refactor, add healthz, efficiency and robustness

Dockerfile

@@ -1,7 +1,27 @@
-FROM python:3-slim
+FROM python:3-alpine
+
 WORKDIR /app
+
+# Install build dependencies
+RUN apk add --no-cache --virtual .build-deps gcc musl-dev
+
+# Copy and install requirements
 COPY requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt
+
+# Remove build dependencies
+RUN apk del .build-deps
+
+# Copy the script
 COPY adguard_exporter.py .
+
+# Expose the metrics port
 EXPOSE 8000
+
+# Set environment variables (can be overridden at runtime)
+ENV LOG_FILE_PATH=/adguard/work/data/querylog.json
+ENV METRICS_PORT=8000
+ENV UPDATE_INTERVAL=10
+
+# Run the exporter
 CMD ["python", "./adguard_exporter.py"]