Create app.py

app.py

@@ -0,0 +1,173 @@
+import os
+import psutil
+import psycopg2
+from flask import Flask, jsonify, request
+
+app = Flask(__name__)
+
+DB_CONFIG = {
+    "host": os.getenv("DB_HOST", "localhost"),
+    "port": int(os.getenv("DB_PORT", 5432)),
+    "dbname": os.getenv("DB_NAME", "mydb"),
+    "user": os.getenv("DB_USER", "myuser"),
+    "password": os.getenv("DB_PASSWORD", "mypassword"),
+}
+
+EXPECTED_LIMITS = {
+    "cpu_cores": 1,
+    "ram_gb": 8,
+    "storage_gb": 20,
+    "max_db_connections": 50,
+}
+
+
+def get_db_connection():
+    return psycopg2.connect(**DB_CONFIG)
+
+
+def get_system_stats():
+    cpu_percent = psutil.cpu_percent(interval=0.1)
+    cpu_count = psutil.cpu_count(logical=False) or psutil.cpu_count()
+
+    vm = psutil.virtual_memory()
+    ram_total_gb = vm.total / (1024**3)
+    ram_used_gb = (vm.total - vm.available) / (1024**3)
+    ram_percent = vm.percent
+
+    disk = psutil.disk_usage("/")
+    disk_total_gb = disk.total / (1024**3)
+    disk_used_gb = disk.used / (1024**3)
+    disk_percent = disk.percent
+
+    return {
+        "cpu": {
+            "usage_percent": cpu_percent,
+            "cores_detected": cpu_count,
+            "expected_cores": EXPECTED_LIMITS["cpu_cores"],
+        },
+        "ram": {
+            "total_gb": ram_total_gb,
+            "used_gb": ram_used_gb,
+            "usage_percent": ram_percent,
+            "expected_gb": EXPECTED_LIMITS["ram_gb"],
+        },
+        "disk": {
+            "total_gb": disk_total_gb,
+            "used_gb": disk_used_gb,
+            "usage_percent": disk_percent,
+            "expected_gb": EXPECTED_LIMITS["storage_gb"],
+        },
+    }
+
+
+def get_db_stats():
+    try:
+        conn = get_db_connection()
+        cur = conn.cursor()
+        cur.execute("SELECT COUNT(*) FROM pg_stat_activity;")
+        current_connections = cur.fetchone()[0]
+        cur.execute("SHOW max_connections;")
+        max_connections = int(cur.fetchone()[0])
+        cur.close()
+        conn.close()
+
+        return {
+            "current_connections": current_connections,
+            "max_connections": max_connections,
+            "expected_max_connections": EXPECTED_LIMITS["max_db_connections"],
+        }
+    except Exception as e:
+        return {
+            "error": str(e),
+            "current_connections": None,
+            "max_connections": None,
+        }
+
+
+@app.route("/")
+def index():
+    system_stats = get_system_stats()
+    db_stats = get_db_stats()
+
+    doc = {
+        "description": "PostgreSQL + Flask service exposed on /api",
+        "endpoints": {
+            "/": {
+                "method": "GET",
+                "description": "System + DB stats and endpoint documentation",
+            },
+            "/api": {
+                "method": "GET",
+                "description": "Simple API root, returns health and DB connectivity",
+            },
+            "/api/query": {
+                "method": "POST",
+                "description": "Execute an arbitrary SQL query. Body: JSON {\"query\": \"SELECT ...\"}",
+            },
+        },
+        "expected_resources": EXPECTED_LIMITS,
+        "system_stats": system_stats,
+        "db_stats": db_stats,
+    }
+
+    return jsonify(doc)
+
+
+@app.route("/api")
+def api_root():
+    try:
+        conn = get_db_connection()
+        cur = conn.cursor()
+        cur.execute("SELECT 1;")
+        result = cur.fetchone()[0]
+        cur.close()
+        conn.close()
+        db_status = "ok" if result == 1 else "unexpected_result"
+    except Exception as e:
+        db_status = f"error: {e}"
+
+    return jsonify({
+        "status": "ok",
+        "db_status": db_status,
+    })
+
+
+@app.route("/api/query", methods=["POST"])
+def api_query():
+    data = request.get_json(silent=True) or {}
+    query = data.get("query")
+
+    if not query:
+        return jsonify({"status": "error", "error": "Missing 'query' in JSON body"}), 400
+
+    try:
+        conn = get_db_connection()
+        cur = conn.cursor()
+        cur.execute(query)
+
+        rows = None
+        if cur.description is not None:
+            cols = [d[0] for d in cur.description]
+            rows = [dict(zip(cols, r)) for r in cur.fetchall()]
+
+        try:
+            conn.commit()
+        except Exception:
+            conn.rollback()
+
+        cur.close()
+        conn.close()
+
+        return jsonify({
+            "status": "ok",
+            "rows": rows,
+        })
+    except Exception as e:
+        return jsonify({
+            "status": "error",
+            "error": str(e),
+        }), 500
+
+
+if __name__ == "__main__":
+    app.run(host="0.0.0.0", port=7860)