feat(admin/metrics): add Prometheus-compatible metrics endpoint and ops documentation

- Add /api/metrics/prometheus endpoint using prom-client (unauthenticated for scraping)
- Update middleware to allow unauthenticated access to prometheus endpoint
- Add /api/metrics permission routing (platform:read for GET)
- Install prom-client dependency
- Add metrics.md with Grafana dashboard JSON, Prometheus config, alerting rules

admin/metrics.md

@@ -0,0 +1,278 @@
+# Admin 平台指标 — Grafana / Prometheus 配置指南
+
+## 概述
+
+Admin 服务暴露两个指标端点：
+
+| 端点 | 格式 | 用途 |
+|------|------|------|
+| `GET /api/metrics` | JSON | 前端页面 / 人工查看 / API 消费 |
+| `GET /api/metrics/prometheus` | Prometheus Text | Prometheus 采集 |
+
+Prometheus 端点 **无需认证**，可直接 scrape。
+
+## 采集的指标
+
+所有指标通过 `platform_entity_count` Gauge 暴露，带 `entity` 和 `window` 两个 label：
+
+```
+# HELP platform_entity_count Platform entity counts by time window
+# TYPE platform_entity_count gauge
+platform_entity_count{entity="users",window="total"} 1000
+platform_entity_count{entity="users",window="27h"} 5
+platform_entity_count{entity="users",window="7d"} 32
+platform_entity_count{entity="users",window="30d"} 150
+platform_entity_count{entity="workspaces",window="total"} 50
+platform_entity_count{entity="workspaces",window="27h"} 1
+...
+platform_entity_count{entity="skills",window="30d"} 45
+```
+
+Entity 列表：`users`、`workspaces`、`projects`、`repos`、`rooms`、`skills`
+
+Window 列表：`total`（累计）、`27h`（近27小时）、`7d`（近7天）、`30d`（近30天）
+
+## Prometheus 配置
+
+### prometheus.yml
+
+```yaml
+scrape_configs:
+  - job_name: 'admin-metrics'
+    scrape_interval: 60s
+    metrics_path: '/api/metrics/prometheus'
+    static_configs:
+      - targets: ['<admin-host>:<port>']
+        labels:
+          env: 'production'
+          service: 'admin'
+```
+
+### K8s ServiceMonitor（如果用 prometheus-operator）
+
+```yaml
+apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+  name: admin-metrics
+  namespace: monitoring
+  labels:
+    release: prometheus
+spec:
+  selector:
+    matchLabels:
+      app: admin
+  endpoints:
+    - port: http
+      path: /api/metrics/prometheus
+      interval: 60s
+```
+
+## Grafana Dashboard
+
+### 推荐 Panel 配置
+
+#### Panel 1: 实体总量（Stat Panel）
+
+```
+Query:
+  platform_entity_count{window="total"}
+
+Visualization: Stat
+  - Show: Value
+  - Color mode: Background
+  - Thresholds: 按实际业务设定
+```
+
+#### Panel 2: 27 小时增长趋势（Time Series / Bar Gauge）
+
+```
+Query:
+  platform_entity_count{window="27h"}
+
+Visualization: Bar Gauge
+  - Display: Basic
+  - Show: Value
+```
+
+#### Panel 3: 7 天 / 30 天对比（Bar Chart）
+
+```
+Query:
+  platform_entity_count{window=~"7d|30d"}
+
+Visualization: Bar Chart
+  - Group by: entity
+  - Bar mode: grouped
+```
+
+#### Panel 4: 总量汇总表（Table Panel）
+
+```
+Query:
+  platform_entity_count
+
+Transform:
+  1. Labels to fields
+  2. Pivot by entity
+  3. Organize fields
+
+Visualization: Table
+```
+
+### Dashboard JSON 模板
+
+将以下 JSON 导入 Grafana（Dashboard → Import → Paste JSON）：
+
+> 注：`uid` 和 `datasource` 需要根据实际 Prometheus 数据源修改。
+
+```json
+{
+  "dashboard": {
+    "title": "Admin 平台指标",
+    "tags": ["admin", "platform"],
+    "timezone": "browser",
+    "panels": [
+      {
+        "id": 1,
+        "title": "实体总量",
+        "type": "stat",
+        "gridPos": { "h": 4, "w": 24, "x": 0, "y": 0 },
+        "targets": [
+          {
+            "expr": "platform_entity_count{window=\"total\"}",
+            "legendFormat": "{{entity}}"
+          }
+        ],
+        "options": {
+          "colorMode": "background",
+          "graphMode": "none",
+          "justifyMode": "auto"
+        },
+        "fieldConfig": {
+          "defaults": {
+            "thresholds": {
+              "mode": "absolute",
+              "steps": [
+                { "color": "green", "value": null },
+                { "color": "yellow", "value": 100 },
+                { "color": "red", "value": 1000 }
+              ]
+            }
+          }
+        }
+      },
+      {
+        "id": 2,
+        "title": "近 27 小时新增",
+        "type": "bargauge",
+        "gridPos": { "h": 6, "w": 12, "x": 0, "y": 4 },
+        "targets": [
+          {
+            "expr": "platform_entity_count{window=\"27h\"}",
+            "legendFormat": "{{entity}}"
+          }
+        ],
+        "options": {
+          "displayMode": "gradient",
+          "orientation": "horizontal"
+        }
+      },
+      {
+        "id": 3,
+        "title": "近 7 天 / 30 天对比",
+        "type": "barchart",
+        "gridPos": { "h": 6, "w": 12, "x": 12, "y": 4 },
+        "targets": [
+          {
+            "expr": "platform_entity_count{window=~\"7d|30d\"}",
+            "legendFormat": "{{entity}} ({{window}})"
+          }
+        ],
+        "options": {
+          "barRadius": 0.05,
+          "groupWidth": 0.7,
+          "orientation": "auto"
+        }
+      },
+      {
+        "id": 4,
+        "title": "指标汇总表",
+        "type": "table",
+        "gridPos": { "h": 8, "w": 24, "x": 0, "y": 10 },
+        "targets": [
+          {
+            "expr": "platform_entity_count",
+            "format": "table",
+            "instant": true
+          }
+        ],
+        "transformations": [
+          { "id": "labelsToFields", "options": {} },
+          {
+            "id": "organize",
+            "options": {
+              "excludeByName": { "Time": true, "__name__": true },
+              "indexByName": { "entity": 0, "window": 1, "Value": 2 }
+            }
+          }
+        ],
+        "options": {
+          "showHeader": true,
+          "sortBy": [{ "desc": false, "displayName": "entity" }]
+        }
+      }
+    ],
+    "time": { "from": "now-24h", "to": "now" },
+    "refresh": "1m"
+  },
+  "overwrite": true
+}
+```
+
+## 告警规则（可选）
+
+### prometheus rules
+
+```yaml
+groups:
+  - name: admin-entity-growth
+    rules:
+      # 27 小时内用户增长超过 100 告警
+      - alert: HighUserGrowth27h
+        expr: platform_entity_count{entity="users", window="27h"} > 100
+        for: 5m
+        labels:
+          severity: warning
+        annotations:
+          summary: "27 小时内新增用户 {{ $value }} 超过阈值"
+
+      # 仓库 7 天零增长告警
+      - alert: NoRepoGrowth7d
+        expr: platform_entity_count{entity="repos", window="7d"} == 0
+          and on() platform_entity_count{entity="repos", window="total"} > 0
+        for: 1h
+        labels:
+          severity: info
+        annotations:
+          summary: "近 7 天无新增仓库"
+```
+
+## 验证
+
+```bash
+# 1. JSON 格式
+curl http://localhost:3000/api/metrics | jq .
+
+# 2. Prometheus 格式
+curl http://localhost:3000/api/metrics/prometheus
+
+# 预期输出:
+# HELP platform_entity_count Platform entity counts by time window
+# TYPE platform_entity_count gauge
+platform_entity_count{entity="users",window="27h"} 0
+platform_entity_count{entity="users",window="30d"} 0
+platform_entity_count{entity="users",window="7d"} 0
+platform_entity_count{entity="users",window="total"} 5
+...
+```

