DevOps Python Monitor

Real-time log watching and containerized metrics app

    
# log_watcher.py
import time
import os

LOG_FILE = "/var/log/syslog"  # Change to your log path
KEYWORDS = ["ERROR", "CRITICAL"]

def tail(file):
    file.seek(0, os.SEEK_END)
    while True:
        line = file.readline()
        if not line:
            time.sleep(0.5)
            continue
        if any(kw in line for kw in KEYWORDS):
            print(f"[ALERT] {line.strip()}")

if __name__ == "__main__":
    try:
        with open(LOG_FILE, "r") as f:
            print(f"Monitoring {LOG_FILE} for {KEYWORDS}...")
            tail(f)
    except FileNotFoundError:
        print("Log file not found!")
    
  

    
# app.py (Flask with Prometheus metrics)
from flask import Flask
from prometheus_client import Counter, generate_latest

app = Flask(__name__)
REQUESTS = Counter('app_requests_total', 'Total number of requests')

@app.route('/')
def home():
    REQUESTS.inc()
    return "Hello from DevOps Flask App!"

@app.route('/metrics')
def metrics():
    return generate_latest(), 200, {'Content-Type': 'text/plain'}

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000)
    
  

    
# Dockerfile
FROM python:3.10-slim
WORKDIR /app
COPY app.py requirements.txt ./
RUN pip install -r requirements.txt
EXPOSE 5000
CMD ["python", "app.py"]
    
  

    
# requirements.txt
flask
prometheus_client

    
# docker-compose.yaml
version: '3'
services:
  web:
    build: .
    ports:
      - "5000:5000"
  prometheus:
    image: prom/prometheus
    volumes:
      - ./prometheus.yml:/etc/prometheus/prometheus.yml
    ports:
      - "9090:9090"
    
  

    
# prometheus.yml
scrape_configs:
  - job_name: 'flask_app'
    static_configs:
      - targets: ['web:5000']
    
  