I am unable to save a Postgres credential for my Supabase database. The connection test always fails.
The strange and important fact is that I can connect to the exact same Supabase database from the host server’s command line using psql. This proves that there are no firewall or network blocking issues between my server and Supabase. The problem seems to be specific to n8n running inside Docker.
What is the error message (if any)?
The error in the n8n UI is:
Could not connect with these settings
There are no specific errors in the n8n container logs when I attempt to save the credential. The logs are clean.
Please share your workflow
This issue happens at the credential creation stage, so there is no workflow to share. No node can be executed because the credential cannot be saved.
Share the output returned by the last node
Not applicable.
Information on your n8n setup
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n8n version: 1.104.1
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Database (default: SQLite): SQLite (default)
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n8n EXECUTIONS_PROCESS setting (default: own, main): default
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Running n8n via (Docker, npm, n8n cloud, desktop app): Docker
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Operating system: Ubuntu (on Hetzner Cloud)
Additional context that might help:
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I have methodically tested all three connection URIs provided by Supabase (Transaction Pooler, Session Pooler, and the Direct Connection). I carefully used the correct host, port (6543 or 5432), user, and password for each one. None of them work from the n8n credential manager.
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The server has plenty of free RAM (>3GB) and low CPU usage.
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The n8n UI is running perfectly behind an Nginx reverse proxy.
Here is my docker-compose.yml:
version: ‘3.8’
services:
n8n:
image: n8nio/n8n:1.104.1
container_name: n8n_main
restart: always
network_mode: host
env_file:
- .env
environment:
- WEBHOOK_URL=https://box.asadnur.com/
volumes:
- n8n_data:/home/node/.n8n
volumes:
n8n_data:
Thank you for your help