feat: add cron engine with TTL triggers, Redis CLI, and 6-field cron support

README.md

@@ -0,0 +1,242 @@
+# PulseBoard — Embr Cache Template
+
+A real-time dashboard showcasing Embr Cache (Valkey/Redis) features. Deploy it to [Embr](https://portal.embr.azure) with a single command and explore caching patterns through an interactive UI.
+
+## Quick Start
+
+```bash
+embr login
+embr quickstart deploy <owner>/embr-cache-template
+```
+
+Once deployed, open the environment URL shown in the output.
+
+---
+
+## Features
+
+### 1. Leaderboard (Sorted Sets)
+
+A ranked player leaderboard powered by Redis sorted sets (`ZADD`, `ZREVRANGE`, `ZINCRBY`).
+
+- Add players with scores
+- Boost scores with random increments
+- Remove players
+- Auto-refreshes every 3 seconds
+
+### 2. Atomic Counters (INCR / SET)
+
+Live counters for page views, API calls, cache hits, and errors using Redis `INCR` and `SET`.
+
+- Increment any counter with one click
+- Reset counters to zero
+- Seeded with demo data on first run
+
+### 3. Cache Explorer (GET / SETEX / TTL)
+
+Set key-value pairs with a TTL and watch them expire in real time.
+
+- **SET** a key with a value and TTL (1–3600 seconds, default 60)
+- **GET** a key to see cache hit/miss status and remaining TTL
+- Browse all live `demo:*` keys with their values and countdowns
+- Flush all demo keys at once
+- Auto-refreshes every 5 seconds
+
+### 4. Cron Engine (TTL Triggers)
+
+A cron job scheduler that uses **Valkey key expiration as the trigger mechanism** — no external scheduler needed.
+
+**How it works:**
+
+1. You create a job with a cron expression (e.g., `*/5 * * * *`) and an action
+2. The server parses the cron expression and calculates seconds until the next fire
+3. A Redis key (`cron:trigger:{id}`) is set with that TTL via `SETEX`
+4. When the key expires, Valkey publishes a [keyspace notification](https://redis.io/docs/manual/keyspace-notifications/)
+5. A dedicated subscriber connection receives the event and executes the job
+6. The trigger key is immediately recreated with the TTL for the next cron match
+
+**Supported actions:**
+
+| Type | Description | Example |
+|------|-------------|---------|
+| HTTP | Makes a GET request to a URL | `https://example.com/webhook` |
+| Script | Executes a shell command | `echo "hello"` |
+
+**UI features:**
+
+- Preset schedules (every minute, 5 min, 15 min, hourly, daily) or custom cron expressions
+- Pause / resume individual jobs
+- View execution logs with timestamp, duration, and success/failure status
+- Delete jobs
+
+**Cron expression format:** `minute hour day-of-month month day-of-week`
+
+Supports `*`, ranges (`1-5`), steps (`*/5`), and lists (`1,3,5`).
+
+### 5. Redis CLI (Interactive)
+
+A terminal-style Redis client embedded in the browser.
+
+- Execute any Redis command directly (e.g., `PING`, `KEYS *`, `INFO server`, `HGETALL cron:job:...`)
+- Arrow-key command history (up/down)
+- Type `CLEAR` to reset the output panel
+- Dangerous commands are blocked server-side (`FLUSHALL`, `SHUTDOWN`, `CONFIG`, etc.)
+
+---
+
+## Cache Modes
+
+Embr Cache supports two modes, configured in `embr.yaml`:
+
+### Embedded Mode
+
+```yaml
+cache:
+  enabled: true
+  mode: "embedded"
+  maxMemory: 128
+  evictionPolicy: "allkeys-lru"
+```
+
+- Valkey runs **inside** your application's sandbox
+- Connected via `redis://127.0.0.1:6379`
+- Data is local to the instance — not shared across scaled instances
+- Fastest latency (loopback network)
+- Good for: single-instance apps, caching, development
+
+### Managed Mode
+
+```yaml
+cache:
+  enabled: true
+  mode: "managed"
+  maxMemory: 128
+  evictionPolicy: "allkeys-lru"
+```
+
+- Valkey runs as a **separate managed service** provisioned by Embr
+- Connected via a network endpoint (connection URL provided by the platform)
+- Data is **shared across all instances** of the environment
+- Survives instance restarts and redeployments
+- Good for: multi-instance apps, shared state, production workloads
+
+### Switching Modes
+
+1. Edit `embr.yaml` and change `mode` to `"embedded"` or `"managed"`
+2. Commit and push — Embr will redeploy with the new cache configuration
+3. If switching to managed, Embr provisions a new cache instance during deployment (adds ~20s to deploy)
+
+> **Note:** Switching modes creates a fresh cache — existing data does not migrate between modes.
+
+---
+
+## Configuration Reference
