Ansible Playbook目录结构详解

顶层目录结构应当包括下列文件和目录

production                # inventory file for production servers 关于生产环境服务器的清单文件
stage                     # inventory file for stage environment 关于 stage 环境服务器的清单文件

group_vars/
   group1                 # here we assign variables to particular groups 这里我们给特定的组定义变量
   group2                 # ""
host_vars/
   hostname1              # if systems need specific variables, put them here 如果系统需要特定的变量,把它们放置在这里.
   hostname2              # ""

library/                  # if any custom modules, put them here (optional) 如果有自定义的模块,放在这里(可选)
filter_plugins/           # if any custom filter plugins, put them here (optional) 如果有自定义的过滤插件,放在这里(可选)

site.yml                  # master playbook  主 playbook
webservers.yml            # playbook for webserver tier  Web 服务器的 playbook
dbservers.yml             # playbook for dbserver tier  数据库服务器的 playbook

roles/
    common/               # this hierarchy represents a "role" 这里的结构代表了一个 "role"
        tasks/            #
            main.yml      #  <-- tasks file can include smaller files if warranted
        handlers/         #
            main.yml      #  <-- handlers file
        templates/        #  <-- files for use with the template resource
            ntp.conf.j2   #  <------- templates end in .j2
        files/            #
            bar.txt       #  <-- files for use with the copy resource
            foo.sh        #  <-- script files for use with the script resource
        vars/             #
            main.yml      #  <-- variables associated with this role
        defaults/         #
            main.yml      #  <-- default lower priority variables for this role
        meta/             #
            main.yml      #  <-- role dependencies

    webtier/              # same kind of structure as "common" was above, done for the webtier role
    monitoring/           # ""
    fooapp/               # ""

file: production

[atlanta-webservers]
www-atl-1.example.com
www-atl-2.example.com

[boston-webservers]
www-bos-1.example.com
www-bos-2.example.com

[atlanta-dbservers]
db-atl-1.example.com
db-atl-2.example.com

[boston-dbservers]
db-bos-1.example.com

# webservers in all geos
[webservers:children]
atlanta-webservers
boston-webservers

# dbservers in all geos
[dbservers:children]
atlanta-dbservers
boston-dbservers

# everything in the atlanta geo
[atlanta:children]
atlanta-webservers
atlanta-dbservers

# everything in the boston geo
[boston:children]
boston-webservers
boston-dbservers

file: group_vars/atlanta

ntp: ntp-atlanta.example.com
backup: backup-atlanta.example.com

file: group_vars/webservers

apacheMaxRequestsPerChild: 3000
apacheMaxClients: 900

file: group_vars/all

ntp: ntp-boston.example.com
backup: backup-boston.example.com

file: host_vars/db-bos-1.example.com

foo_agent_port: 86
bar_agent_port: 99

file: site.yml

- include: webservers.yml
- include: dbservers.yml

file: webservers.yml

- hosts: webservers
  roles:
    - common
    - webtier

file: roles/common/tasks/main.yml

- name: be sure ntp is installed
  yum: pkg=ntp state=installed
  tags: ntp

- name: be sure ntp is configured
  template: src=ntp.conf.j2 dest=/etc/ntp.conf
  notify:
    - restart ntpd
  tags: ntp

- name: be sure ntpd is running and enabled
  service: name=ntpd state=running enabled=yes
  tags: ntp

file: roles/common/handlers/main.yml

- name: restart ntpd
  service: name=ntpd state=restarted

那这种结构适用于何种应用场景？ 很多！若我想重新配置整个基础设施,如此即可:

ansible-playbook -i production site.yml

那只重新配置所有的 NTP 呢？太容易了.:

ansible-playbook -i production site.yml --tags ntp

只重新配置我的 Web 服务器呢？:

ansible-playbook -i production webservers.yml

只重新配置我在 boston 的 Web服务器呢?:

ansible-playbook -i production webservers.yml --limit boston

前10台和接下来的10台呢？

ansible-playbook -i production webservers.yml –limit boston[0-10]
ansible-playbook -i production webservers.yml –limit boston[10-20]

当然,只使用基础的 ad-hoc 也是 OK 的啦.:

ansible boston -i production -m ping
ansible boston -i production -m command -a '/sbin/reboot'

confirm what task names would be run if I ran this command and said "just ntp tasks"

ansible-playbook -i production webservers.yml --tags ntp --list-tasks

confirm what hostnames might be communicated with if I said "limit to boston"

ansible-playbook -i production webservers.yml --limit boston --list-hosts