【自动化运维神器Ansible】playbook案例解析：Tags组件实现任务选择性执行

• 语法规则：

- name: task_namemodule: parameterstags:- tag1- tag2

---
# tags example
- hosts: websrvsremote_user: rootgather_facts: notasks:- name: Install httpdyum: name=httpd state=present- name: Install configure filecopy: src: files/httpd.conf dest: /etc/httpd/conf/tags: - conf- config- name: start httpd serviceservice: name: httpd state=started enabled=yestags: - service- start

- name: Install httpdyum: name=httpd state=present

• 特点：未指定任何标签
• 执行规则：
  • 使用--tags时会被跳过
  • 使用--skip-tags时会被执行
  • 不指定标签参数时会被执行

- name: Install configure filecopy: src: files/httpd.conf dest: /etc/httpd/conf/tags: - conf- config

• 特点：指定了两个标签（conf和config）
• 执行规则：
  • 当指定-t conf或-t config时会被执行
  • 当指定-t conf,config时也会被执行
  • 当指定-t service时会被跳过

- name: start httpd serviceservice: name: httpd state=started enabled=yestags: - service- start

• 特点：指定了两个标签（service和start）
• 执行规则：
  • 当指定-t service或-t start时会被执行
  • 当指定-t service,start时也会被执行
  • 当指定-t conf时会被跳过

ansible-playbook httpd.yml 
# 分析：所有任务都被执行

ansible-playbook -t conf httpd.yml 
# 分析：只有带有conf标签的任务被执行

ansible-playbook -t conf,service httpd.yml 
# 带有conf或service标签的任务都被执行

ansible-playbook --skip-tags service httpd.yml 
# 分析：跳过了带有service标签的任务

• 场景：复杂Playbook中任务可能属于多个类别

tasks:- name: Deploy web applicationcopy: src=app.war dest=/var/lib/tomcat/webapps/tags:- deploy- web- app- name: Configure databasetemplate: src=db.j2 dest=/etc/app/db.conftags:- config- db- app- name: Restart servicesservice: name={{ item }} state=restartedloop:- tomcat- postgresqltags:- restart- service

• 执行示例：

# 执行所有与应用相关的任务
ansible-playbook -t app deploy.yml# 执行部署和配置任务（跳过重启）
ansible-playbook -t deploy,config deploy.yml# 执行除重启外的所有任务
ansible-playbook --skip-tags restart deploy.yml

• 场景：在角色中定义标签，在Playbook中继承

# roles/common/tasks/main.yml
- name: Update system packagesyum: name=* state=latesttags: system- name: Install common packagesyum: name={{ item }} state=presentloop:- vim- htop- gittags: packages# playbook.yml
- hosts: webserversroles:- commontags:- always

• 场景：基于条件动态添加标签

- name: Install package based on OSyum: name={{ package_name }} state=presentwhen: ansible_os_family == "RedHat"tags: install- name: Configure servicetemplate: src: service.conf.j2 dest: /etc/service/configwhen: service_config_changed is definedtags: config

• 执行示例：

# 仅在RedHat系统上执行安装任务 
ansible-playbook -t install playbook.yml

• 场景：使用标签控制服务重启

tasks:- name: Update configurationcopy: src: config.ini dest: /etc/app/config.initags: confignotify: restart apphandlers:- name: restart appservice: name=app state=restartedtags: restart

• 执行示例：

# 仅执行配置更新并触发重启 
ansible-playbook -t config,restart deploy.yml

---
- hosts: webserversremote_user: rootvars:app_name: "webapp"app_version: "1.2.3"tasks:# 基础环境任务- name: Update system packagesyum: name=* state=latesttags: - system- base- name: Install dependenciesyum: name: - python3- git- nginxstate: presenttags: - packages- base# 应用部署任务- name: Deploy application codegit: repo: https://github.com/example/webapp.gitdest: /opt/{{ app_name }}version: "{{ app_version }}"tags: - deploy- app- name: Deploy configuration filestemplate: src: "{{ item.src }}" dest: "{{ item.dest }}"loop:- { src: app.conf.j2, dest: /etc/{{ app_name }}/app.conf }- { src: nginx.conf.j2, dest: /etc/nginx/conf.d/{{ app_name }}.conf }tags: - config- app# 服务管理任务- name: Start and enable servicesservice: name: "{{ item }}" state: started enabled: yesloop:- nginx- {{ app_name }}tags: - service- start- name: Check service statusservice: name: "{{ item }}" status: yesloop:- nginx- {{ app_name }}tags: - check- statushandlers:- name: Restart applicationservice: name={{ app_name }} state=restartedtags: restart- name: Reload nginxservice: name=nginx state=reloadedtags: reload

ansible-playbook -t base deploy.yml

ansible-playbook -t deploy deploy.yml

ansible-playbook -t base,app,service deploy.yml

ansible-playbook -t check deploy.yml

# 检查标签拼写
ansible-playbook -t conf,service deploy.yml  # 正确
ansible-playbook -t conf,servce deploy.yml   # 错误（拼写错误）# 使用--list-tags查看可用标签
ansible-playbook --list-tags deploy.yml# 检查任务标签定义
grep -n "tags:" deploy.yml

# 使用--tags时包含未标记任务
ansible-playbook --tags all deploy.yml# 或使用--skip-tags排除特定标签
ansible-playbook --skip-tags test deploy.yml

# 使用更具体的标签名称
- name: Deploy frontendcopy: src=frontend dest=/var/www/tags: deploy-frontend- name: Deploy backendcopy: src=backend dest=/var/www/tags: deploy-backend