How can I fix the n8n Cloud SQL PostgreSQL connection error on Cloud Run using a Unix socket?

Based on your configuration, there are a couple of items to check:

1. Use the Correct Database Type

n8n requires the environment variable for Postgres to be set as follows:

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export DB_TYPE=postgresdb

Your configuration uses DB_TYPE=postgres. This mismatch means n8n isn’t parsing your PostgreSQL settings correctly, which can lead to errors like the one you’re seeing.

2. Check for Typos in Environment Variables

There’s a minor typo in your environment variables. For example, you have:

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N8N_ENFORCE_SETTINGS_FILE_PERMISSION=ture

It should be:

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N8N_ENFORCE_SETTINGS_FILE_PERMISSION=true

3. Verify the Unix Socket Path

While your Unix socket path appears correctly formed, ensure that:

• The Cloud SQL Unix socket is accessible from your Cloud Run instance.
• The path you set in DB_POSTGRESDB_HOST (e.g. /cloudsql/project:europe-west1:n8n/.s.PGSQL.5432) is correct as per your Cloud SQL instance configuration.

4. Command Execution

The error “command start not found” suggests that after the configuration issues, n8n isn’t able to properly recognize the command you’re issuing. Once the environment variables are corrected, make sure you are starting n8n with the proper command:

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n8n start

Next Steps

1. Change DB_TYPE=postgres to DB_TYPE=postgresdb.
2. Correct the typo in N8N_ENFORCE_SETTINGS_FILE_PERMISSION to true.
3. Double-check your Unix socket path.
4. Restart the service using n8n start and monitor the logs for any further issues.

These adjustments should help n8n correctly load your Postgres configuration on Cloud Run.

It looks like your environment variables are mostly in order, but one key thing stands out: the value of DB_TYPE. In n8n, to use Postgres, the documentation requires setting

  DB_TYPE=postgresdb

instead of

  DB_TYPE=postgres

When DB_TYPE isn’t set to one of the supported values (either sqlite or postgresdb), the configuration may not be parsed correctly. This can lead to errors such as the one you’re seeing:

  Cannot read properties of undefined (reading 'database')

Additionally, double-check your other environment variable values. For example:

• N8N_ENFORCE_SETTINGS_FILE_PERMISSION=ture
  (This looks like it might be a typo—if you intended to enforce file permission, it should be set to true, not ture.)

Since you’re using a Unix socket (via Cloud SQL’s Cloud Run integration), make sure that the DB_POSTGRESDB_HOST variable correctly points to the Cloud SQL socket. The sample value in the docs is a hostname, but when using Unix sockets with Cloud Run you typically set it to the socket path. Ensure that the service account and Cloud SQL instance permissions are set up correctly. (Since you mentioned that other simple apps work with these settings, this likely isn’t the primary issue.)

In summary, try these steps:

1. Change DB_TYPE=postgres to DB_TYPE=postgresdb.
2. Correct any typos in your environment variables (e.g., change N8N_ENFORCE_SETTINGS_FILE_PERMISSION=ture to true).

Once these changes are made, re-run your container. If the configuration is now recognized correctly, the “command start not found” and the related TypeError should be resolved.

Let me know if you need further assistance!