DASH_DEBUG environment variable not used when running app with gunicorn

Dash Python
1

I’m deploying my app to three different environments (test, acceptance, production). Depending on the environment, the Docker container running the app has different values for the DASH_DEBUG environment variable.
It seems this value is not recognised when launching the app with gunicorn.

Testing locally, this issue is confirmed. First I set the environment variable: export DASH_DEBUG='true'.
Then if I do uv run app.py the app displays the debug interface.
However, if I do uv run gunicorn --bind 0.0.0.0:8050 app:server the app does not display the debug interface.

How can I make it so the environment variable is recognised when launching with gunicorn?

Relevant code snippets:

import dash

...

app = dash.Dash(title='app_title')
# For gunicorn
server = app.server

...

if __name__ == "__main__":
    app.run(host="0.0.0.0")
2

The fix is to call app.enable_dev_tools(). This will read environment variables as desired. E.g.:

import dash

...

app = dash.Dash(title='app_title')
# For gunicorn
app.enable_dev_tools()
server = app.server

...

if __name__ == "__main__":
    app.run(host="0.0.0.0")
1 Like
3

@svdl

Glad you figured it out, gunicorn runs the server directly, that’s why the variables were not read.

Thank you for following up and posting your solution. :slight_smile:

1 Like