05_templating_practice.md

Template challenge

Here you’ll be able to practice in order to get familiar with some of the possibilities offered by a templating language.

(pro tip: Don't forget the testing)

These examples may seem useless but the purpose of this is just playing with templates.

1 - "Configuration depends on region"

Create a secret that contains a key 'secret' and a value "myEuropeanSecret". Set an environment variable from this secret only if the value global.region is 'eu-west1' So the first step is to add the values into the values.yaml file.

global:
  region: eu-west-1

2 - "Create only if"

Create a job that prints the pod's IP on stdout based on a boolean value printIP.enabled. Use the "busybox" image and the command wget -qO - http://ipinfo.io/ip. The job should be created only if the value is True, before every other resource has been created (pre-install and pre-upgrade hooks)

3 - "Looping"

Given the following values, create a loop whether in the deployment or in the helpers.tpl file in order to add the environment variables.

envVars:
  key1: value1
  key2: value2
  key3: value3

4 - "Playing with strings and sprigs"

Add to the "common labels", a new label "codename" with a value composed with the release name, the chart name and the date in the form 20061225. The release name must be at most 3 characters long. The whole string has to be in snakecase.

(you should get something like codename: rel_web_20210215)

5 - We want to create a list of etcd hosts in the form of "etcd-0,etcd-1,etcd-2" based on a integer that defines the number of etcd hosts

etcd:
  count: 5

This list has to be defined in an environment variable ETCD_HOSTS

You can find here possible solutions