Update Dockerfile

Dockerfile

@@ -10,8 +10,8 @@ RUN pip install --upgrade pip
 # Install dependencies
 RUN pip install -r requirements.txt
 
-# Install ngrok
-RUN apt-get update && apt-get install -y unzip \
+# Install ngrok and DNS utilities
+RUN apt-get update && apt-get install -y unzip dnsutils \
     && curl -s https://ngrok-agent.s3.amazonaws.com/ngrok.asc | tee /etc/apt/trusted.gpg.d/ngrok.asc \
     && echo "deb https://ngrok-agent.s3.amazonaws.com buster main" | tee /etc/apt/sources.list.d/ngrok.list \
     && apt-get update && apt-get install ngrok
@@ -22,5 +22,8 @@ COPY app/. /app/.
 # Expose port for application
 EXPOSE 8001
 
-# Start ngrok and the flask application
+# Add a health check for DNS resolution
+HEALTHCHECK --interval=30s --timeout=5s --retries=3 CMD nslookup connect.ngrok-agent.com || exit 1
+
+# Start ngrok and the Flask application
 CMD ngrok http 8001 --log=stdout & python /app/main.py