refactor: enhance Dockerfile build flow

- Re-arranged steps order to install requirements before copying backend for better caching.
- Introduced a healthcheck command to monitor the application status.
- Set environment variables and documented the exposed port for better container management.

Author: atyrode

Dockerfile

@@ -1,14 +1,45 @@
+# Frontend build stage
 FROM node:20-slim as frontend-builder
 WORKDIR /app/frontend
+
+# Copy package files first to leverage layer caching
 COPY src/frontend/package.json src/frontend/yarn.lock ./
 RUN yarn install --frozen-lockfile
+
+# Copy all frontend files
 COPY src/frontend/ ./
+
+# Build the frontend
 RUN yarn build
 
+# Backend stage
 FROM python:3.11-slim
 WORKDIR /app
-COPY src/backend /app
+
+# Copy requirements first to leverage layer caching
+COPY src/backend/requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt
+
+# Install curl for healthcheck
+RUN apt-get update && apt-get install -y --no-install-recommends curl && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/*
+
+# Copy backend files
+COPY src/backend .
+
+# Copy built frontend from the frontend-builder stage
 COPY --from=frontend-builder /app/frontend/dist /app/frontend/dist
 
-CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"] 
+# Add healthcheck
+HEALTHCHECK --interval=30s --timeout=30s --start-period=5s --retries=3 \
+  CMD curl -f http://localhost:8000/ || exit 1
+
+# Set environment variables
+ENV PYTHONUNBUFFERED=1
+
+# Document the port number the container will expose
+EXPOSE 8000
+
+# Run the application
+CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]