Why am I unable to connect my self-hosted n8n to Digital Ocean's managed PostgreSQL database?

Below is a checklist to help resolve the SSL and connection issues:

1. Use the Correct Environment Variable Names

n8n expects the PostgreSQL variables to follow a specific naming scheme. For example, instead of using:

YAMLCopied
DB_TYPE: "postgres"
DB_POSTGRESDB: "your-database"

you’ll need:

• DB_TYPE=postgresdb
• DB_POSTGRESDB_DATABASE=your-database
• DB_POSTGRESDB_USER=your-user
• DB_POSTGRESDB_PASSWORD=your-password
• DB_POSTGRESDB_HOST=your-host
• DB_POSTGRESDB_PORT=5432

2. Provide the SSL CA Certificate

Since Digital Ocean’s managed PostgreSQL enforces SSL for connections, you must supply the CA certificate. Add the following environment variable:

YAMLCopied
DB_POSTGRESDB_SSL_CA: "/certs/ca.crt"

You can also optionally set whether to reject unauthorized certificates (for testing you might disable it, but it’s not recommended in production):

YAMLCopied
DB_POSTGRESDB_SSL_REJECT_UNAUTHORIZED: "true"

3. Make the Certificate Available to the Container

Ensure that the certificate file (for example, the one provided by Digital Ocean) is mounted into the container. For example:

YAMLCopied
volumes:
  - ~/.n8n:/home/node/.n8n
  - ./certs:/certs

Place your ca.crt file inside the ./certs directory relative to your docker-compose file.

4. Update the YAML File

An updated example might look like this:

YAMLCopied
version: '3'
services:
  n8n:
    image: n8nio/n8n
    environment:
      DB_TYPE: "postgresdb"
      DB_POSTGRESDB_DATABASE: "your-database"
      DB_POSTGRESDB_USER: "your-user"
      DB_POSTGRESDB_PASSWORD: "your-password"
      DB_POSTGRESDB_HOST: "your-host"
      DB_POSTGRESDB_PORT: "5432"
      DB_POSTGRESDB_SSL_CA: "/certs/ca.crt"
      DB_POSTGRESDB_SSL_REJECT_UNAUTHORIZED: "true"
      N8N_HOST: "your-domain.com"
      N8N_PORT: "5678"
      N8N_PROTOCOL: "http"
    volumes:
      - ~/.n8n:/home/node/.n8n
      - ./certs:/certs
    restart: always
    ports:
      - "5678:5678"

5. Check the Host Configuration

If you’re running n8n behind a reverse proxy (or simply expecting external access), note that using localhost as N8N_HOST restricts your access to the local machine only. Replace N8N_HOST with your actual domain or IP (for example, your-domain.com) if you intend for it to be publicly accessible.

Summary

• Rename environment variables to match n8n’s expected names for Postgres.
• Add the SSL CA variable (DB_POSTGRESDB_SSL_CA) and make sure the file is mounted in the container.
• Verify your N8N_HOST is set correctly for your access scenario.

Once these changes are applied, rerun docker-compose up. This should resolve the SSL error and allow n8n to connect to your Digital Ocean managed PostgreSQL database successfully.