demo: more demos

Author: sfermigier

demos/demo29/app/app.py

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+# Copyright (c) 2025, Abilian SAS
+# SPDX-License-Identifier: Apache-2.0
+"""Demo 29: Native Python app with MySQL addon - Page Counter.
+
+A simple Flask application deployed natively (without Docker) that connects
+to a MySQL database provisioned via Hop3 addons. Implements a basic page view counter.
+"""
+from __future__ import annotations
+
+import os
+from datetime import datetime
+
+from flask import Flask, jsonify
+
+app = Flask(__name__)
+
+# Get DATABASE_URL from environment (set by Hop3 when addon is attached)
+# MySQL addon provides: DATABASE_URL, MYSQL_HOST, MYSQL_PORT, MYSQL_USER, MYSQL_PASSWORD, MYSQL_DATABASE
+DATABASE_URL = os.environ.get("DATABASE_URL")
+
+
+def get_db_connection():
+    """Get a database connection if DATABASE_URL is configured."""
+    if not DATABASE_URL:
+        return None
+
+    import mysql.connector
+
+    # Use individual env vars for more reliability
+    return mysql.connector.connect(
+        host=os.environ.get("MYSQL_HOST", "localhost"),
+        port=int(os.environ.get("MYSQL_PORT", "3306")),
+        user=os.environ.get("MYSQL_USER"),
+        password=os.environ.get("MYSQL_PASSWORD"),
+        database=os.environ.get("MYSQL_DATABASE"),
+    )
+
+
+def init_db():
+    """Initialize the database table if it doesn't exist."""
+    conn = get_db_connection()
+    if not conn:
+        return False
+
+    try:
+        cursor = conn.cursor()
+        cursor.execute("""
+            CREATE TABLE IF NOT EXISTS page_views (
+                id INT AUTO_INCREMENT PRIMARY KEY,
+                page VARCHAR(100) NOT NULL,
+                view_count INT DEFAULT 0,
+                last_viewed TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+                UNIQUE KEY unique_page (page)
+            ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
+        """)
+        conn.commit()
+        cursor.close()
+        conn.close()
+        return True
+    except Exception:
+        return False
+
+
+def increment_counter(page: str = "home") -> int:
+    """Increment the page view counter and return the new count."""
+    conn = get_db_connection()
+    if not conn:
+        return -1
+
+    try:
+        cursor = conn.cursor()
+        # Insert or update the counter
+        cursor.execute("""
+            INSERT INTO page_views (page, view_count)
+            VALUES (%s, 1)
+            ON DUPLICATE KEY UPDATE view_count = view_count + 1
+        """, (page,))
+        conn.commit()
+
+        # Get the current count
+        cursor.execute("SELECT view_count FROM page_views WHERE page = %s", (page,))
+        result = cursor.fetchone()
+        count = result[0] if result else 0
+
+        cursor.close()
+        conn.close()
+        return count
+    except Exception:
+        return -1
+
+
+@app.route("/")
+def home():
+    """Home page with page counter."""
+    db_configured = DATABASE_URL is not None
+
+    if db_configured:
+        count = increment_counter("home")
+        if count == -1:
+            return jsonify({
+                "app": "demo29",
+                "type": "native + mysql",
+                "message": "Welcome to demo29 - Native MySQL Page Counter!",
+                "database_configured": True,
+                "error": "Failed to increment counter",
+            })
+        return jsonify({
+            "app": "demo29",
+            "type": "native + mysql",
+            "message": "Welcome to demo29 - Native MySQL Page Counter!",
+            "database_configured": True,
+            "page_views": count,
+            "timestamp": datetime.now().isoformat(),
+        })
+
+    return jsonify({
+        "app": "demo29",
+        "type": "native + mysql",
+        "message": "Welcome to demo29 - Native MySQL Page Counter!",
+        "database_configured": False,
+        "hint": "Attach a MySQL addon to enable the counter",
+    })
+
+
+@app.route("/db-status")
+def db_status():
+    """Check database connection status."""
+    if not DATABASE_URL:
+        return jsonify({"status": "not_configured", "message": "DATABASE_URL not set"})
+
+    try:
+        conn = get_db_connection()
+        cursor = conn.cursor()
+        cursor.execute("SELECT VERSION()")
+        version = cursor.fetchone()[0]
+        cursor.close()
+        conn.close()
+        return jsonify({
+            "status": "connected",
+            "version": version,
+            "database": os.environ.get("MYSQL_DATABASE"),
+        })
+    except Exception as e:
+        return jsonify({"status": "error", "error": str(e)}), 500
+
+
+@app.route("/db-init")
+def db_init():
+    """Initialize the database table."""
+    if not DATABASE_URL:
+        return jsonify({"status": "not_configured"}), 400
+
+    success = init_db()
+    if success:
+        return jsonify({"status": "success", "message": "Database initialized"})
+    return jsonify({"status": "error", "message": "Failed to initialize"}), 500
+
+
+@app.route("/counter")
+def counter():
+    """Get the current page view count without incrementing."""
+    if not DATABASE_URL:
+        return jsonify({"status": "not_configured"}), 400
+
+    try:
+        conn = get_db_connection()
+        cursor = conn.cursor()
+        cursor.execute("SELECT page, view_count, last_viewed FROM page_views ORDER BY view_count DESC")
+        rows = cursor.fetchall()
+        cursor.close()
+        conn.close()
+
+        counters = [
+            {"page": row[0], "views": row[1], "last_viewed": row[2].isoformat() if row[2] else None}
+            for row in rows
+        ]
+        return jsonify({"status": "success", "counters": counters})
+    except Exception as e:
+        return jsonify({"status": "error", "error": str(e)}), 500
+
+
+@app.route("/db-test")
+def db_test():
+    """Test database operations (create table, insert, query)."""
+    if not DATABASE_URL:
+        return jsonify({"status": "not_configured"}), 400
+
+    try:
+        # Initialize DB first
+        init_db()
+
+        # Increment counter
+        count = increment_counter("test")
+
+        return jsonify({
+            "status": "success",
+            "test_page_views": count,
+            "message": "MySQL operations working!",
+        })
+    except Exception as e:
+        return jsonify({"status": "error", "error": str(e)}), 500
+
+
+@app.route("/health")
+def health():
+    """Health check endpoint."""
+    return jsonify({"status": "healthy"})
+
+
+if __name__ == "__main__":
+    port = int(os.environ.get("PORT", 5000))
+    app.run(host="0.0.0.0", port=port)

demos/demo29/app/hop3.toml

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+# hop3.toml - Native Python app with MySQL addon
+
+[metadata]
+id = "demo29-mysql-counter"
+version = "0.1.0"
+title = "Native MySQL Page Counter Demo"
+description = "Demonstrates native Python deployment with MySQL addon - simple page view counter"
+
+[build]
+# Use native Python builder (no Docker)
+builder = "python-3.12"
+pip-install = ["-r", "requirements.txt"]
+
+[run]
+start = "gunicorn --workers 2 --bind 0.0.0.0:$PORT app:app"

demos/demo29/app/requirements.txt

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+flask>=3.0.0
+gunicorn>=21.0.0
+mysql-connector-python>=8.0.0