convert-to-apple-containerClaude Skill

Convert to Apple Container

This skill switches NanoClaw's container runtime from Docker to Apple Container (macOS-only). It uses the skills engine for deterministic code changes, then walks through verification.

What this changes:

• Container runtime binary: docker → container
• Mount syntax: -v path:path:ro → --mount type=bind,source=...,target=...,readonly
• Startup check: docker info → container system status (with auto-start)
• Orphan detection: docker ps --filter → container ls --format json
• Build script default: docker → container
• Dockerfile entrypoint: .env shadowing via mount --bind inside the container (Apple Container only supports directory mounts, not file mounts like Docker's /dev/null overlay)
• Container runner: main-group containers start as root for mount --bind, then drop privileges via setpriv

What stays the same:

• Mount security/allowlist validation
• All exported interfaces and IPC protocol
• Non-main container behavior (still uses --user flag)
• All other functionality

Prerequisites

Verify Apple Container is installed:

container --version && echo "Apple Container ready" || echo "Install Apple Container first"

If not installed:

• Download from https://github.com/apple/container/releases
• Install the .pkg file
• Verify: container --version

Apple Container requires macOS. It does not work on Linux.

Phase 1: Pre-flight

Check if already applied

grep "CONTAINER_RUNTIME_BIN" src/container-runtime.ts

If it already shows 'container', the runtime is already Apple Container. Skip to Phase 4.

Phase 2: Apply Code Changes

Ensure upstream remote

git remote -v

If upstream is missing, add it:

git remote add upstream https://github.com/qwibitai/nanoclaw.git

Merge the skill branch

git fetch upstream skill/apple-container
git merge upstream/skill/apple-container

This merges in:

• src/container-runtime.ts — Apple Container implementation (replaces Docker)
• src/container-runtime.test.ts — Apple Container-specific tests
• src/container-runner.ts — .env shadow mount fix and privilege dropping
• container/Dockerfile — entrypoint that shadows .env via mount --bind
• container/build.sh — default runtime set to container

If the merge reports conflicts, resolve them by reading the conflicted files and understanding the intent of both sides.

Validate code changes

npm test
npm run build

All tests must pass and build must be clean before proceeding.

Phase 3: Credential proxy network binding

Apple Container uses a bridge network (bridge100) that only exists while containers are running. The credential proxy must start before any container, so it cannot bind to the bridge IP. It must bind to 0.0.0.0, which exposes port 3001 on all network interfaces — anyone on your local network could route API requests through the proxy using your credentials.

Use AskUserQuestion to ask the user:

"The credential proxy needs to bind to all interfaces (0.0.0.0). Is this Mac on a trusted private network?"

Options:

1. Yes, private/home network — description: "No firewall rule needed."
2. No, shared/public network — description: "Add a macOS firewall rule to block external access to port 3001."

For both options, add CREDENTIAL_PROXY_HOST=0.0.0.0 to .env:

grep -q 'CREDENTIAL_PROXY_HOST' .env 2>/dev/null || echo 'CREDENTIAL_PROXY_HOST=0.0.0.0' >> .env

If they chose the public network option, set up and persist the firewall rule:

echo "block in on en0 proto tcp to any port 3001" | sudo pfctl -ef -

grep -q 'nanoclaw proxy' /etc/pf.conf 2>/dev/null || echo '# nanoclaw proxy — block LAN access to credential proxy
block in on en0 proto tcp to any port 3001' | sudo tee -a /etc/pf.conf > /dev/null

Verify the rule is working:

curl -sf http://$(ipconfig getifaddr en0):3001 && echo "EXPOSED — rule not working" || echo "BLOCKED — rule active"

If the verification shows "EXPOSED", warn the user and retry. If "BLOCKED", confirm success and continue.

Phase 4: Verify

Ensure Apple Container runtime is running

container system status || container system start

Build the container image

./container/build.sh

Test basic execution

echo '{}' | container run -i --entrypoint /bin/echo nanoclaw-agent:latest "Container OK"

Test readonly mounts

mkdir -p /tmp/test-ro && echo "test" > /tmp/test-ro/file.txt
container run --rm --entrypoint /bin/bash \
  --mount type=bind,source=/tmp/test-ro,target=/test,readonly \
  nanoclaw-agent:latest \
  -c "cat /test/file.txt && touch /test/new.txt 2>&1 || echo 'Write blocked (expected)'"
rm -rf /tmp/test-ro

Expected: Read succeeds, write fails with "Read-only file system".

Test read-write mounts

mkdir -p /tmp/test-rw
container run --rm --entrypoint /bin/bash \
  -v /tmp/test-rw:/test \
  nanoclaw-agent:latest \
  -c "echo 'test write' > /test/new.txt && cat /test/new.txt"
cat /tmp/test-rw/new.txt && rm -rf /tmp/test-rw

Expected: Both operations succeed.

Full integration test

npm run build
launchctl kickstart -k gui/$(id -u)/com.nanoclaw

Send a message via WhatsApp and verify the agent responds.

Troubleshooting

Apple Container not found:

• Download from https://github.com/apple/container/releases
• Install the .pkg file
• Verify: container --version

Runtime won't start:

container system start
container system status

Image build fails:

# Clean rebuild — Apple Container caches aggressively
container builder stop && container builder rm && container builder start
./container/build.sh

Container can't write to mounted directories: Check directory permissions on the host. The container runs as uid 1000.

Summary of Changed Files

File	Type of Change
src/container-runtime.ts	Full replacement — Docker → Apple Container API
src/container-runtime.test.ts	Full replacement — tests for Apple Container behavior
src/container-runner.ts	.env shadow mount removed, main containers start as root with privilege drop
container/Dockerfile	Entrypoint: mount --bind for .env shadowing, setpriv privilege drop
container/build.sh	Default runtime: docker → container