contrib

contrib — nono sandbox profile examples

Examples demonstrating nono sandboxing on Kubernetes using nono wrap (direct mode). Each example shows a clear before/after comparison: an unsandboxed baseline pod vs the same workload running inside a nono Landlock sandbox.

What nono wrap enforces

nono wrap applies a Linux Landlock filesystem sandbox to the container process. The default profile (wrap-compatible) restricts:

Access type	Baseline	nono sandbox
Write to /etc/* (host poisoning)	ALLOWED	BLOCKED
Write to /usr/local/bin (backdoor)	ALLOWED	BLOCKED
Read /etc/shadow (credential theft)	ALLOWED	BLOCKED
Read /etc/passwd (user enumeration)	ALLOWED	BLOCKED
Write to Python site-packages (pkg inject)	ALLOWED	BLOCKED
Python / Node / Go runtime	ALLOWED	ALLOWED
Write to /tmp (scratch space)	ALLOWED	ALLOWED

Note on dev profiles: The python-dev, node-dev, and go-dev built-in profiles enable network proxy filtering, which requires nono run (supervisor mode). They are not compatible with nono wrap (direct mode). Use the default profile (or a custom TOML profile without network proxy) with nono wrap.

Profiles covered

Directory	Profile	Sandbox mode	Container image
python-dev	default	nono wrap	python:3.12-slim
node-dev	default	nono wrap	node:20-slim
go-dev	default	nono wrap	golang:1.23-bookworm

Prerequisites

• Kind cluster(s) deployed via deploy/kind/deploy.sh
• kubectl context pointing at the target cluster
• docker and kind in PATH
• nono-nri DaemonSet running: kubectl rollout status daemonset/nono-nri -n kube-system

Image requirement: Demo images are Debian-based with libdbus-1-3, which the nono binary requires at runtime. Alpine / musl images cannot run the nono binary.

Quick start

# containerd cluster (default)
RUNTIME=containerd CLUSTER_NAME=nono-containerd bash contrib/python-dev/demo.sh
RUNTIME=containerd CLUSTER_NAME=nono-containerd bash contrib/node-dev/demo.sh
RUNTIME=containerd CLUSTER_NAME=nono-containerd bash contrib/go-dev/demo.sh

# CRI-O cluster
RUNTIME=crio CLUSTER_NAME=nono-crio bash contrib/python-dev/demo.sh

Recorded demo

An asciinema recording of the python-dev example (containerd cluster) is included:

asciinema play contrib/python-dev/demo.cast

Interactive pods (manual exec)

pod-baseline.yaml and pod-sandbox.yaml run sleep infinity so you can exec in and try commands by hand.

# Build and load image first (see Manual apply below), then:
kubectl apply -f contrib/python-dev/pod-baseline.yaml
kubectl apply -f contrib/python-dev/pod-sandbox.yaml
kubectl wait --for=condition=ready pod/python-dev-baseline pod/python-dev-sandbox --timeout=60s

Baseline — exec directly, no sandbox:

kubectl exec -it python-dev-baseline -- bash
# All of the following succeed:
echo "1.2.3.4 evil" >> /etc/hosts
cat /etc/shadow
echo "x" > /usr/local/bin/exploit
python3 --version

Sandbox — the demo image replaces /bin/bash with a nono wrapper (see Dockerfile). When /nono/nono is bind-mounted by NRI the wrapper automatically invokes nono wrap before handing off to real bash, so plain exec just works:

kubectl exec -it python-dev-sandbox -- bash   # sandboxed automatically
# Inside:
echo "1.2.3.4 evil" >> /etc/hosts   # Permission denied (BLOCKED)
cat /etc/shadow                      # Permission denied (BLOCKED)
python3 --version                    # ALLOWED
echo "ok" > /tmp/workfile            # ALLOWED

Why this works: kubectl exec spawns processes with ppid=0 via the container runtime, bypassing the sandboxed PID 1. Simply wrapping /bin/bash in the image re-applies Landlock for every exec'd shell automatically.

Production guidance: for real workloads prefer a distroless / no-shell image — NRI wraps the app binary and there is no shell to exec into at all. Use Kubernetes ephemeral debug containers (kubectl debug) when you need temporary shell access.

Cleanup:

kubectl delete pod python-dev-baseline python-dev-sandbox

Manual apply (automated Jobs)

# Build and load the image (containerd example)
docker build -t nono-demo-python:latest contrib/python-dev/
docker save nono-demo-python:latest | \
  docker exec -i nono-containerd-control-plane ctr -n k8s.io images import -

# Run both jobs and compare
kubectl apply -f contrib/python-dev/job-baseline.yaml
kubectl apply -f contrib/python-dev/job-sandbox.yaml

kubectl wait --for=condition=complete job/python-dev-baseline --timeout=120s
kubectl wait --for=condition=complete job/python-dev-sandbox  --timeout=120s

kubectl logs job/python-dev-baseline
kubectl logs job/python-dev-sandbox

# Cleanup
kubectl delete job python-dev-baseline python-dev-sandbox