Refactor Dockerfile to use slim image and multi-stage build

Dockerfile

@@ -1,9 +1,24 @@
-# Usar uma imagem base do Python
-FROM python:3.12
-
+# Build stage: install build dependencies and Python packages
+FROM python:3.12-slim AS builder
 WORKDIR /app
 
-RUN apt-get update && apt-get install -y \
+# Install build dependencies required for compiling C extensions
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    gcc \
+    build-essential \
+    librrd-dev \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy requirements and install Python packages to a separate directory
+COPY requirements.txt /app/
+RUN pip install --prefix=/install --no-cache-dir -r requirements.txt
+
+# Final stage: runtime image
+FROM python:3.12-slim
+WORKDIR /app
+
+# Install necessary runtime packages
+RUN apt-get update && apt-get install -y --no-install-recommends \
     wireguard \
     iptables \
     iproute2 \
@@ -11,29 +26,23 @@ RUN apt-get update && apt-get install -y \
     inetutils-ping \
     inetutils-traceroute \
     nano \
-    vim-nox \
     openssl \
     dnsutils \
     rrdtool \
-    librrd-dev \
+    procps \
     && rm -rf /var/lib/apt/lists/*
 
-# those are the really necessary packages
-#RUN apt-get update && apt-get install -y \
-#    wireguard \
-#    iptables \
-#    openssl \
-#    && rm -rf /var/lib/apt/lists/*
-
-COPY requirements.txt /app/
-RUN pip install --no-cache-dir -r requirements.txt
+# Copy installed Python packages from the builder stage
+COPY --from=builder /install /usr/local
 
+# Copy the application code
 COPY . /app/
 
-RUN chmod +x /app/init.sh
-RUN chmod +x /app/entrypoint.sh
+# Set execution permissions on scripts
+RUN chmod +x /app/init.sh && chmod +x /app/entrypoint.sh
+
 ARG SERVER_ADDRESS
 ARG DEBUG_MODE
-ENTRYPOINT ["/app/entrypoint.sh"]
 
+ENTRYPOINT ["/app/entrypoint.sh"]
 CMD ["/app/init.sh"]