feat: добавить Prometheus-метрики для nfs-server addon

- Устанавливает prometheus-node-exporter на NFS-хостах (включает NFSD-коллектор из /proc/net/rpc/nfsd)
- Открывает порт 9100 в UFW для cluster-сети
- При addon_prometheus_stack=true создаёт в k8s:
  - headless Service nfs-server-node-exporter
  - Endpoints со списком IP NFS-хостов из inventory
  - ServiceMonitor с label release: kube-prometheus-stack

addons/nfs-server/role/defaults/main.yml

@@ -19,3 +19,9 @@ nfs_create_export_dirs: true
 nfs_export_dir_mode: "0777"
 nfs_export_dir_owner: "nobody"
 nfs_export_dir_group: "nogroup"
+
+# ── Метрики (node_exporter с NFSD-коллектором) ───────────────────────────────
+nfs_metrics_enabled: true
+nfs_metrics_port: 9100
+# Namespace в k8s для ServiceMonitor/Endpoints (должен существовать)
+nfs_metrics_namespace: "monitoring"

addons/nfs-server/role/tasks/main.yml

@@ -47,6 +47,109 @@
   become: true
   failed_when: false  # UFW может быть не установлен
 
+- name: Install prometheus-node-exporter for NFS metrics
+  ansible.builtin.apt:
+    name: prometheus-node-exporter
+    state: present
+  become: true
+  when: nfs_metrics_enabled | bool
+
+- name: Enable and start prometheus-node-exporter
+  ansible.builtin.systemd:
+    name: prometheus-node-exporter
+    enabled: true
+    state: started
+  become: true
+  when: nfs_metrics_enabled | bool
+
+- name: Allow node-exporter port through UFW (if active)
+  community.general.ufw:
+    rule: allow
+    src: "{{ nfs_allowed_network }}"
+    port: "{{ nfs_metrics_port }}"
+    proto: tcp
+  become: true
+  failed_when: false
+  when: nfs_metrics_enabled | bool
+
+- name: Build NFS host IP list for Endpoints
+  ansible.builtin.set_fact:
+    _nfs_endpoints_addresses: "{{ (_nfs_endpoints_addresses | default([])) + [{'ip': hostvars[item]['ansible_default_ipv4']['address']}] }}"
+  loop: "{{ groups['nfs_server'] }}"
+  run_once: true
+  when: nfs_metrics_enabled | bool and addon_prometheus_stack | default(false) | bool
+
+- name: Create headless Service for NFS node-exporter
+  kubernetes.core.k8s:
+    state: present
+    definition:
+      apiVersion: v1
+      kind: Service
+      metadata:
+        name: nfs-server-node-exporter
+        namespace: "{{ nfs_metrics_namespace }}"
+        labels:
+          app: nfs-server-node-exporter
+      spec:
+        clusterIP: None
+        ports:
+          - name: metrics
+            port: "{{ nfs_metrics_port }}"
+            targetPort: "{{ nfs_metrics_port }}"
+  delegate_to: "{{ groups['k3s_master'][0] }}"
+  run_once: true
+  become: true
+  environment:
+    KUBECONFIG: "{{ k3s_kubeconfig_path }}"
+  when: nfs_metrics_enabled | bool and addon_prometheus_stack | default(false) | bool
+
+- name: Create Endpoints for NFS node-exporter
+  kubernetes.core.k8s:
+    state: present
+    definition:
+      apiVersion: v1
+      kind: Endpoints
+      metadata:
+        name: nfs-server-node-exporter
+        namespace: "{{ nfs_metrics_namespace }}"
+      subsets:
+        - addresses: "{{ _nfs_endpoints_addresses }}"
+          ports:
+            - name: metrics
+              port: "{{ nfs_metrics_port }}"
+  delegate_to: "{{ groups['k3s_master'][0] }}"
+  run_once: true
+  become: true
+  environment:
+    KUBECONFIG: "{{ k3s_kubeconfig_path }}"
+  when: nfs_metrics_enabled | bool and addon_prometheus_stack | default(false) | bool
+
+- name: Create ServiceMonitor for NFS node-exporter
+  kubernetes.core.k8s:
+    state: present
+    definition:
+      apiVersion: monitoring.coreos.com/v1
+      kind: ServiceMonitor
+      metadata:
+        name: nfs-server-node-exporter
+        namespace: "{{ nfs_metrics_namespace }}"
+        labels:
+          release: kube-prometheus-stack
+      spec:
+        selector:
+          matchLabels:
+            app: nfs-server-node-exporter
+        endpoints:
+          - port: metrics
+            path: /metrics
+            interval: 30s
+  delegate_to: "{{ groups['k3s_master'][0] }}"
+  run_once: true
+  become: true
+  environment:
+    KUBECONFIG: "{{ k3s_kubeconfig_path }}"
+  when: nfs_metrics_enabled | bool and addon_prometheus_stack | default(false) | bool
+
 - name: Verify NFS exports are active
   ansible.builtin.command: exportfs -v
   register: nfs_exportfs