: base second
  include_role:
    name: advance
  vars:
    role_pipe_from_base: "hello world from base"

- name: base third
  debug:
    msg: "{{ role_pipe_from_advance }}"
▶ cat roles/advance/tasks/main.yaml
- name: advance first
  debug:
    msg: "advance {{ version }}"

- name: advance second
  debug:
    msg: "{{ role_pipe_from_base }}"

- name: advance third
  set_fact:
    role_pipe_from_advance: "hello world from advance"

运行:

▶ ansible-playbook -i deploy.hosts -e "version=2" deploy.yaml

PLAY [deploy] ****************************************************************************************************

TASK [base : base first] *****************************************************************************************
ok: [10.22.11.166] => {
    "msg": "base 2"
}

TASK [base second] ***********************************************************************************************
included: advance for 10.22.11.166

TASK [advance : advance first] ***********************************************************************************
ok: [10.22.11.166] => {
    "msg": "advance 2"
}

TASK [advance : advance second] **********************************************************************************
ok: [10.22.11.166] => {
    "msg": "hello world from base"
}

TASK [advance : advance third] ***********************************************************************************
ok: [10.22.11.166]

TASK [base : base third] *****************************************************************************************
ok: [10.22.11.166] => {
    "msg": "hello world from advance"
}

PLAY RECAP *******************************************************************************************************
10.22.11.166               : ok=6    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

这个例子呈现了:

  • 传入变量version是共用的
  • 如何在role传递参数
  • 执行过程中定义的临时变量role_pipe_from_advance可以跨role持续
  • 多role执行是串行的

小结

  • 联系我,做深入的交流


至此,本文结束
在下才疏学浅,有撒汤漏水的,请各位不吝赐教...

posted @ 2024-12-10 10:20  it排球君  阅读(105)  评论(0编辑  收藏  举报