Move Scapy to dev requirements

Author: dotchance

CONTRIBUTING.md

@@ -12,7 +12,7 @@ Thanks for improving rudder. This repository is focused on Linux eBPF TC packet
 Run the lightweight checks before opening a pull request:
 
 ```bash
-python -m pip install -r requirements.txt
+python -m pip install -r requirements-dev.txt
 python -m unittest discover -s tests -p 'test_*.py'
 python -m compileall rudder.py engine tests
 python - <<'PY'

README.md

@@ -95,7 +95,14 @@ sudo apt-get install -y \
 pip3 install -r requirements.txt
 ```
 
-This installs `click` (CLI framework), `PyYAML` (rule parsing), `pyroute2` (ARP neighbor table lookup), and `scapy` (test packet generation).
+This installs `click` (CLI framework), `PyYAML` (rule parsing), and `pyroute2`
+(ARP neighbor table lookup).
+
+The Scapy packet generator is optional and lives in the dev/test requirements:
+
+```bash
+pip3 install -r requirements-dev.txt
+```
 
 ## Building the eBPF Programs
 
@@ -361,6 +368,11 @@ ls /sys/fs/bpf/rudder/ 2>/dev/null       # Directory should not exist
 ## Testing with Generated Traffic
 
 The included packet generator uses Scapy to send crafted packets for validating rules.
+Install the dev/test requirements before using it:
+
+```bash
+pip3 install -r requirements-dev.txt
+```
 
 ### Test Steer Rules
 
@@ -429,7 +441,7 @@ A full test cycle on a machine with `eth0`, `eth1`, `eth2`, and `eth3`:
 # 1. Install dependencies
 sudo apt-get install -y libbpf-dev linux-headers-$(uname -r) \
     linux-tools-generic clang llvm iproute2 tcpdump
-pip3 install -r requirements.txt
+pip3 install -r requirements-dev.txt
 
 # 2. Load steering and replication rules
 sudo python3 rudder.py load rules/example_steer.yaml rules/example_replicate.yaml
@@ -529,7 +541,8 @@ rudder/
 ├── CODE_OF_CONDUCT.md         # Community expectations
 ├── CONTRIBUTING.md            # Development and validation notes
 ├── SECURITY.md                # Vulnerability reporting and security scope
-└── requirements.txt           # Python dependencies
+├── requirements.txt           # Runtime Python dependencies
+└── requirements-dev.txt       # Optional dev/test dependencies
 ```
 
 ## Limits

deploy/Dockerfile

@@ -17,11 +17,12 @@ RUN apt-get update && apt-get install -y \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /rudder
-COPY requirements.txt .
+COPY requirements.txt requirements-dev.txt ./
 
 # The base image is a general Ubuntu environment, so this install intentionally
-# uses the system Python. Rudder is not packaged as a Python wheel yet.
-RUN pip3 install --break-system-packages -r requirements.txt
+# uses the system Python. The lab image installs dev/test requirements so
+# tests/gen_packets.py is available for packet-generation experiments.
+RUN pip3 install --break-system-packages -r requirements-dev.txt
 
 COPY . .
 

deploy/README.md

@@ -19,7 +19,8 @@ userspace dependency on a host.
 ## Files
 
 - `Dockerfile` builds an Ubuntu-based lab image with Python, clang/LLVM,
-  `bpftool`, `tc`, `tcpdump`, and Rudder's Python dependencies.
+  `bpftool`, `tc`, `tcpdump`, Rudder's runtime Python dependencies, and the
+  optional dev/test dependency used by `tests/gen_packets.py`.
 - `pod.yaml` shows a privileged K3s/Multus pod with multiple attached
   interfaces and the host mounts needed for eBPF map pinning and kernel headers.
 

requirements-dev.txt

@@ -0,0 +1,9 @@
+# Copyright 2025-2026 .chance (dotchance)
+# Licensed under the Apache License, Version 2.0. See LICENSE file.
+
+-r requirements.txt
+
+# Scapy is only needed for tests/gen_packets.py. Keep it out of the default
+# runtime requirements because Rudder does not use Scapy in the daemon, CLI
+# policy path, TC attachment path, or eBPF map serialization path.
+scapy==2.5.0

requirements.txt

@@ -4,4 +4,3 @@
 click==8.1.7
 pyroute2==0.7.9
 PyYAML==6.0.1
-scapy==2.5.0