How to set up n8n workflow automation on Heroku platform

Other Questions N8n
1

I’m struggling to get the n8n workflow automation tool running on Heroku using Docker containers. The deployment keeps failing and I can’t figure out what’s causing the issue.

Here’s my setup process:

First, I create a PostgreSQL database addon:

heroku addons:create heroku-postgresql:mini --version=12 -a workflow-app

My Docker configuration file:

FROM n8nio/n8n:latest

Configuration in heroku.yml:

setup:
  config:
    APP_SUBDOMAIN: "workflow-app"
    HOST_DOMAIN: "herokuapp.com"
    ENVIRONMENT: "production"
    TIMEZONE: "America/New_York"
    N8N_BASIC_AUTH_ACTIVE: "true"
    N8N_HOST: "${APP_SUBDOMAIN}.${HOST_DOMAIN}"
    N8N_PORT: "${PORT}"
    N8N_PROTOCOL: "https"
    N8N_ENCRYPTION_KEY: "myencryptionkey123"
    WEBHOOK_URL: "https://${APP_SUBDOMAIN}.${HOST_DOMAIN}/"
    DATABASE_TYPE: "postgresdb"
    DB_POSTGRESDB_HOST: "postgres-host"
    DB_POSTGRESDB_DATABASE: "workflow_db"
    DB_POSTGRESDB_PORT: 5432
    DB_POSTGRESDB_USER: "postgres_user"
    DB_POSTGRESDB_PASSWORD: "postgres_pass"

build:
    docker:
        web: Dockerfile

The error logs show:

2020-04-15T12:30:15.234567+00:00 app[web.1]: [ERROR tini (1)] Process manager warning detected
2020-04-15T12:30:15.234890+00:00 app[web.1]: su-exec: permission denied
2020-04-15T12:35:20.567123+00:00 heroku[router]: at=error code=H10 desc="Application crashed" method=GET path="/" host=workflow-app.herokuapp.com

What am I missing in my configuration? Any suggestions would be helpful.

2

The permission error you’re encountering is typically related to Heroku’s container runtime environment. I faced a similar issue when deploying n8n and found that the default n8n Docker image doesn’t play well with Heroku’s security model. Your main problem is in the Dockerfile - using FROM n8nio/n8n:latest directly won’t work because Heroku runs containers as non-root users, but the n8n image expects certain permissions. You need to modify your Dockerfile to handle this properly. Also, your database configuration looks hardcoded. Heroku provides the database connection string through the DATABASE_URL environment variable automatically when you add the PostgreSQL addon. You should parse this URL instead of manually setting each database parameter. The H10 error suggests your application isn’t binding to the correct port. Make sure your container is listening on the port specified by Heroku’s $PORT environment variable, not a hardcoded port number.

3

I ran into this exact problem a few months ago when migrating from self-hosted to Heroku. The root cause is usually the heroku.yml configuration structure you’re using. The setup section isn’t valid for Heroku container deployments - you need to move all those environment variables to your app’s config vars instead. Run heroku config:set for each variable or set them through the dashboard. Your Dockerfile also needs a proper CMD instruction since Heroku containers require an explicit entry point. Try adding CMD ["n8n", "start"] to your Dockerfile. Another thing that caught me off guard was the database connection - Heroku’s postgres addon automatically sets DATABASE_URL, so you might be overcomplicating it by setting individual DB variables. The permission error often resolves once you fix the configuration structure and let Heroku handle the database connection properly.

4

looks like your encryption key is way too simple - heroku needs stronger keys or it might reject the deployment. also check if your postgres addon actually created the database variables correctly with heroku config command, sometimes the connection fails silently.