I feel your pain matteodefelice. I’m having exactly the same issue:
I am using the latest version of VSCode and have written the simplest of dash apps:
from dash import Dash, dcc, html
app = Dash(__name__)
app.layout = html.Div([
dcc.Markdown(''' ### Ayup python world ''')
if __name__ == '__main__'
This runs on my localhost without issue.
I have a folder on my desktop named “practice” and I used “python -m venv venv” to set up a virtual environment. I then activated the venv using “venv\Scripts\activate”, downloaded dash using “pip install dash” and generated a requirements.txt file “pip freeze > requirements.txt”.
To learn how to use Microsoft Azure I set-up a free trail acount and also installed Docker on my laptop.
I then installed the Azure and Docker extensions in VScode and then generated an image of my app using Docker:
CTRL-SHIFT P Docker Images: Build Image…
Couldn’t find a Dockerfile in your workspace. Would you like to add Docker files to the workspace? Python General Enter a Python module instead - app.py include optional Docker Compose files? - No
Here’s the Dockerfile:
# For more information, please refer to https://aka.ms/vscode-docker-python
# Keeps Python from generating .pyc files in the container
# Turns off buffering for easier container logging
# Install pip requirements
COPY requirements.txt .
RUN python -m pip install -r requirements.txt
COPY . /app
# Creates a non-root user with an explicit UID and adds permission to access the /app folder
# For more info, please refer to https://aka.ms/vscode-docker-python-configure-containers
RUN adduser -u 5678 --disabled-password --gecos "" appuser && chown -R appuser /app
# During debugging, this entry point will be overridden. For more information, please refer to https://aka.ms/vscode-docker-python-debug
CMD ["python", "-m", "app.py"]
New folder structure ‘’’ practice: >venv >.vscode .dockerignore app.py Dockerfile requirements.text ‘’’ After running Docker Images the app ran on my localhost with no issues.
I then went to my Azure subscription and setup a container registry, a resource group and an App service:
Create a resource Container Registry - Create Subscription - Azure subscription 1 Resource group - Create new - mick-practice-resource-group Registry name - mickPracticeRegistry Location - Canada Central Pricing plan - Basic Review and Create - Validation passed Create - Deployment succeeded
App Services Create - Web App Subscription - Azure subscription 1 Resource group - Create new - mick-practice-resource-group Name - mickPracticeApp Publish - Docker Container Operating System - Linux Location - Canada Central Linux plan - (New) ASP-mickpracticeresorucegroup-809e Pricing plan - Free F1 (Shared infrastructure) Zone redundancy - Disabled Review and Create Create - Your deployment is complete
I then went back to VSCode to the Docker extension: under Images Right Click on Practice:latest Push - mickpracticeregistry.azurecr.io/practice:latest Push successful
App opened on http://127.0.0.1:8050/ without issue
In Docker went to Registries, clicked connect icon and connected. clicked refresh and practice folder appeared dropdown revealed latest right clicked on latest and selected Deploy Image to Azure App Service… Name: mickPracticeWebApp Resource group: mick-practice-resource-group Service plan: ASP-mickpracticeresorucegroup-809e
Successfully created web app “mickPracticeWebApp” https://mickpracticewebapp.azurewebsites.net
Clicked Open Site
Do you want Code to open external website? Open
New window opens with Loading and circling ellipse until “ Application Error If you are the application administrator, you can access the diagnostic resources.”
I have spent a couple of days trying to understand what’s happening to no avail. I think this has something to do with the app.run_server() line. I have also tried with app.run_server(host=‘0.0.0.0’, port='8050) and app.run_server(host=‘0.0.0.0’, port='80).
It’s driving me crazy. I’ve scoured the web for an answer but nothing works. Have you had any feedback that works?