Asynchronous Python – A Real World Example

Complex Conversions

Introduction

We have a customer that developed a hardware device to make physical measurements. Some years ago we wrote a suite of software tools for the customer: a tablet application for configuring the hardware device, a django web server to receive uploaded XML documents generated by the device, and a user-facing web application (using the same django server), providing reporting and data analytics.

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SSH: Tips Your Grandmother Wished She Knew

Woman holding camera, Photo by Tiago Muraro on Unsplash

Alright, maybe your grandmother doesn’t need tips for using ssh. In fact, she probably doesn’t even know ssh is a secure shell for accessing a remote host.  Go figure.

But I know when I reach the age of grandparenthood and I begin contemplating shuffling off this mortal coil, I will still be using ssh and exploiting its power. (Just you wait: Senior Citizen Geeks, hacking for the pleasure of it…we’re coming sooner than you think.)

As software engineers, particularly those of us who work remotely, we are very dependent on ssh. We use it for remote login. We use it to run remote commands. We use it as a transport for secure software repository access (e.g., git over ssh). The savvy among us install public keys to do this without passwords. But did you know:

  •  You can proxy your ssh connection from one host (say, a gateway to a remote site) to another (i.e., an internal host at the remote site)?
  • Forward arbitrary ports from your computer to the remote host? For example, you are developing a database application and want to test your local development branch against the schema running on the remote server.
  • You can use ssh as a SOCKS server, using your remote connection as your browser’s proxy server?
  • You can use it to subvert firewalls that block that port you need, including the ssh port, 22?
  • You can collect options into a configuration file to run all the above simultaneously without hassle?

In my experience, ssh is one of the most underutilized tools by remote workers. It is my sincere hope that this brief introduction will whet your appetite.

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A Very Useful Conditioner

I am talking about a neat developer tool from Apple for use on Mac OS 10.7 and later. It is called Network Link Conditioner. It is a preference pane that, when installed, will appear in the System Preferences application.

Network Link Conditioner allows you to simulate various kinds of network conditions so that you can test your application for different network speeds. And, that is awesome! When installed in System Preferences, this is how the pane looks:

Software screen capture

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