Add prometheus-flask-exporter for Flask metrics + fix postgres-exporter port

Author: akhil27051999

app/__init__.py

@@ -1,6 +1,7 @@
 from flask import Flask, jsonify
 from flask_sqlalchemy import SQLAlchemy
 from flask_migrate import Migrate
+from prometheus_flask_exporter import PrometheusMetrics
 from .logger import setup_logger
 
 db = SQLAlchemy()
@@ -22,6 +23,10 @@ def create_app(config_class=None):
     app.logger.setLevel(student_logger.level)
     app.logger.propagate = False  # Prevent double logging
 
+    # Prometheus metrics — exposes /metrics endpoint
+    metrics = PrometheusMetrics(app)
+    metrics.info('flask_app_info', 'Flask App Info', version='1.0.0')
+
     app.logger.info("Student Management API started successfully.")
 
     # init db & migrations

app/requirements.txt

@@ -22,3 +22,4 @@ python-dotenv==1.1.1
 SQLAlchemy==2.0.43
 typing_extensions==4.14.1
 Werkzeug==3.1.3
+prometheus-flask-exporter==0.23.1

helm/prometheus/values.yaml

@@ -51,7 +51,7 @@ extraScrapeConfigs: |
 
   - job_name: 'postgres-exporter'
     static_configs:
-      - targets: ['postgres-exporter-prometheus-postgres-exporter.observability.svc.cluster.local:80']
+      - targets: ['postgres-exporter-prometheus-postgres-exporter.observability.svc.cluster.local:9187']
 
   - job_name: 'blackbox-http'
     metrics_path: /probe