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/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$')