Quickstart guide for a Python application

In this guide, you'll learn the process of deploying a Python application on Wasmer Edge, in particular a Python http server. We will cover installation of the CLI, setting up a new Python HTTP server, and deploying it.

Deploying a Python application

Install Wasmer

Click here for instructions on how to install Wasmer if you haven't done it already!

Initialize the local directory

With the CLI installed, let's create a new Python application! We begin creating a new empty directory - after that, we will need to run a single command.

$ mkdir my-python-http-server 
$ cd my-python-http-server
$ wasmer deploy --template=python-http-server             
It seems you are trying to create a new app!
✔ Who should own this app? · <you> 
✔ What should be the name of the app? · <your-app-name> 
✔ Unpacked template
✔ Do you want to deploy the app now? · yes
Loading local package (manifest path: <current-working-directory>)
✔ Correctly built package locally
✔ Package correctly uploaded
✔ Succesfully pushed release to namespace <you> on the registry 
Deploying app <your-app-name> (<you>) to Wasmer Edge...
 
App <your-app-name> (<you>) was successfully deployed 🚀
https://<your-app-name>-<you>.wasmer.app
 
→ Unique URL: https://<app_id>.id.wasmer.app
→ Dashboard:  https://wasmer.io/apps/<you>/<your-app-name>
 
Waiting for new deployment to become available...
(You can safely stop waiting now with CTRL-C)
.
𖥔 Deployment complete

The wasmer deploy --template=python-http-server command will prompt you for the following:

App owner: This is the owner of the app. It can be your username or an organization; if you're logged in, the command will prompt you to choose from your namespaces: by default, it will be your username.
App name: This is the name of your app. By default, it will be the name of the current directory.

The above command will do the following:

Download the template from the registry
Deploy it to Wasmer Edge with the user-provided informations

Let's check it:

$ curl https://<your-app-name>-<you>.wasmer.app
{"message": "Python app is running with Wasmer!"}%

Update the app

Your directory should now look like this:

main.py

wasmer.toml

README.md

LICENSE

app.yaml

To illustrate the lifecycle of an app, let's edit the main.py file in the src folder:

src/main.py

import os
import json
from http.server import SimpleHTTPRequestHandler, HTTPServer
 
 
class CustomHandler(SimpleHTTPRequestHandler):
    def do_GET(self):
        self.send_response(200)
        self.send_header('Content-type', 'application/json')
        self.end_headers()
 
        data = {
            "message": "wasmer/python-http-server is running on Python!", # <-- Notice the comma!
            "hello": "world" # <- New line
        }
        self.wfile.write(json.dumps(data).encode('utf-8'))
 
 
if __name__ == "__main__":
    host = os.environ.get('HOST', '127.0.0.1')
 
    # Get the PORT environment variable if it's present; otherwise, default to 8000
    port = int(os.environ.get('PORT', 80))
 
    server = HTTPServer((host, port), CustomHandler)
    print(f"Starting server on http://{host}:{port}")
    server.serve_forever()

Let's re-deploy our Python HTTP server:

$ wasmer deploy
Loading local package (manifest path: <current-working-directory>)
✔ Correctly built package locally
✔ Package correctly uploaded
✔ Succesfully pushed release to namespace <you> on the registry 
Deploying app <your-app-name> (<you>) to Wasmer Edge...
 
App <your-app-name> (<you>) was successfully deployed 🚀
https://<your-app-name>-<you>.wasmer.app
 
→ Unique URL: https://<app_id>.id.wasmer.app
→ Dashboard:  https://wasmer.io/apps/<you>/<your-app-name>
 
Waiting for new deployment to become available...
(You can safely stop waiting now with CTRL-C)
.
𖥔 Deployment complete

Let's try to cURL the server:

$ curl https://<your-app-name>-<you>.wasmer.app
{"message": "Python app is running with Wasmer!", "hello": "world"}%

Testing your Python application locally

To run your Python application locally simply run

$ wasmer run . --env PORT=9090
Starting server on http://127.0.0.1:9090

This will start a local server on http://localhost:9090.

ℹ️

You can see all the available options with wasmer run --help or click here to see the full documentation.

Let's try to cURL the server:

$ curl http://127.0.0.1:9090
{"message": "Python app is running with Wasmer!"}%

Conclusion

Congratulations! You have successfully deployed a Python HTTP server on Wasmer Edge 🚀.

Tip: To make changes to your Python HTTP server, simply modify the main.py file in the src directory and run wasmer deploy again to deploy the changes.

Resources

wasmer-examples/python-wasmer-starter

JS service worker Rust (Axum) HTTP server