Quickstart: Create a Python app in Azure App Service on Linux

Article
02/01/2023

In this quickstart, you deploy a Python web app to App Service on Linux, Azure's highly scalable, self-patching web hosting service. You use the Azure CLI locally from a Windows, Linux, or macOS environment to deploy a sample with either the Flask or Django frameworks. The web app you configure uses a free App Service tier, so you incur no costs in the course of this article.

Tip

If you prefer to deploy apps through an IDE, see Deploy Python apps to App Service from Visual Studio Code.

Set up your initial environment

Have an Azure account with an active subscription. Create an account for free.
Install Python.
Install the Azure CLI 2.0.80 or higher, with which you run commands in any shell to provision and configure Azure resources.

Open a terminal window and check your Python version is 3.6 or higher:

python3 --version

py -3 --version

py -3 --version

Check that your Azure CLI version is 2.0.80 or higher:

az --version

Then sign in to Azure through the CLI:

az login

This command opens a browser to gather your credentials. When the command finishes, it shows JSON output containing information about your subscriptions.

Once signed in, you can run Azure commands with the Azure CLI to work with resources in your subscription.

Having issues? Let us know.

Clone the sample

Clone the sample repository using the following command and navigate into the sample folder. (Install git if you don't have git already.)

git clone https://github.com/Azure-Samples/python-docs-hello-world

Then navigate into that folder:

cd python-docs-hello-world

git clone https://github.com/Azure-Samples/python-docs-hello-django

Then navigate into that folder:

cd python-docs-hello-django

The sample contains framework-specific code that Azure App Service recognizes when starting the app. For more information, see Container startup process.

Having issues? Let us know.

Deploy the sample

Deploy the code in your local folder (python-docs-hello-world) using the az webapp up command:

az webapp up --sku B1 --name <app-name>

If the az command isn't recognized, be sure you have the Azure CLI installed as described in Set up your initial environment.
If the webapp command isn't recognized, because that your Azure CLI version is 2.0.80 or higher. If not, install the latest version.
Replace <app_name> with a name that's unique across all of Azure (valid characters are a-z, 0-9, and -). A good pattern is to use a combination of your company name and an app identifier.
The --sku B1 argument creates the web app on the Basic pricing tier, which incurs a small hourly cost. Omit this argument to use a faster premium tier.
You can optionally include the argument --location <location-name> where <location_name> is an available Azure region. You can retrieve a list of allowable regions for your Azure account by running the az account list-locations command.
If you see the error, "Could not auto-detect the runtime stack of your app," make sure you're running the command in the python-docs-hello-world folder (Flask) or the python-docs-hello-django folder (Django) that contains the requirements.txt file. (See Troubleshooting auto-detect issues with az webapp up (GitHub).)

The command may take a few minutes to complete. While running, it provides messages about creating the resource group, the App Service plan and hosting app, configuring logging, then performing ZIP deployment. It then gives the message, "You can launch the app at http://<app-name>.azurewebsites.net", which is the app's URL on Azure.

Example output of the az webapp up command

Having issues? Let us know.

Note

The az webapp up command does the following actions:

Create a default resource group.
Create a default App Service plan.
Create an app with the specified name.
Zip deploy all files from the current working directory, with build automation enabled.
Cache the parameters locally in the .azure/config file so that you don't need to specify them again when deploying later with az webapp up or other az webapp commands from the project folder. The cached values are used automatically by default.

Browse to the app

Browse to the deployed application in your web browser at the URL http://<app-name>.azurewebsites.net. It takes a few moments to start the app initially.

The Python sample code is running a Linux container in App Service using a built-in image.

Run a sample Python app in Azure

Congratulations! You've deployed your Python app to App Service.

Having issues? Let us know.