+
+### `embr.yaml`
+
+```yaml
+platform: nodejs
+platformVersion: "20"
+autoDeploy: true
+
+run:
+  port: 3000
+  startCommand: node server/index.js
+
+cache:
+  enabled: true
+  mode: "managed"          # "embedded" or "managed"
+  maxMemory: 128           # Max memory in MB
+  evictionPolicy: "allkeys-lru"  # Valkey eviction policy
+
+static:
+  spaFallback: true
+  headers:
+    "*.js": "public, max-age=31536000, immutable"
+    "*.css": "public, max-age=31536000, immutable"
+
+healthCheck:
+  path: /health
+```
+
+### Cache Options
+
+| Option | Values | Description |
+|--------|--------|-------------|
+| `enabled` | `true` / `false` | Enable or disable the cache |
+| `mode` | `"embedded"` / `"managed"` | Cache deployment mode (see above) |
+| `maxMemory` | Integer (MB) | Maximum memory allocation |
+| `evictionPolicy` | `allkeys-lru`, `volatile-lru`, `noeviction`, etc. | What happens when memory is full |
+
+### Environment Variable
+
+| Variable | Default | Description |
+|----------|---------|-------------|
+| `REDIS_URL` | `redis://127.0.0.1:6379` | Redis/Valkey connection URL (auto-set by Embr) |
+
+---
+
+## Project Structure
+
+```
+├── embr.yaml                 # Embr deployment configuration
+├── package.json
+├── vite.config.js             # Vite build config with API proxy
+├── client/
+│   ├── index.html
+│   └── src/
+│       ├── main.jsx           # React entry point
+│       ├── App.jsx            # Main app: Counters, Leaderboard, CacheExplorer
+│       ├── CronJobs.jsx       # Cron engine UI
+│       ├── RedisCli.jsx       # Interactive Redis CLI
+│       └── styles.css
+└── server/
+    ├── index.js               # Express server entry point
+    ├── cache/
+    │   └── index.js           # Redis connections (primary + subscriber)
+    ├── cron/
+    │   ├── parser.js          # 5-field cron expression parser
+    │   └── engine.js          # Keyspace notification listener + job executor
+    ├── middleware/
+    │   └── errorHandler.js
+    └── routes/
+        ├── health.js
+        ├── leaderboard.js     # Sorted set operations
+        ├── counters.js        # Atomic counter operations
+        ├── cacheDemo.js       # GET/SETEX/TTL demo
+        ├── cron.js            # Cron job CRUD API
+        ├── redisCli.js        # Redis CLI API (safe command execution)
+        └── stats.js           # Redis server stats
+```
+
+---
+
+## API Endpoints
+
+| Method | Path | Description |
+|--------|------|-------------|
+| GET | `/health` | Health check |
+| GET | `/api/stats` | Redis server memory and connection stats |
+| GET/POST | `/api/leaderboard` | List / add players |
+| POST | `/api/leaderboard/:name/increment` | Boost a player's score |
+| DELETE | `/api/leaderboard/:name` | Remove a player |
+| GET/POST | `/api/counters` | List / manage counters |
+| POST | `/api/cache-demo/set` | Set a key with TTL |
+| GET | `/api/cache-demo/get/:key` | Get a key (shows hit/miss) |
+| GET | `/api/cache-demo/keys` | List all demo keys |
+| POST | `/api/cache-demo/flush` | Delete all demo keys |
+| GET | `/api/cron` | List cron jobs |
+| POST | `/api/cron` | Create a cron job |
+| POST | `/api/cron/:id/toggle` | Pause / resume a job |
+| DELETE | `/api/cron/:id` | Delete a job |
+| GET | `/api/cron/:id/logs` | Get execution log |
+| POST | `/api/redis-cli` | Execute a Redis command |
+
+---
+
+## Tech Stack
+
+- **Runtime:** Node.js 20, Express
+- **Cache:** Valkey/Redis via [ioredis](https://github.com/redis/ioredis)
+- **Frontend:** React 18, Vite
+- **Platform:** [Embr](https://portal.embr.azure)

client/src/App.jsx

@@ -1,4 +1,6 @@
 import React, { useState, useEffect, useCallback } from 'react';
+import CronJobs from './CronJobs';
+import RedisCli from './RedisCli';
 
 function formatCounter(name) {
   return name.replace(/_/g, ' ');
@@ -148,7 +150,7 @@ function CacheExplorer() {
   };
 
   return (
-    <div className="panel" style={{ gridColumn: '1 / -1' }}>
+    <div className="panel">
       <h2>Cache Explorer <span className="badge">GET / SETEX / TTL</span></h2>
 
       <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 16, marginBottom: 16 }}>
@@ -227,7 +229,11 @@ export default function App() {
         <Counters />
       </div>
 
-      <CacheExplorer />
+      <div className="full-panels">
+        <CacheExplorer />
+        <CronJobs />
+        <RedisCli />
+      </div>
     </div>
   );
 }