update the docker file

src/41-xdp-tcpdump/Dockerfile

@@ -0,0 +1,11 @@
+# Use an official Python runtime as a parent image
+FROM python:3.9-slim
+
+# Set the working directory in the container
+WORKDIR /app
+
+# Expose the port that the HTTP server will run on
+EXPOSE 8000
+
+# Command to run the Python HTTP server
+CMD ["python", "-m", "http.server", "8000"]

src/41-xdp-tcpdump/README.md

@@ -1 +1,35 @@
 # Write a tcpdump in XDP to capture packets
+
+- Write a simple tcpdump in XDP to capture packets
+- See how it works in containers
+
+TODO: Write the document
+
+Here's a simple `Dockerfile` that sets up a Python environment and runs a basic HTTP server using Python's built-in `http.server` module. The network will allow you to `curl` into the Docker container from your host machine.
+
+## Steps to build and run the container:
+
+1. **Build the Docker image:**
+   Navigate to the directory containing the `Dockerfile` and run:
+
+   ```bash
+   docker build -t simple-python-http-server .
+   ```
+
+2. **Run the Docker container:**
+   Run the container and map the internal port `8000` to the host port `8000` so you can access it from your host machine:
+
+   ```bash
+   docker run -d -p 8000:8000 simple-python-http-server
+   ```
+
+   - `-d` runs the container in detached mode (in the background).
+   - `-p 8000:8000` maps port 8000 of the container to port 8000 on your host machine.
+
+3. **Access the server:**
+   Now you can use `curl` to interact with the HTTP server:
+
+   ```bash
+   curl http://localhost:8000
+   ```
+