Katacoda demos for SPIRE

Background

This is a temporary repository, linked to my free Katacoda account. Once we have our Katacoda contract this repository should be forked into a general repo in the scytale github where it can be linked to the corporate Katacoda account.

This repo should remain for my own development purposes - and anyone else working on Katacoda demos would simply clone the general repo (once it exists), and link that to their own Katacoda account for development. Cloning into a private, personal repo for development purposes will help insure we don't break existing Katacoda scenarios that customer's might see.

To put it another way: The general Katacoda repository should be considered "release" quality, and all development done in private repositories.

Layout

Things will vary to a fair degree by each individual scenario, and whether they are using k8s, docker-compose, or some other deployment method.

In general, scenarios are organized thusly:

• assets contains all the files that need to be copied to the host to run the scenario. What happens with files in assets is controlled by index.json - files are explicitly copied to a target directory by filename (or simple globbing). Any further moving of files is done in the configure script. Note Katacoda does not allow any subdirectories in assets, so this must be a flat directory with all files. Some of the scenarios, such as the ones based on k8s, use a file naming standard where files are prefixed with the name of the eventual target directory and the configure script is responsible for renaming them where they need to be and the final filename. Also note that it can take quite some time for Katacoda to copy up all the assets. All scenarios contain some logic that waits for files to be uploaded before finishing configuration - be sure to pick a file at the end of the assets list in index.json.
• start_env is a script to bootstrap whatever should be autostarted when the scenario is started, such as waiting for k8s to come up, waiting for assets, running the configure script, and so on. All lines in this script will be echoed to the terminal, so it should be as brief and minimal as possible. Put everything else in configure.
• configure is a script to do additional environment setup, such as rename and move files in assets as discussed above, waiting for k8s to be actually fully up for k8s scenarios (do not rely on launch.sh returning - some bits of k8s necessary for SPIRE won't be started yet), setting the shell prompt, and so on.
• waitfor is a script for docker-compose scenarios that waits for a container to start.

Deploying scenarios

Once a scenario repository is correctly linked to a Katacoda account, deployment involves pushing to the master branch of the repository. It'll take a few minutes for the Katacoda commit hooks to trigger and update.

Other tips

Debugging Katacoda scenarios when they don't work isn't necessarily easy. If the environment boots, then it's just a matter of debugging in the environment, however if (when) the environment doesn't even boot there can be very little feedback about what Katacoda doesn't like in the scenario.

I found it helpful to run scenarios locally before even trying to run them in Katacoda. Generally I start with the directory structure the way I want to see it on the target system and get commands/scripts running locally against either k8s or docker-compose as appropriate. Once I can run through the scenario I move things to assets and decide how they will map into index.json and/or configure to get the files where they need to be.