admin/package-lock.json

@@ -21,6 +21,7 @@
         "next": "16.2.4",
         "node-cron": "^4.2.1",
         "pg": "^8.11.3",
+        "prom-client": "^15.1.3",
         "react": "19.2.4",
         "react-dom": "19.2.4",
         "tailwind-merge": "^2.2.0",
@@ -1677,6 +1678,15 @@
         "node": ">=12.4.0"
       }
     },
+    "node_modules/@opentelemetry/api": {
+      "version": "1.9.1",
+      "resolved": "https://registry.npmmirror.com/@opentelemetry/api/-/api-1.9.1.tgz",
+      "integrity": "sha512-gLyJlPHPZYdAk1JENA9LeHejZe1Ti77/pTeFm/nMXmQH/HFZlcS/O2XJB+L8fkbrNSqhdtlvjBVjxwUYanNH5Q==",
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=8.0.0"
+      }
+    },
     "node_modules/@phc/format": {
       "version": "1.0.0",
       "resolved": "https://registry.npmmirror.com/@phc/format/-/format-1.0.0.tgz",
@@ -2964,6 +2974,12 @@
         "node": ">= 10.0.0"
       }
     },
+    "node_modules/bintrees": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmmirror.com/bintrees/-/bintrees-1.0.2.tgz",
+      "integrity": "sha512-VOMgTMwjAaUG580SXn3LacVgjurrbMme7ZZNYGSSV7mmtY6QQRh0Eg3pwIcntQ77DErK1L0NxkbetjcoXzVwKw==",
+      "license": "MIT"
+    },
     "node_modules/brace-expansion": {
       "version": "1.1.14",
       "license": "MIT",
@@ -6082,6 +6098,19 @@
         "node": ">= 0.8.0"
       }
     },
+    "node_modules/prom-client": {
+      "version": "15.1.3",
+      "resolved": "https://registry.npmmirror.com/prom-client/-/prom-client-15.1.3.tgz",
+      "integrity": "sha512-6ZiOBfCywsD4k1BN9IX0uZhF+tJkV8q8llP64G5Hajs4JOeVLPCwpPVcpXy3BwYiUGgyJzsJJQeOIv7+hDSq8g==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@opentelemetry/api": "^1.4.0",
+        "tdigest": "^0.1.1"
+      },
+      "engines": {
+        "node": "^16 || ^18 || >=20"
+      }
+    },
     "node_modules/prop-types": {
       "version": "15.8.1",
       "dev": true,
@@ -6835,6 +6864,15 @@
       "version": "4.0.0",
       "license": "ISC"
     },
+    "node_modules/tdigest": {
+      "version": "0.1.2",
+      "resolved": "https://registry.npmmirror.com/tdigest/-/tdigest-0.1.2.tgz",
+      "integrity": "sha512-+G0LLgjjo9BZX2MfdvPfH+MKLCrxlXSYec5DaPYP1fe6Iyhf0/fSmJ0bFiZ1F8BT6cGXl2LpltQptzjXKWEkKA==",
+      "license": "MIT",
+      "dependencies": {
+        "bintrees": "1.0.2"
+      }
+    },
     "node_modules/tinyglobby": {
       "version": "0.2.16",
       "dev": true,

