Ansible的Playbooks是Ansible用于配置，部署应用的结构化语言。Ansible的模块就好比shell命令，那么playbooks就好比shell脚本，在脚本中指定怎么使用哪些命令再加上一些判断语句等等。
Playbooks使用YAML文件来表示执行步骤。
--- - hosts: webservers vars: http_port: 80 max_clients: 200 remote_user: root tasks: - name: ensure apache is at the latest version yum: name=httpd state=latest - name: write the apache config file template: src=/srv/httpd.j2 dest=/etc/httpd.conf notify: - restart apache - name: ensure apache is running (and enable it at boot) service: name=httpd state=started enabled=yes handlers: - name: restart apache service: name=httpd state=restarted
也可以写成这样：
--- - hosts: webservers vars: http_port: 80 max_clients: 200 remote_user: root tasks: - name: ensure apache is at the latest version yum: name: httpd state: latest - name: write the apache config file template: src: /srv/httpd.j2 dest: /etc/httpd.conf notify: - restart apache - name: ensure apache is running service: name: httpd state: started handlers: - name: restart apache service: name: httpd state: restarted
Playbooks中也可以包含多个plays。
--- - hosts: webservers remote_user: root tasks: - name: ensure apache is at the latest version yum: name=httpd state=latest - name: write the apache config file template: src=/srv/httpd.j2 dest=/etc/httpd.conf - hosts: databases remote_user: root tasks: - name: ensure postgresql is at the latest version yum: name=postgresql state=latest - name: ensure that postgresql is started service: name=postgresql state=running
hosts 行指定匹配的主机组或者主机，以逗号","分隔
remote_user 指定远程执行task步骤的用户
remote_user在Ansible1.4之前被叫做user
也可以为每个task单独指定远程执行用户
--- - hosts: webservers remote_user: root tasks: - name: test connection ping: remote_user: yourname
使用提权用户执行
--- - hosts: webservers remote_user: yourname become: yes
为单个task指定become
--- - hosts: webservers remote_user: yourname tasks: - service: name=nginx state=started become: yes become_method: sudo
以自身用户登录然后以root意外的用户执行
--- - hosts: webservers remote_user: yourname become: yes become_user: postgres
--- - hosts: webservers remote_user: yourname become: yes become_method: su
任务列表 Task lists
tasks: - name: make sure apache is running service: name=httpd state=running
每个play都包含了一系列tasks。command和shell模块可以只带几个参数，不必写成key=value的形式
tasks: - name: disable selinux command: /sbin/setenforce 0
每个需要执行的task都必须要有一个name用于表示执行步骤
command和shell模块关系返回码，如果有命令执行成功退出码不是0，可以这样：
tasks: - name: run this command and ignore the result shell: /usr/bin/somecommand || /bin/true
或者：
tasks: - name: run this command and ignore the result shell: /usr/bin/somecommand ignore_errors: True
如果执行行太长可以分行写：
tasks: - name: Copy ansible inventory file to client copy: src=/etc/ansible/hosts dest=/etc/ansible/hosts owner=root group=root mode=0644
执行可以使用变量。假设定义了一个vhost的变量：
tasks:
- name: create a virtual host file for {{ vhost }}
template: src=somefile.j2 dest=/etc/httpd/conf.d/{{ vhost }}
Handlers： Running Operations On Change
- name: template configuration file template: src=template.j2 dest=/etc/foo.conf notify: - restart memcached - restart apache
notify行列出的区域就叫做handlers
Handlers are lists of tasks,not really any different from regular tasks,that are refercenced by a globaly unique name.Handlers are what notifiers notify.
如果没有通知handler,notify区域将不会执行。
handlers: - name: restart memcached service: name=memcached state=restarted - name: restart apache service: name=apache state=restarted
Handlers最适用于重启服务和触发重启服务。
执行playbook
# ansible-playbook -i ansible_hosts install_apache.yml -f 10
执行playbook之前最好检查下有哪些主机会被执行，防止误操作
# ansible-playbook -i ansible_hosts install_apache.yml -f 10 --list-hosts
ansible-pull
ansible默认是以push的方式工作，即ansible主动推送执行任务给各个节点。也可以使用pull的方式，让各个节点从中心拉取配置然然后执行。
Playbooks Roles and Include Statements
假设想要在多个plays或者playbooks之间重用tasks，可以使用include
---# possibly saved as tasks/foo.yml - name: placeholder foo command: /bin/foo - name: placeholder bar command: /bin/bar
include 指令可以这样使用
tasks: - include: tasks/foo.yml
还可以给include传递参数
tasks: - include: wordpress.yml wp_user=timmy - include: wordpress.yml wp_user=alice - include: wordpress.yml wp_user=bob
也可以这样：
tasks: - include: wordpress.yml vars: wp_user: timmy ssh_keys: - keys/one.txt - keys/two.txt
传递的变量可以在被包含的文件中使用，使用变量的方式如下：
{{ wp_user }}
参考文档：
http://docs.ansible.com/ansible/playbooks.html
https://github.com/ansible/ansible-examples/blob/master/windows/deploy-site.yml
http://docs.ansible.com/ansible/intro_patterns.html