Tag archive for: Flask

How to solve “No API definition provided” error for Flask-RESTPlus app on Cloud Foundry

When you create an API endpoint that generates a QRCode with Flask-RESTPlus, you may want to deploy it onto Cloud Foundry.

However, when I first tried to do so, I was greeted with a No API definition provided when I accessed the Swagger Api portal page.

qrcodeapp showing No API definition provided

So why is there a “No API definition provided” error for Flask-RESTPlus app on Cloud Foundry?

In case you are facing such a problem, this post discuss how I had managed to solve the “No API definition provided” error for my Flask-RESTPlus app on Cloud Foundry.

How to create an API endpoint that generates a QR Code image, with Python 3 Flask-RESTPlus and python-qrcode

When you have an API endpoint that generates a QR Code image, another device with a QR Code scanner will be able to get the encoded value to perform some action. For example, WhatsApp web generates a QR Code image that encodes a code for WhatsApp app to sign in the user.

So how can you create an API endpoint that generates a QR Code image? With this in mind, let’s look at how we can do so with Python 3 Flask-RESTPlus and python-qrcode.

Getting the environment variables supplied to your Cloud Foundry application with Python 3 Flask

When I was trying to build a Python 3 Flask application on Cloud Foundry, I wanted to quickly check the environment variables that Cloud Foundry will supply to my application.

As a result of that, I created a Python 3 Flask application that will probe the environment variables that it receives from Cloud Foundry.

This post lists the files that constitute that Python 3 Flask application.

How to use Flask-APScheduler in your Python 3 Flask application to run multiple tasks in parallel, from a single HTTP request

When you build an API endpoint that serves HTTP requests to work on long-running tasks, consider using a scheduler. Instead of holding up a HTTP client until a task is completed, you can return an identifier for the client to query the task status later. In the meantime, your HTTP server can offload the task to a scheduler which will complete it and update the status.

When you are building your HTTP server with Python 3 Flask, Flask-APScheduler gives you the facilities to schedule tasks to be executed in the background.

In this post, we look at how we can get Flask-APScheduler to run multiple tasks in parallel, from a single HTTP request.