Run the sample

Make sure you're in the python-docs-hello-world folder.
Create a virtual environment and install dependencies:
- Bash
- PowerShell
- Cmd
```
# Linux systems only
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

# Git Bash on Windows only
py -3 -m venv .venv
source .venv\\scripts\\activate
pip install -r requirements.txt
```
If you're on a Windows system and see the error "'source' is not recognized as an internal or external command," make sure you're either running in the Git Bash shell, or use the commands shown in the Cmd tab above.
```
py -3 -m venv .venv
.venv\scripts\activate
pip install -r requirements.txt
```
```
py -3 -m venv .venv
.venv\scripts\activate
pip install -r requirements.txt
```
If you encounter "[Errno 2] No such file or directory: 'requirements.txt'.", make sure you're in the python-docs-hello-world folder.
Run the development server.
```
flask run
```
By default, the server assumes that the app's entry module is in app.py, as used in the sample. (If you use a different module name, set the FLASK_APP environment variable to that name.)
Open a web browser and go to the sample app at http://localhost:5000/. The app displays the message Hello, World!.
In your terminal window, press Ctrl+C to exit the development server.

Make sure you're in the python-docs-hello-django folder.
Create a virtual environment and install dependencies:
- Bash
- PowerShell
- Cmd
```
# Linux systems only
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

# Git Bash on Windows only
py -3 -m venv .venv
source .venv\\scripts\\activate
pip install -r requirements.txt
```
If you're on a Windows system and see the error "'source' is not recognized as an internal or external command," make sure you're either running in the Git Bash shell, or use the commands shown in the Cmd tab above.
```
py -3 -m venv .venv
.venv\scripts\activate
pip install -r requirements.txt
```
```
py -3 -m venv .venv
.venv\scripts\activate
pip install -r requirements.txt
```
If you encounter "[Errno 2] No such file or directory: 'requirements.txt'.", make sure you're in the python-docs-hello-django folder.

Run the development server.

python3 manage.py runserver

py -3 manage.py runserver

py -3 manage.py runserver

Open a web browser and go to the sample app at http://localhost:8000/. The app displays the message Hello, World!.
In your terminal window, press Ctrl+C to exit the development server.

Having issues? Let us know.

Redeploy updates

In this section, you make a small code change and then redeploy the code to Azure. The code change includes a print statement to generate logging output that you work with in the next section.

Open app.py in an editor and update the hello function to match the following code.

def hello():
    print("Handling request to home page.")
    return "Hello, Azure!"

Open hello/views.py in an editor and update the hello function to match the following code.

def hello(request):
    print("Handling request to home page.")
    return HttpResponse("Hello, Azure!")

Save your changes, then redeploy the app using the az webapp up command again:

az webapp up

This command uses values that are cached locally in the .azure/config file, including the app name, resource group, and App Service plan.

Once deployment is complete, switch back to the browser window open to http://<app-name>.azurewebsites.net. Refresh the page, which should display the modified message:

Run an updated sample Python app in Azure

Having issues? Let us know.

Tip

Visual Studio Code provides powerful extensions for Python and Azure App Service, which simplify the process of deploying Python web apps to App Service. For more information, see Deploy Python apps to App Service from Visual Studio Code.

Stream logs

You can access the console logs generated from inside the app and the container in which it runs. Logs include any output generated using print statements.

To stream logs, run the az webapp log tail command:

az webapp log tail

You can also include the --logs parameter with then az webapp up command to automatically open the log stream on deployment.

Refresh the app in the browser to generate console logs, which include messages describing HTTP requests to the app. If no output appears immediately, try again in 30 seconds.

You can also inspect the log files from the browser at https://<app-name>.scm.azurewebsites.net/api/logs/docker.

To stop log streaming at any time, press Ctrl+C in the terminal.

Having issues? Let us know.

Manage the Azure app

Go to the Azure portal to manage the app you created. Search for and select App Services.

Navigate to App Services in the Azure portal

Select the name of your Azure app.

Navigate to your Python app in App Services in the Azure portal

Selecting the app opens its Overview page, where you can perform basic management tasks like browse, stop, start, restart, and delete.

Manage your Python app in the Overview page in the Azure portal

The App Service menu provides different pages for configuring your app.

Having issues? Let us know.

Clean up resources

In the preceding steps, you created Azure resources in a resource group. The resource group has a name like "appsvc_rg_Linux_CentralUS" depending on your location. If you keep the web app running, you will incur some ongoing costs (see App Service pricing).

If you don't expect to need these resources in the future, delete the resource group by running the following command: