Docker networking issue with Supabase connection after migrating from Docker Desktop to native Docker

[kotys2022]

Description:
I'm experiencing connectivity issues with Archon after migrating from Docker Desktop to native Docker on Linux (due to conflicts with NVIDIA Container Toolkit).
Environment:

OS: Linux
Docker: Native Docker (not Docker Desktop)
Supabase: Running in Docker container supabase-kong on port 8000
Network: supabase_default bridge network

Problem:
Previously with Docker Desktop, this configuration worked:
envSUPABASE_URL=http://host.docker.internal:8000

After switching to native Docker, the following issues occur:

1. **Using `host.docker.internal:8000`**: Connection timeout

httpx.ConnectTimeout: timed out
Error loading credentials: timed out

2. **Using container name `supabase-kong:8000`**: HTTPS validation error

ConfigurationError: Supabase URL must use HTTPS for non-local environments (hostname: supabase-kong)

Using IP 172.17.0.1:8000: Connection timeout from within container

Current docker-compose.yml configuration:

Services connected to both app-network and supabase_default networks
extra_hosts includes host.docker.internal:host-gateway

Expected behavior:
Archon services should connect to local Supabase container using HTTP without HTTPS validation errors.
Possible solutions:

Add supabase-kong to allowed local hostnames in validate_supabase_url() function
Add environment variable to disable HTTPS validation for local development (e.g., DISABLE_SSL_VALIDATION=true)
Update documentation for native Docker deployment

Question:
What is the recommended way to configure SUPABASE_URL when both Archon and Supabase are running in Docker containers on the same machine using native Docker (not Docker Desktop)?

[kotys2022]

Here's the solution for GitHub:

---

Solution: Allow Docker container names in Supabase URL validation

The issue was that the validate_supabase_url() function in python/src/server/config/config.py only allowed specific hostnames (localhost, 127.0.0.1, host.docker.internal) and private IP addresses for HTTP connections. Docker container names like supabase-kong were being rejected.

Fix:

In python/src/server/config/config.py, line ~109, modify the hostname validation to allow Docker container names:

Option 1: Add specific container name

python

# Check for exact localhost and Docker internal hosts (security: prevent subdomain bypass)
local_hosts = ["localhost", "127.0.0.1", "host.docker.internal", "supabase-kong"]
if hostname in local_hosts or hostname.endswith(".localhost"):
    return True

Option 2: Allow all Docker container names (recommended)

python

# Check for exact localhost and Docker internal hosts
local_hosts = ["localhost", "127.0.0.1", "host.docker.internal"]
# Allow Docker container names (hostnames without dots)
if hostname in local_hosts or hostname.endswith(".localhost") or "." not in hostname:
    return True

Configuration:

In .env:

env

SUPABASE_URL=http://supabase-kong:8000

In docker-compose.yml, ensure services are connected to the Supabase network:

yaml

services:
  archon-server:
    networks:
      - app-network
      - supabase_default  # External Supabase network

networks:
  app-network:
    driver: bridge
  supabase_default:
    external: true

Why this works:

• Docker container names (without dots) are local to the Docker network and should be treated as local development environments
• This allows HTTP connections between containers on the same Docker network
• HTTPS is still enforced for external domains (containing dots)

This solution works for native Docker on Linux where host.docker.internal is not available by default.