在AWS EC2实例用Ansible安装MySQL时遇apt缓存更新失败

错误信息 #

failed: [db01] (item=mysql-server) => {"ansible_loop_var": "item", "changed": false, "item": "mysql-server", "msg": "Failed to update apt cache: "}
failed: [db01] (item=mysql-client) => {"ansible_loop_var": "item", "changed": false, "item": "mysql-client", "msg": "Failed to update apt cache: "}
failed: [db01] (item=python-mysqldb) => {"ansible_loop_var": "item", "changed": false, "item": "python-mysqldb", "msg": "Failed to update apt cache: "}
failed: [db01] (item=python3-mysqldb) => {"ansible_loop_var": "item", "changed": false, "item": "python3-mysqldb", "msg": "Failed to update apt cache: "}
failed: [db01] (item=libmysqlclient-dev) => {"ansible_loop_var": "item", "changed": false, "item": "libmysqlclient-dev", "msg": "Failed to update apt cache: "}

我的Ansible Playbook代码 #

---
- name: 配置MySQL（含账号、数据库及远程登录权限）
  hosts: group_vars/dbsrvgrp
  gather_facts: no
  tasks:
    - name: 安装MySQL服务及依赖包
      package:
        name: "{{item}}"
        state: present
        update_cache: yes
        cache_valid_time: 86400
      loop:
        - mysql-server
        - mysql-client
        - python-mysqldb
        - python3-mysqldb
        - libmysqlclient-dev
      ignore_errors: yes
      tags:
        - package

排查与解决方案 #

1. 手动验证APT可用性 #

直接登录db01实例，执行以下命令获取缓存更新失败的具体原因：

sudo apt update

此命令会输出详细错误（如网络不通、源地址失效、权限不足等），是最直接的排查手段。

2. 检查EC2实例网络配置 #

• 确认实例安全组出站规则允许访问公网80/443端口（APT源依赖HTTP/HTTPS获取包信息）
• 测试公网连通性：执行ping google.com或curl http://archive.ubuntu.com验证网络是否正常

3. 修正Playbook配置问题 #

• hosts字段错误：group_vars/dbsrvgrp是变量存储目录，不是Inventory中的主机组名称，需改为实际定义的组名（如dbsrvgrp）
• 移除ignore_errors: yes：该配置会掩盖真实错误，不利于排查，建议暂时删除
• 开启gather_facts：设置gather_facts: yes，让Ansible自动识别目标系统的包管理器和系统信息，避免适配问题

4. 处理APT源失效问题 #

若实例使用的Ubuntu版本过旧（如18.04及更早），官方源已迁移至旧版本归档地址，需修改APT源配置：

1. 备份原有源文件：

   sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak
   

2. 替换源地址为旧版本归档：

   sudo sed -i 's/archive.ubuntu.com/old-releases.ubuntu.com/g' /etc/apt/sources.list
   

3. 再次执行apt update验证缓存更新

内容的提问来源于stack exchange，提问作者etranz