helm.md

Using Helm with Lostrómos

In order to make migrating to Lostrómos easier we support using Helm to handle the templating. This allows you to provide a Helm chart to Lostrómos.

Tiller

For Lostrómos to be able to run commands with Helm it needs access to a tiller. If you are running inside kubernetes the value for this would look like tiller-deploy:44134 if the tiller is in the same namespace as your Lostrómos deployment. If you are in a different namespace you would use tiller-deploy.<namespace>:44134.

Version

Helm requires the the tiller and the client be running the same version. Currently Lostrómos uses version v2.8.0 of Helm.

Running outside the cluster

If you are running outside of the kubernetes cluster access to the tiller is a little more complicated. It is not a good idea to expose the tiller outside of the cluster since it is not secure by default. Your best option is to use the kubectl port-forward command. This is a simple set of commands you can run that will setup a port forward for you that will work with the default tiller deployment.

export TILLER_NS=kube-system
export TILLER_POD=`kubectl -n $TILLER_NS get pods \
       --selector=app=helm,name=tiller \
       -o jsonpath="{range .items[*]}{@.metadata.name}{end}" | head -n1`
kubectl port-forward -n $TILLER_NS $TILLER_POD 44134:44134

After running this command you would start Lostrómos and set the tiller to point to 127.0.0.1:44134

Using the Custom Resource in your charts

Lostrómos provides access to the resource from within your charts under the variable name resource. The resource has the following fields available on it:

• name - Which is the custom resource name
• namespace - represents the namespace the custom resource is deployed in
• spec - holds all of the data that is stored in your resources spec field.

Given this custom resource

apiVersion: stable.nicolerenee.io/v1
kind: Character
metadata:
  name: nemo
spec:
  Name: Nemo
  From: Finding Nemo
  By: Disney

• {{ .Values.resource.name }} would return "nemo"
• {{ .Values.resource.spec.name }} would return "Nemo"
• {{ .Values.resource.spec.from }} would return "Finding Nemo"
• {{ .Values.resource.spec.by }} would return "Disney"

Using custom repo for charts

For Lostrómos to be able to pull the charts from a remote repository, the remote repository should be pre-configured in the tiller (one option is to add it using helm repo add).

helm repo add foonemo https://username:password@repo.example.com

Add chart entry to the annotations, using the same repo name that was used to add, for the chart to be downloaded from the remote repo.
Chart entry format: <repo name>/<chart name>:[semver]

apiVersion: stable.nicolerenee.io/v1
kind: Character
metadata:
  name: nemo
  annotations:
    chart: foonemo/helloworld:1.2r345
spec:
  Name: Nemo
  From: Finding Nemo
  By: Disney

Note: Set $HELM_HOME env should be set after initializing the repo.