修正 monitoring.yml 的 check 模式与 Patroni pending 判断

只读探测在 check 模式下照常执行；依赖真实执行结果的等待与验证在 check 模式跳过。
patronictl JSON 会省略空值字段，pending 判断先检查键是否存在。

Co-Authored-By: Claude Opus 5.5 <[email protected]>

infrastructure/shared-postgresql/ansible/monitoring.yml

@@ -23,27 +23,30 @@
   vars:
     pg_patronictl: [/opt/homelab-patroni/bin/patronictl, -c, "{{ pg_config_root }}/prod/patroni.yml"]
   tasks:
+    # JSON 输出会省略空值字段：没有 pending 的成员不带 "Pending restart" 键。
     - name: 读取集群成员状态
       ansible.builtin.command:
-        argv: "{{ pg_patronictl + ['list', '-e', '-f', 'json'] }}"
+        argv: "{{ pg_patronictl + ['list', '-f', 'json'] }}"
       register: pg_members
       changed_when: false
+      check_mode: false
     # Patroni 在原位重启 primary，不触发 failover；写入会短暂中断，客户端需重试。
     - name: 仅重启 pending restart 的成员
       ansible.builtin.command:
         argv: "{{ pg_patronictl + ['restart', 'pg-prod', '--pending', '--force'] }}"
-      when: pg_members.stdout | from_json | selectattr('Pending restart', 'equalto', '*') | list | length > 0
+      when: pg_members.stdout | from_json | selectattr('Pending restart', 'defined') | selectattr('Pending restart', 'equalto', '*') | list | length > 0
       changed_when: true
     - name: 等待两个成员恢复且无 pending
       ansible.builtin.command:
-        argv: "{{ pg_patronictl + ['list', '-e', '-f', 'json'] }}"
+        argv: "{{ pg_patronictl + ['list', '-f', 'json'] }}"
       register: pg_members_after
       changed_when: false
+      when: not ansible_check_mode
       retries: 30
       delay: 4
       until: >-
         (pg_members_after.stdout | from_json | length) == 2
-        and (pg_members_after.stdout | from_json | selectattr('Pending restart', 'equalto', '*') | list | length) == 0
+        and (pg_members_after.stdout | from_json | selectattr('Pending restart', 'defined') | selectattr('Pending restart', 'equalto', '*') | list | length) == 0
         and (pg_members_after.stdout | from_json | selectattr('State', 'in', ['running', 'streaming']) | list | length) == 2
 
 - name: 创建监控角色并安装 exporter
@@ -69,6 +72,8 @@
         dest: /opt
         remote_src: true
         creates: /opt/postgres_exporter-{{ pg_exporter_version }}.linux-amd64/postgres_exporter
+      # check 模式不下载，首次时没有可解压的文件。
+      when: not (ansible_check_mode and pg_exporter_download is changed)
     - name: 逐实例配置
       ansible.builtin.include_tasks: tasks/monitoring-exporter.yml
       loop: "{{ pg_instances }}"

infrastructure/shared-postgresql/ansible/tasks/monitoring-activate.yml

@@ -8,6 +8,7 @@
   ansible.builtin.command:
     argv: [systemctl, is-active, "homelab-postgresql-{{ pg_instance }}.service"]
   changed_when: false
+  check_mode: false
 # 生产：Patroni 只在自身 reload 时把本地配置写成数据目录里的 postgresql.conf/pg_ident.conf，
 # 所以文件视图能说明 Patroni 是否已接收新配置；预加载库是否已生效另看 current_setting。
 # dev：ident_file 是 postmaster 级参数，视图读取的是“当前生效”的那个文件，
@@ -34,6 +35,7 @@
   become: true
   become_user: "{{ pg_profile.user }}"
   changed_when: false
+  check_mode: false
   register: pg_monitor_state
 - name: 让 Patroni 接收新的本地配置（reload，不重启）
   ansible.builtin.command:
@@ -45,7 +47,7 @@
     argv: "{{ pg_monitor_state.cmd }}"
   become: true
   become_user: "{{ pg_profile.user }}"
-  when: pg_instance == 'prod' and pg_monitor_state.stdout.split('|')[0] != 't'
+  when: pg_instance == 'prod' and pg_monitor_state.stdout.split('|')[0] != 't' and not ansible_check_mode
   changed_when: false
   register: pg_monitor_reloaded
   retries: 10
@@ -62,7 +64,7 @@
     argv: "{{ pg_monitor_state.cmd }}"
   become: true
   become_user: "{{ pg_profile.user }}"
-  when: pg_instance == 'dev'
+  when: pg_instance == 'dev' and not ansible_check_mode
   changed_when: false
   register: pg_monitor_dev
   retries: 10

infrastructure/shared-postgresql/ansible/tasks/monitoring-exporter.yml

@@ -22,6 +22,7 @@
   become: true
   become_user: "{{ pg_profile.user }}"
   changed_when: false
+  check_mode: false
   register: pg_monitor_role
 - name: 创建或修正监控角色（无密码，仅能经本地 ident 映射登录）
   ansible.builtin.command:
@@ -49,6 +50,8 @@
     daemon_reload: "{{ pg_exporter_unit is changed }}"
     enabled: true
     state: "{{ 'restarted' if pg_exporter_unit is changed else 'started' }}"
+  # check 模式下 unit 文件尚未写入，systemd 找不到服务。
+  when: not (ansible_check_mode and pg_exporter_unit is changed)
 # 同时证明 HBA/ident 已加载、角色可登录、exporter 能查询。
 - name: 检查 exporter 已连上数据库
   ansible.builtin.uri:
@@ -56,6 +59,7 @@
     return_content: true
   register: pg_exporter_metrics
   changed_when: false
+  when: not ansible_check_mode
   retries: 10
   delay: 3
   until: pg_exporter_metrics.status == 200 and pg_exporter_metrics.content is search('(?m)^pg_up 1$')