feat(delivery): complete MySQL version-to-package mapping

- 8.0 from Ubuntu archive, 8.4 from MySQL official APT repo
- 5.6/5.7 not supported for now; enforce one MySQL series per host
- Sync Go version whitelist with the playbook package map

ansible/mysql-deploy.yml

@@ -8,9 +8,18 @@
     # --- identity ---
     mysql_instance: "{{ instance_name }}"
     mysql_version_value: "{{ mysql_version | default('8.0') }}"
+    # 版本包映射：8.0 用 Ubuntu 24.04 自带源（精确锁版）；8.4 用 MySQL 官方 APT 源的 LTS 组件
+    # （noble 自带源无 8.4，官方源组件内即为该系列，不再锁小版本）。
+    # 5.6/5.7 已官方 EOL 且 Ubuntu 24.04 无可用 apt 包，明确不纳入白名单。
     mysql_package_map:
-      "8.0": "mysql-server=8.0.46-0ubuntu0.24.04.3"
-    mysql_package_name: "{{ mysql_package_map[mysql_version_value] }}"
+      "8.0":
+        package: "mysql-server=8.0.46-0ubuntu0.24.04.3"
+        repo_component: ""
+      "8.4":
+        package: "mysql-community-server"
+        repo_component: "mysql-8.4-lts"
+    mysql_package_name: "{{ (mysql_package_map[mysql_version_value] | default({})).package | default('') }}"
+    mysql_repo_component: "{{ (mysql_package_map[mysql_version_value] | default({})).repo_component | default('') }}"
 
     # --- platform-allocated inputs (safe fallbacks when not passed in) ---
     # 端口池 13306–13999：平台从池分配并传入；未传时兜底池首端口，占用探测在目标机执行。
@@ -132,13 +141,46 @@
           host-wide Σ-quota budgeting is the platform's responsibility, this is a last-resort guard.
 
   tasks:
-    - name: Detect an existing Ubuntu MySQL package
-      ansible.builtin.command: dpkg-query -W mysql-server
+    - name: Detect an existing MySQL server package
+      ansible.builtin.command: dpkg-query -W -f '${Package}=${Version}\n' mysql-server mysql-community-server
       register: mysql_package_before
       failed_when: false
       changed_when: false
 
-    - name: Install Ubuntu MySQL package
+    - name: Resolve the installed MySQL server version
+      ansible.builtin.set_fact:
+        mysql_installed_version: >-
+          {{ (mysql_package_before.stdout_lines | select('search', '=') | list
+              | first | default('')).split('=') | last }}
+
+    # /usr 下的 mysqld/mysql 二进制全机共享，一台主机只能承载一个 MySQL 版本系列。
+    - name: Enforce host-level MySQL series consistency
+      ansible.builtin.assert:
+        that:
+          - mysql_installed_version == '' or mysql_installed_version.startswith(mysql_version_value ~ '.')
+        fail_msg: >-
+          Host already runs MySQL {{ mysql_installed_version }} but {{ mysql_version_value }} was requested;
+          native binaries under /usr are shared host-wide, so one host serves exactly one MySQL series.
+
+    - name: Install the MySQL APT repository signing key
+      ansible.builtin.get_url:
+        url: https://repo.mysql.com/RPM-GPG-KEY-mysql-2023
+        dest: /etc/apt/keyrings/mysql.asc
+        owner: root
+        group: root
+        mode: '0644'
+      when: mysql_repo_component != ''
+
+    - name: Configure the MySQL APT repository component
+      ansible.builtin.apt_repository:
+        repo: >-
+          deb [signed-by=/etc/apt/keyrings/mysql.asc]
+          http://repo.mysql.com/apt/ubuntu {{ ansible_distribution_release }} {{ mysql_repo_component }}
+        filename: xinfra-mysql-delivery
+        state: present
+      when: mysql_repo_component != ''
+
+    - name: Install the MySQL server package
       ansible.builtin.apt:
         name: "{{ mysql_package_name }}"
         state: present
@@ -150,7 +192,7 @@
         name: mysql.service
         state: stopped
         enabled: false
-      when: mysql_package_before.rc != 0
+      when: mysql_installed_version == ''
 
     - name: Check for the bundled MySQL AppArmor profile
       ansible.builtin.stat: