OVH Guides

Installing Helm on OVH Managed Kubernetes

Find out how to install Helm on OVH Managed Kubernetes

Last updated 25th February, 2019.

Helm is a package manager for Kubernetes. It works with packages of pre-configured Kubernetes resources, called Helm charts.

With Helm you can:

Before you begin

This tutorial assumes that you already have a working OVH Managed Kubernetes cluster, and some basic knowledge of how to operate it. If you want to know more on those topics, please look at the OVH Managed Kubernetes Service Quickstart.

We are assuming that you have the KUBECONFIG environment variable pointing to your KubeCtl configuration file, as described in the Quickstarter. If that's not the case, you can use the --kubeconfig [LOCATION_OF_CONFIG_FILE] option in both kubectl and helm calls.

Installing Helm

Helm has two parts: the client part, helm, and the server part, tiller. To use Helm on your OVH Managed Kubernetes cluster, you need to deploy tiller in the cluster and to install helm on your workstation.

The simplest way to install Helm is grabbing the binary release for your platform on the official release page. You then just need to unpack the client helm binary and add it to your PATH.

To use alternative installation procedures, like package managers (Homebrew, Snap etc.), please refer to the official installation doc.

Once you have helm ready, you can use it to install tiller on your cluster. helm will install tilller in the current kubectl cluster. We assume that your cluster is already configured. If not, please refer to the relevant OVH documentation, and verify you're pointing to the right target by executing:

kubectl cluster-info

Before installing Tiller (the Helm server-side component) on your cluster, you need to create a service account for it, and assigning this account admin roles in your cluster:

kubectl create serviceaccount --namespace kube-system tiller
kubectl create clusterrolebinding tiller-cluster-rule --clusterrole=cluster-admin --serviceaccount=kube-system:tiller
kubectl patch deploy --namespace kube-system tiller-deploy -p '{"spec":{"template":{"spec":{"serviceAccount":"tiller"}}}}'

You can then install tiller on your Kubernetes cluster in one step:

helm init

Tiller (the Helm server-side component) has been installed into your Kubernetes Cluster.

Please note: by default, Tiller is deployed with an insecure 'allow unauthenticated users' policy. To prevent this, run helm init with the --tiller-tls-verify flag. For more information on securing your installation, see the official helm doc.

Happy Helming!

$ helm init
Creating /Users/user/.helm
Creating /Users/user/.helm/repository
Creating /Users/user/.helm/repository/cache
Creating /Users/user/.helm/repository/local
Creating /Users/user/.helm/plugins
Creating /Users/user/.helm/starters
Creating /Users/user/.helm/cache/archive
Creating /Users/user/.helm/repository/repositories.yaml
Adding stable repo with URL: https://kubernetes-charts.storage.googleapis.com
Adding local repo with URL: http://127.0.0.1:8879/charts
$HELM_HOME has been configured at /Users/user/.helm.

Securing your Helm installation

The default Helm installation doesn't apply any security configuration. If you're using Helm in a production context, or in a shared environment, please read this guide to Securing your Helm Installation page.

Updating the Helm repository

Before installing any package with helm, you need you update its repository, to ensure it is equipped with the most recent versions.

helm repo update 

Helm will download the repository:

$ helm repo update
Hang tight while we grab the latest from your chart repositories...
...Skip local chart repository
...Successfully got an update from the "stable" chart repository
Update Complete. ⎈ Happy Helming!⎈

Installing an example chart

Let's validate your Helm installation by installing an example chart, the official Redis one, with no persistence:

helm install --set master.persistence.enabled=false stable/redis

Troubleshooting

If you get an Error: no available release name found when installing the stable/redis chart, please try the following steps:

kubectl create serviceaccount --namespace kube-system tiller
kubectl create clusterrolebinding tiller-cluster-rule --clusterrole=cluster-admin --serviceaccount=kube-system:tiller
kubectl patch deploy --namespace kube-system tiller-deploy -p '{"spec":{"template":{"spec":{"serviceAccount":"tiller"}}}}'
helm init --skip-refresh --upgrade --service-account-tiller

This will install the required elements and initialise the services. And at the end, it will give you the connection parameters for your new Redis database:

$ helm install --set master.persistence.enabled=false stable/redis
NAME:   aged-garfish
LAST DEPLOYED: Mon Oct 15 15:03:35 2018
NAMESPACE: default
STATUS: DEPLOYED

RESOURCES:
==> v1/Secret
NAME                AGE
aged-garfish-redis  1s

==> v1/ConfigMap
aged-garfish-redis-health  1s

==> v1/Service
aged-garfish-redis-master  1s
aged-garfish-redis-slave   1s

==> v1beta1/Deployment
aged-garfish-redis-slave  1s

==> v1beta2/StatefulSet
aged-garfish-redis-master  0s

==> v1/Pod(related)

NAME                                       READY  STATUS             RESTARTS  AGE
aged-garfish-redis-slave-6596cb6d6c-56vs6  0/1    ContainerCreating  0         0s
aged-garfish-redis-master-0                0/1    ContainerCreating  0         0s


** Note: Please be patient while the chart is being deployed **

Redis can be accessed via port 6379 on the following DNS names from within your cluster:

aged-garfish-redis-master.default.svc.cluster.local for read/write operations
aged-garfish-redis-slave.default.svc.cluster.local for read-only operations


To get your password, run:

    export REDIS_PASSWORD=$(kubectl get secret --namespace default aged-garfish-redis -o jsonpath="{.data.redis-password}" | base64 --decode)

To connect to your Redis server:

1. Run a Redis pod that you can use as a client:

   kubectl run --namespace default aged-garfish-redis-client --rm --tty -i \
    --env REDIS_PASSWORD=$REDIS_PASSWORD \
   --image docker.io/bitnami/redis:4.0.11-debian-9 -- bash

2. Connect using the Redis CLI:
3. 
   redis-cli -h aged-garfish-redis-master -a $REDIS_PASSWORD
   redis-cli -h aged-garfish-redis-slave -a $REDIS_PASSWORD

To connect to your database from outside the cluster, execute the following commands:

    kubectl port-forward --namespace default svc/aged-garfish-redis 6379:6379 &
    redis-cli -h 127.0.0.1 -p 6379 -a $REDIS_PASSWORD

Verifying your Redis

After installing the chart, follow the instructions on your console to test your Redis deployment.

Cleaning up

To clean up your cluster, simply delete your Redis installation. You can use helm list to get the Redis release, and then helm delete [REDIS_RELEASE].

$$ helm delete aged-garfish
release "aged-garfish" deleted

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