Azure App Service - Autoscaling Streamlit PoC

Deploys a new custom registry in Azure Container Registry, builds a custom Docker image, and runs the image from the custom registry. The image contains a Streamlit demo app.

Running the App

1. Create a new stack:

   $ pulumi stack init dev

2. Login to Azure CLI (you will be prompted to do this during deployment if you forget this step):

   $ az login

3. Create a Python virtualenv, activate it, and install dependencies:

   This installs the dependent packages needed for our Pulumi program.

   $ python3 -m venv venv
   $ source venv/bin/activate
   $ pip3 install -r requirements.txt

4. Specify the Azure location to use:

   $ pulumi config set azure-native:location uksouth

5. Run pulumi up to preview and deploy changes:

   $ pulumi up
   Previewing changes:
   ...
   
   Performing changes:
   ...
   Resources:
       + 5 created
   
   Duration: 56s

6. Check the deployed endpoints:

   $ open $(pulumi stack output endpoint)
   

Building the app locally to test

cd app
docker build -t streamlit-app:latest .
docker run -p 8501:8501 streamlit-app:latest
open "http://localhost:8501"

Limitations

1. PoC uses default Azure domain. In production it will require custom domain and SSL/TLS cert

2. Single dev environment only at present

3. Streamlit's in-memory state handling is potentially not compatible with a scale in/out model in which backend resources are generally considered to be ephemeral. Requires testing.