Challenge 09 - Helm - Coach’s Guide

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Notes & Guidance

You should deliver a demo in addition to the lecture to show what a working Helm chart looks like.
- Consider using the app-languages-helm-chart helm chart provided in the Coach Solutions folder for Challenge 9 as one that can be demoed during the lecture.
You should provide guidance in the challenge as to which values should be parameterized in the Helm templates.
- At a minimum make sure the version label is parameterized (ie: v1, v2, etc) so that students can install different versions of the app using helm install easily.
NOTE: Helm 3 does not automatically create namespaces.
- The YAML files in the Student Resources folder provides a YAML file that creates a whatthehack namespace. - This should only be used when installing the app manually during the first part of the challenge.
NOTE: When creating their helm charts make sure that students are handling namespaces properly:
- Students should NOT include the namespace YAML in the helm chart
- The application’s YAML files should NOT include a namespace, we will leave namespace creation up to helm (see below).

Helm Commands

First let’s install our new chart and make sure it is in the releases as well as check that everything is deployed in Kubernetes

NOTE: Take special note of the helm install command and how we are telling it to create a new namespace. Because we did NOT put a namespace in the yaml file templates in our Chart, those resources will go into the namespace we pass into the -n parameter, in our case mynamespace. We’re also using the --create-namespace option so that mynamespace will be created if it doesn’t already exist.
```
# install Helm chart
helm install --create-namespace -n mynamespace --set appData.imageVersion=v2 langfacts-release2 langfacts

# check that the helm chart shows installed and working
helm list -A

# check that all the resources we expect in our new namespace are present
kubectl get all -n mynamespace
```

Next we’ll lay out all the commands needed to create the chart using the app-languages-helm-chart folder in the Coach Solutions for Challenge 9 and get it pushed up to your Azure Container Registry

First of all we need to allow admin access and authenticate ourselves with the ACR and add it as a helm repository on our local system

# enable admin user on ACR
az acr update -n myacr -g myrg --admin-enabled true

# get credentials for Admin user on ACR (save these values)
az acr credential show -n myacr -g myrg 

# login Helm to ACR using admin credentials (use values from above for -u and -p)
export HELM_EXPERIMENTAL_OCI=1
helm registry login myacr.azurecr.io -u myuser -p mypass

# Add ACR as Helm Repo and confirm it is in the list
az acr helm repo add --name myacr
helm repo list

Now we can package up the app-languages-helm-chart chart and push it to our ACR helm repo
- Packaging creates a tarball using the name of our chart provided in Chart.yaml
```
# package Helm chart
helm package app-languages-helm-chart

# push Helm Chart to ACR
az acr helm push -n myacr langfacts-0.1.0.tgz
```

Now let’s update our local repo’s index and search to see if the langfacts chart is available

# update Helm repo
helm repo update

# search for the langfacts chart to make sure it got uploaded
helm search repo lang

Finally let’s install our new chart and make sure it is in the releases as well as check that everything is deployed in Kubernetes
- NOTE: Take special note of the helm install command and how we are telling it to create a new namespace. Because we did NOT put a namespace in the yaml file templates in our Chart, those resources will go into the namespace we pass into the -n parameter, in our case mynamespace. We’re also using the --create-namespace option so that mynamespace will be created if it doesn’t already exist.
```
# install Helm chart
helm install --create-namespace -n mynamespace --set appData.imageVersion=v2 langfacts-release2 myacr/langfacts

# check that the helm chart shows installed and working
helm list -A

# check that all the resources we expect in our new namespace are present
kubectl get all -n mynamespace
```

Extra Credit

You can also change the challenge to turn the existing YAML files for the FabMedical app they’ve been working on into a helm chart. This lets the attendees build on what they have already completed. The end result should be the same.