admin/package.json

@@ -26,6 +26,7 @@
     "next": "16.2.4",
     "node-cron": "^4.2.1",
     "pg": "^8.11.3",
+    "prom-client": "^15.1.3",
     "react": "19.2.4",
     "react-dom": "19.2.4",
     "tailwind-merge": "^2.2.0",

admin/src/app/api/metrics/prometheus/route.ts

@@ -0,0 +1,74 @@
+import { NextResponse } from "next/server";
+import { Registry, Gauge } from "prom-client";
+import { query } from "@/lib/db";
+
+export const runtime = "nodejs";
+
+/**
+ * Prometheus-compatible metrics endpoint.
+ *
+ * Usage in prometheus.yml:
+ *   - job_name: 'admin-metrics'
+ *     scrape_interval: 60s
+ *     static_configs:
+ *       - targets: ['admin:3000']
+ *     metrics_path: '/api/metrics/prometheus'
+ */
+export async function GET() {
+  const register = new Registry();
+
+  const gauge = new Gauge({
+    name: "platform_entity_count",
+    help: "Platform entity counts by time window",
+    labelNames: ["entity", "window"] as const,
+    registers: [register],
+  });
+
+  const entities = [
+    { name: "users", table: '"user"' },
+    { name: "workspaces", table: "workspace" },
+    { name: "projects", table: "project" },
+    { name: "repos", table: "repo" },
+    { name: "rooms", table: "room" },
+    { name: "skills", table: "project_skill" },
+  ];
+
+  const results = await Promise.all(
+    entities.map(async ({ name, table }) => {
+      const res = await query<{
+        total: string;
+        new_27h: string;
+        new_7d: string;
+        new_30d: string;
+      }>(
+        `SELECT
+          COUNT(*) AS total,
+          COUNT(*) FILTER (WHERE created_at >= NOW() - INTERVAL '27 hours') AS new_27h,
+          COUNT(*) FILTER (WHERE created_at >= NOW() - INTERVAL '7 days') AS new_7d,
+          COUNT(*) FILTER (WHERE created_at >= NOW() - INTERVAL '30 days') AS new_30d
+         FROM ${table}`
+      );
+      const row = res.rows[0];
+      return {
+        name,
+        total: parseInt(row.total, 10),
+        new_27h: parseInt(row.new_27h, 10),
+        new_7d: parseInt(row.new_7d, 10),
+        new_30d: parseInt(row.new_30d, 10),
+      };
+    })
+  );
+
+  for (const r of results) {
+    gauge.set({ entity: r.name, window: "total" }, r.total);
+    gauge.set({ entity: r.name, window: "27h" }, r.new_27h);
+    gauge.set({ entity: r.name, window: "7d" }, r.new_7d);
+    gauge.set({ entity: r.name, window: "30d" }, r.new_30d);
+  }
+
+  const metrics = await register.metrics();
+
+  return new NextResponse(metrics, {
+    headers: { "Content-Type": register.contentType },
+  });
+}

admin/src/middleware.ts

@@ -12,7 +12,7 @@ import { createHash } from "crypto";
 import { parseSessionCookie, loadAdminSession, canAccess } from "@/lib/auth";
 import { query } from "@/lib/db";
 
-const PUBLIC_PATHS = ["/login", "/api/auth/login", "/api/auth/oidc", "/api/health"];
+const PUBLIC_PATHS = ["/login", "/api/auth/login", "/api/auth/oidc", "/api/health", "/api/metrics/prometheus"];
 const PROTECTED_PATHS = ["/dashboard", "/admin", "/platform"];
 
 function getRequiredPermission(path: string, method: string): string | null {