Message of the Day
for Singularity containers
Note that these were modified for Singularity 3.x due to a loss of functionality to customize the actions shell file. If you are looking for the original recipes for 2.x containers, see release/2.x. The current master should work on both.
What is a message of the day?
If you've ever logged into a linux cluster, or played a computer game like Half Life or World of Warcraft, you might be greeted with some asciiart, or something along the lines of a "tip of the day." This is more official called a "message of the day," (short is motd and there is a bit of history behind it. In short, we print a message to the terminal for the user to see when he or she first logs into a shell.
How can we use motd with containers?
In the context of a container, we might want to give the user a friendly message if they shell inside. The simplest use case is to greet the user. A more useful use case is to provide some help for how to interact with the container, or where to find documentation.
How do we add motd to Singularity containers?
If we are creating a Singularity container,
we can't just echo a message in the runscript, because this gets executed on
a shell or a run. We need to edit the
script that is executed only on a shell.
In this repository, we will provide you with a few fun examples for generating messages of the day in Singularity containers.
- general: will show you how to customize a message for shell, exec, run, or test.
- greeting: a simple message of the day to greet the user
- fortune: give the user a fortune instead, add a cow, and some color!
- help: show the container's %help section to the user when they shell inside
- asciiart: generate a greeting with awesome asciiart!
- graphic: generate a colored graphic to surprise the user with.
Clearly, many of these examples are for fun, and others are better for communicating information. I'm of the firm belief that we should aspire for both - interaction with containers should be both informative and fun.