Changing DOMAIN variable in .env file did not make traefik serve the app on that domain

[yohaoquan]

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Example Code

# First part of the .env file at project root
# Domain
# This would be set to the production domain with an env var on deployment
# DOMAIN=localhost
DOMAIN=alang-my.tailscale.machine.ts.net

# Environment: local, staging, production
ENVIRONMENT=local

PROJECT_NAME="My Project Name"
STACK_NAME=my-stack-name

# Backend
# BACKEND_CORS_ORIGINS="http://localhost,http://localhost:5173,https://localhost,https://localhost:5173,http://localhost.tiangolo.com"
BACKEND_CORS_ORIGINS="http://my.tailscale.machine.ts.net,http://my.tailscale.machine.ts.net:5173,https://my.tailscale.machine.ts.net,https://my.tailscale.machine.ts.net:5173,http://my.tailscale.machine.ts.net"

Description

I followed the backend/development.md to change the domain. But even after doing

docker compose up -d

or

docker compose down
# Them manually deleting all related images, then
docker compose up -d

I can see that traefik is still trying to only serve on localhost. Accessing my custom domain returns a 404

Curiously, on the traefik dashboard, only the backend has the updated STACK_NAME applied to my backend, and all the rest still retained the project default stack name:

But no matter, as you can see, it is still trying to serve on localhost despite the fact that my env file changed to use a different domain.

Am I missing some configurations? Can someone help?
Thanks!

Operating System

Windows

Operating System Details

Docker version 26.0.0, build 2ae903e

Python Version

Python 3.12.2

Additional Context

No response

[willhama]

@yohaoquan I might have the answer for you. There seems some misconfiguration within the docker-compose.yml file. Currently it is defined as:

    env_file:
      - .env
    environment:
      - DOMAIN=${DOMAIN}

By priority it takes DOMAIN from your host env variables first and overwrites the one in the .env when you run docker compose up.

Try to execute echo $DOMAIN on your host environment and see whats coming there.

Actually, I am not sure why both are defined in the docker-compose.yml file.

You can remove the following line and it should work fine:

- DOMAIN=${DOMAIN}

@tiangolo why do you declare the environment and the .env file in docker-compose.yml?