In a previous blog post we have seen how to use Docker for developing Python web applications. In this blog post we shall see how to deploy thusly dockerised web application on the CERN OpenStack cloud, for example to demonstrate the application to colleagues.
I've been using excellent msync tool to synchronise IMAP mailboxes between cloud and laptop. (mbsync seems both faster and less resource-hungry than offlineimap.) Once, probably due to a wrong move operation, the synchronisation started to report "Maildir error: duplicate UID" messages. How to quickly repair this situation?
A Docker container is usually dedicated to running one daemon process, such as Apache to serve a web application. If the application needs a cache, or a database, then the container running the application is linked to another containing running the cache, and yet another container running the database. However, what if we need (or want) to run several daemon applications inside the same single container?
Docker became popular software solution permitting to deploy applications inside isolated Linux software containers. From a Python related point of view, one could consider Docker containers as "virtual environments on steroids", because they encapsulate and isolate not only application's Python pre-requisites (say given version of PyPDF2 package), but also any non-Python utilities of the operating system that the application relies on (say given version of LibreOffice). The following primer shows how to use Docker for developing Python applications.
In search for greater keyboard ergonomy and improved typing productivity, the CapsLock key seems to be taking place for not much use. Many programmers redefine it to become a modifier key. One popular habit: Vi users prefer to set it to Escape, while Emacs users to Control. What if one likes both?