Ansible常见特殊模块用法记录

Ansible常见特殊模块用法记录

1、delegate_to：将某一个任务委托给指定主机

- name: "get inventory_hostname" 
  shell: echo {{ inventory_hostname }} $HOSTNAME >>/tmp/test.txt
  delegate_to: "172.18.1.100"

2、connection: local：在本地服务器上运行命令，而不是SSH，可以针对playbook全局使用

- name: "get inventory_hostname" 
  # inventory_hostname为ansible内置变量获取清单中的主机名
  shell: echo {{ inventory_hostname }} $HOSTNAME >>/tmp/test.txt
  connection: local

3、run_once：当前host group中第一个可用host上执行task，可以和delegate_to结合使用

- name: "hello world"
  shell: /bin/sh /root/hello_world.sh
  run_once: true
  delegate_to: "172.18.1.100"

4、ignore_errors：任务失败继续完成剩余的任务

- name: "Delete logs"
  shell: rm -f /var/log/nginx/errors.log
  ignore_errors: true

5、register：保留中间结果，常用于debug

- name: "get host port info" 
  shell: netstat -lntp 
  register: host_port 
- name: "print host port" 
  debug: msg: "{{ host_port['stdout_lines'] }}"

6、until：重试任务直到满足条件

- name: "wait kube-apiserver up"
  shell: "systemctl status kube-apiserver.service |grep Active"
  register: api_status
  until: '"running" in api_status.stdout'
  # 间隔3秒,重试10次
  retries: 10
  delay: 3
  tags: upgrade_k8s, restart_master
---

- name: "wait consul service up"
  uri:
    url: "http://172.18.1.100:8500/ui/"
    method: GET
  register: consul_status
  until: consul_status.status == 200
  retries: 30
  delay: 6

7、when：只在符合when条件的host上执行task

- import_tasks: centos.yml
  when: 'ansible_distribution in ["CentOS","RedHat","Amazon","Aliyun"]' 

8、handlers、notify：触发器

- hosts: all
  tasks:
  - name: "install apache"
    yum: name=httpd state=installed
  - name: "install configure file for httpd"
    copy: src=/root/conf/httpd.conf dest=/etc/httpd/conf/httpd.conf
    notify:
    - restart httpd
    - check httpd
  - name: "start httpd service"
    service: enabled=true name=httpd state=started
  handlers：
  - name: "restart httpd"
    service: name=httpd state=restart
  - name: "check httpd"
    shell: netstat -ntulp |grep 80

9、fail、failed_when、changed_when：中断/改变playbook执行状态

- hosts: all
  tasks: 
  - shell: echo '---error'
    register: return_value
  - fail: 
      msg: 'running fail'
    when: "'error' in return_value.stdout"
  - debug:
      msg: 'I never execute, Because the playbook has stopped'

---
- hosts: all
  tasks:
  - debug:
      msg: "I execute normally"
  - shell: "echo 'This is a string for testing error'"
    register: return_value
    failed_when: ' "error" in return_value.stdout'
  - debug:
      msg: "I never execute,Because the playbook has stopped"

---
- hosts: all
  remote_user: root
  tasks:
  - debug:
      msg: "test message"
    # 可以结合触发器使用
    changed_when: true

10、set_fact：自定义fact变量，可以跨playbook使用

- hosts: all 
  tasks:
    - name: "set_fact"
      set_fact:
        test_fact_1: "{{ ansible_all_ipv6_addresses }}"
        test_fact_2: "{{ ansible_memtotal_mb * 2}}"
    - name: "debug message"
      debug:
        msg: 
        - '{{ test_fact_1 }}'
        - '{{ ansible_memtotal_mb }}'
        - '{{ test_fact_2 }}' 
        - "{{ vars_1 * 2}}"

---
- hosts: all
  tasks:
    - name: "info message"
      debug:
        msg:
        - "{{ test_fact_2 }}"