The Automation Broker works in conjunction with the Kubernetes Service Catalog to make services and applications easily deployable. An end user selects a service to be provisioned, selects a “plan” that describes the level of service (small, large, paid, free, persistent, ephemeral, etc), and then provides any required parameters. In this scenario, Helm charts can be utilized in two possible ways.
- The Automation Broker’s “helm registry adapter” can inspect a chart repository and make each discovered chart available as a service class. The chart’s
values.yamlfile is made available as a single parameter for a single default plan.
- The tool
helm2bundlecreates a Service Bundle image that includes a specific chart. The image can be modified like any service bundle, including changes to metadata such as those in
This post introduces the Helm registry adapter, making Helm charts available as service classes.
Deploy with the Helm Registry Adapter
Our Broker's application definition is written in Ansible as an Ansible Playbook Bundle (APB). This allows us to run the APB as a pod in the cluster, like below. Before deploying the Broker, just ensure that your cluster is running and has the service-catalog installed.
$ cat <<EOF | kubectl create -f -
# Since the Broker APB will create CRDs and other privileged
# k8s objects, we need elevated permissions
- kind: ServiceAccount
- name: apb
- "-e create_broker_namespace=true"
- "-e broker_sandbox_role=admin"
- "-e broker_dockerhub_tag=canary"
- "-e broker_helm_enabled=true"
- "-e broker_helm_url=https://kubernetes-charts.storage.googleapis.com"
- "-e wait_for_broker=true"
To follow the logs:
$ kubectl logs -n automation-broker-apb automation-broker-apb -f
Once the Broker is installed and registered with the service-catalog, you should see Helm charts listed as services in the OpenShift Web Console:
Using Helm Charts
There are two ways to make use of these Helm charts:
- Without Tiller - If Tiller cannot be found in the target namespace/project, then the objects are added to the cluster using the
- With Tiller - If Tiller can be found in the target namespace/project, then
helm installis used to install the chart.
- From the list of available services in the OpenShift Web Console, select "Tiller".
- We will create a new project
helm-demowhere Tiller will be deployed and click Create.
Now, when we provision a Helm chart through the Web Console, it will use Tiller to carry out the installation.
Provision "Redis (Helm)"
Not all Helm charts work out of the box in OpenShift. This is most often related to the underlying container image being run as a non-root user (mongodb for example).
- Here, we will select "Redis (Helm)" from the list of available services in the OpenShift Web Console.
- We will configure "Redis (Helm)" by disabling the
values.yamland click Create.
On success, in our
helm-demo project, we have a functional deployment of Tiller and Redis. We can even use the
helm cli tool:
$ helm version --short --tiller-namespace helm-demo
$ helm list -a --tiller-namespace helm-demo
NAME REVISION UPDATED STATUS CHART NAMESPACE
helm-141aff18 1 Tue Jun 19 10:36:01 2018 DEPLOYED redis-3.4.2 helm-demo
In this post we have shown that given a Helm chart repository, we can simply point the Automation Broker at it to expose Helm charts as services via the Kubernetes Service Catalog. Later, if you wish to modify or extend your Helm cart, you should have a look at Automating Helm Charts with Ansible.