Hello World!
Like many other people who are having to migrate from Heroku to other providers (
), and I am having a hard time learning the “correct tricks” to get my application running on Render’s servers.
My application has basically this skeleton:
import dash
import dash_auth
import dash_bootstrap_components as dbc
from dash import dcc, html, Output, Input, State, dash_table
app = dash.Dash(__name__,
meta_tags=[
{'name': 'viewport', 'content': 'width=device-width, initial-scale=1.0, maximum-scale=1.2, minimum-scale=0.5,'}],
external_stylesheets=[dbc.themes.QUARTZ])
server = app.server
app.title = 'Title'
app.layout = dbc.Container(fluid=True, children=[])
@app.callback(
[Output('some_stuff', 'children'),],
[Input('stuff', 'value')])
def display_something(value):
return value
if __name__ == '__main__':
app.run_server(debug=False)
The source code is in a private repository on Github (assets folder, requirements.txt, gitignore, the whole thing). So:
- I connect the repository to Render as a
Web Service; - use the
Build Command = pip install --upgrade pip setuptools wheel && pip install -r requirements.txt(I was getting errors because of the old pip version, so I am updating it). - and use the
Start Command(and here is where I think the error is…)gunicorn app:app(on heroku I useweb: gunicorn app:server).
After the deployment I get the following error:
AppImportError: Application object must be callable.
As far as I understand, Render cannot call the application. Why is this?
Other information that might help someone else to enlighten my path.
- The name of the file containing the application is
app.py(does this create a conflict?). - The version of python that I specify to Render is
3.8.0.
I think the ero is in the Start Command. Can anyone tell me what would be the right command for this application?
Thanks for your attention!
