ansible

Ansible 自动化运维

概述

Playbook 编写、角色管理、动态 inventory 等技能。

基础命令

Ad-hoc 命令

# 测试连通性
ansible all -m ping
ansible webservers -m ping

# 执行命令
ansible all -m command -a "uptime"
ansible all -m shell -a "df -h | grep /dev"

# 复制文件
ansible all -m copy -a "src=/local/file dest=/remote/file"

# 安装软件
ansible all -m apt -a "name=nginx state=present" --become
ansible all -m yum -a "name=nginx state=present" --become

# 管理服务
ansible all -m service -a "name=nginx state=started" --become

# 收集信息
ansible all -m setup
ansible all -m setup -a "filter=ansible_distribution*"

常用参数

-i inventory          # 指定 inventory
-m module             # 指定模块
-a arguments          # 模块参数
-b, --become          # 提权
-K                    # 询问 sudo 密码
-u user               # 指定用户
-k                    # 询问 SSH 密码
--limit host          # 限制主机
-v, -vv, -vvv         # 详细输出
--check               # 检查模式（不执行）
--diff                # 显示差异

Inventory

静态 inventory

# inventory/hosts
[webservers]
web1.example.com
web2.example.com ansible_host=192.168.1.10

[dbservers]
db1.example.com ansible_user=admin
db2.example.com

[production:children]
webservers
dbservers

[all:vars]
ansible_python_interpreter=/usr/bin/python3

YAML 格式

# inventory/hosts.yml
all:
  children:
    webservers:
      hosts:
        web1.example.com:
        web2.example.com:
          ansible_host: 192.168.1.10
    dbservers:
      hosts:
        db1.example.com:
          ansible_user: admin
  vars:
    ansible_python_interpreter: /usr/bin/python3

动态 inventory

# 使用脚本
ansible-inventory -i inventory.py --list

# AWS EC2
ansible-inventory -i aws_ec2.yml --list

# 示例 aws_ec2.yml
plugin: amazon.aws.aws_ec2
regions:
  - us-east-1
filters:
  tag:Environment: production
keyed_groups:
  - key: tags.Role
    prefix: role

Playbook

基础结构

# playbook.yml
---
- name: Configure web servers
  hosts: webservers
  become: yes
  vars:
    http_port: 80
    
  tasks:
    - name: Install nginx
      apt:
        name: nginx
        state: present
        update_cache: yes
      
    - name: Start nginx
      service:
        name: nginx
        state: started
        enabled: yes
        
    - name: Copy config
      template:
        src: nginx.conf.j2
        dest: /etc/nginx/nginx.conf
      notify: Restart nginx
      
  handlers:
    - name: Restart nginx
      service:
        name: nginx
        state: restarted