n8n with Postgres

Run n8n on Lizard (lizard.build) with Managed Postgres and an authenticated JSON webhook. The image pins n8n 2.38.5. The workflow stores a request in Postgres and returns the stored row. Sending the same requestId again returns the first row without adding a duplicate.

This is a single-instance example for JSON workflows. It does not configure queue workers, binary file storage, backups or high availability. Keep the n8n encryption key with the database backup. Attach Persistent Volumes when a workflow needs local files; this example does not test their durability.

Verified deployment

On 9 September 2026, n8n 2.38.5 with Postgres 18.6 passed seven HTTP checks before a service restart and the same seven checks afterwards. The stored row and its creation time stayed the same; the database still held one event. The owner could sign in and see the imported workflow.

• Deployment record
• Before restart and after restart
• Database before and after
• Resource snapshot, a measured rate at one point in time, not a monthly bill
• Running editor, which requires the owner login

The tested runtime code is commit 74458b0f93ee3696dc13d0941137f548e8957718.

Configure a service

Use the Lizard CLI with a project you own:

lizard link --project YOUR_PROJECT
lizard add postgres --name n8n-postgres --region YOUR_REGION
lizard add --repo lizard-build/n8n-postgres-example --name n8n-postgres-example --region YOUR_REGION --no-deploy
lizard domain --service n8n-postgres-example --json

Set these service variables through the dashboard or lizard secrets import. Replace n8n-postgres in each reference if your database has another name.

Variable	Value
N8N_HOST	The public hostname returned by lizard domain, without https://
DB_TYPE	postgresdb
DB_POSTGRESDB_HOST	${{n8n-postgres.PGHOST}}
DB_POSTGRESDB_PORT	${{n8n-postgres.PGPORT}}
DB_POSTGRESDB_DATABASE	${{n8n-postgres.PGDATABASE}}
DB_POSTGRESDB_USER	${{n8n-postgres.PGUSER}}
DB_POSTGRESDB_PASSWORD	${{n8n-postgres.PGPASSWORD}}
N8N_ENCRYPTION_KEY	A random key kept unchanged across deployments
N8N_INSTANCE_OWNER_EMAIL	Your email
N8N_INSTANCE_OWNER_FIRST_NAME	Your first name
N8N_INSTANCE_OWNER_LAST_NAME	Your last name
N8N_INSTANCE_OWNER_PASSWORD_HASH	A bcrypt hash of a strong password
EXAMPLE_WEBHOOK_TOKEN	A separate random webhook key

Owner setup uses n8n's supported environment configuration. It prevents an unclaimed setup page on the public URL. The owner settings apply at each start; change their environment values when you need to change the account.

Set port 5678 and choose the repository Dockerfile explicitly:

lizard service set n8n-postgres-example --set containerPort=5678 --set dockerfilePath=Dockerfile
# Start the first deployment after configuring the service created with --no-deploy.
lizard redeploy --service n8n-postgres-example

The start script derives WEBHOOK_URL and N8N_EDITOR_BASE_URL from N8N_HOST. It also accepts LIZARD_PUBLIC_DOMAIN when the runtime supplies that value. Set N8N_HOST explicitly for a repeatable setup. It uses HTTPS and one trusted proxy hop. If your network adds a proxy, check its forwarding headers and set N8N_PROXY_HOPS to match.

Import the example

Once the service is ready, run these commands from the linked project directory. They create the table and import the two credentials and the workflow. The credential script writes a private temporary file inside the service; n8n stores the imported credentials encrypted with N8N_ENCRYPTION_KEY.

lizard ssh --service n8n-postgres-example -- node /opt/lizard-example/scripts/database.js init
lizard ssh --service n8n-postgres-example -- sh -c 'n8n import:credentials --input="$(node /opt/lizard-example/scripts/prepare-credentials.js)" && n8n import:workflow --input=/opt/lizard-example/workflows/webhook-to-postgres.json && n8n publish:workflow --id=lizardPostgresExample'
lizard restart --service n8n-postgres-example

The CLI publication command requires a restart before the running process registers the webhook. Sign in with the owner account to inspect the imported workflow. Check health and readiness before sending requests.

Check the webhook

Keep the key in an environment variable. Use the production /webhook/ path, not the editor's temporary /webhook-test/ path.

curl --fail-with-body "$N8N_URL/webhook/lizard-postgres-example" \
  -H 'Content-Type: application/json' \
  -H "X-Example-Key: $EXAMPLE_WEBHOOK_TOKEN" \
  --data '{"requestId":"example-001","message":"hello"}'

Use unique request IDs for separate events. This example stores the first body for each ID. A later body with the same ID does not replace it. Send only test data to a demonstration deployment.

Run the repeatable checks from this repository with N8N_URL and EXAMPLE_WEBHOOK_TOKEN already set in your local environment:

python3 scripts/check-webhook.py --url "$N8N_URL" --output before-restart.json
lizard restart --service n8n-postgres-example
# Wait for /healthz/readiness to return 200, then reuse the saved request ID.
REQUEST_ID=$(python3 -c 'import json; print(json.load(open("before-restart.json"))["requestId"])')
python3 scripts/check-webhook.py --url "$N8N_URL" --output after-restart.json --request-id "$REQUEST_ID"
lizard ssh --service n8n-postgres-example -- node /opt/lizard-example/scripts/database.js

Compare both storedRow values, including created_at, and the database row count. The test checks valid authentication, a retry with a changed body, missing and wrong keys, and an unknown webhook path.

Sources

• n8n 2.38.5 release
• Docker Compose installation
• Postgres configuration
• Owner settings
• n8n CLI
• Lizard deployment documentation

The files here configure n8n; they do not change its license. See n8n's license.