add blogpost and cdn chall

services/cdn/chall/Dockerfile

@@ -0,0 +1,21 @@
+FROM python:3.12-slim
+
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1 \
+    PIP_NO_CACHE_DIR=1
+
+WORKDIR /app
+
+RUN apt-get update \
+ && apt-get install -y --no-install-recommends libimage-exiftool-perl \
+ && rm -rf /var/lib/apt/lists/*
+
+COPY requirements.txt .
+RUN pip install -r requirements.txt
+
+COPY . /app
+RUN chmod +x /app/entrypoint.sh \
+ && mkdir -p /app/uploads && chmod 755 /app/uploads
+
+EXPOSE 8000
+ENTRYPOINT ["/bin/bash", "entrypoint.sh"]