Solutions 12 · Self-hosting and Client Delivery

Exercise 1

Replace Anything Down? → Send Alert with a Code node Detect Changes (Run Once for All Items) after Summary on the scheduled path:

const state = $getWorkflowStaticData('global');
const prev = state.down ?? [];
const now = $input.first().json.down;
const newlyDown = now.filter(u => !prev.includes(u));
const recovered = prev.filter(u => !now.includes(u));
state.down = now;
const lines = [
  ...newlyDown.map(u => `🔴 DOWN: ${u}`),
  ...recovered.map(u => `🟢 RECOVERED: ${u}`),
];
return lines.length ? [{ json: { text: lines.join('\n') } }] : [];

→ Telegram/Slack/Gmail with {{ $json.text }}. Returning [] means no alert. Static data is only saved for production (published) executions, not manual test runs.

Exercise 2

On your machine, in an empty folder with the deploy files and the same .env:

tar -xzf 20261015-023000.tar.gz
docker compose -p restore-test -f docker-compose.prod.yml up -d postgres
gunzip -c 20261015-023000/postgres.sql.gz | docker compose -p restore-test -f docker-compose.prod.yml exec -T postgres psql -U n8n n8n
docker compose -p restore-test -f docker-compose.prod.yml up -d

(Use DOMAIN=localhost locally; Caddy serves a local certificate.) Log in with the original owner account; workflows, credentials and execution history are all in the dump. The workflow and credential JSON files are a second, more portable copy: n8n import:workflow --separate --input=<dir> and n8n import:credentials --separate --input=<dir> load them into any instance with the same encryption key.

Clean up: docker compose -p restore-test -f docker-compose.prod.yml down -v.

Exercise 3

1. Webhook Health API → Authentication: Header Auth → new credential: Name X-Monitor-Token, Value: a long random string (openssl rand -hex 24).
2. Publish.

curl -i https://n8n.yourdomain.com/webhook/ops/health                                   # 403
curl -i -H "X-Monitor-Token: <secret>" https://n8n.yourdomain.com/webhook/ops/health    # 200/503

Configure the same header in your external uptime monitor. Apply this to every webhook that triggers side effects (Modules 03, 07, 10).