kubernetes/helm/README.adoc

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= Building Kubernetes Kudu Cluster Using Helm Chart

NOTE: All of this work is experimental and subject to change or removal.

== Getting Started

Helm — The package manager for Kubernetes. Helps to define, install, and
upgrade Kubernetes applications.

NOTE: Read more about Helm here https://helm.sh/docs/using_helm/#quickstart

The below instructions rely on having Kudu Docker images built.

==== System Requirements

    kubectl
    minikube or kubeadm
    docker
    helm

=== Using Helm v3

. Deploy a Kubernetes cluster with a cluster manager choice. For the sake of
  local development, `minikube` is a fine choice:
+
----
$ minikube start
----

. If you have made changes to your Docker images, or would otherwise like to
  use local images rather than those found on DockerHub, ensure your Kubernetes
  cluster can access your desired Docker images.
+
----
$ minikube cache add apache/kudu:latest
----

. Install the `apache-kudu` Helm Chart. Optionally supply an edited
  `values.yaml` file. This deploys a Kudu cluster using the `minikube`
  container.
+
----
$ helm install -f kudu/values.yaml apache-kudu ./kudu
----

. Verify the cluster is running and view its logs.
+
----
$ kubectl get pods
NAME             READY   STATUS    RESTARTS   AGE
kudu-master-0    1/1     Running   0          108s
kudu-master-1    1/1     Running   0          108s
kudu-master-2    1/1     Running   0          108s
kudu-tserver-0   1/1     Running   0          108s
kudu-tserver-1   1/1     Running   0          108s
kudu-tserver-2   1/1     Running   0          108s

$ kubectl logs kudu-tserver-1
I0730 00:36:07.404302     1 tablet_server_runner.cc:78] Tablet server non-default flags:
--use_hybrid_clock=false
--fs_data_dirs=/mnt/disk1,/mnt/disk2,/mnt/disk3,/mnt/disk4
--fs_wal_dir=/mnt/disk0
--webserver_doc_root=/opt/kudu/www
--tserver_master_addrs=kudu-master-0.kudu-masters.default.svc.cluster.local,kudu-master-1.kudu-masters.default.svc.cluster.local,kudu-master-2.kudu-masters.default.svc.cluster.local
--heap_profile_path=/tmp/kudu.1
--stderrthreshold=0

Tablet server version:
...
----

. To stop Kudu, uninstall the Helm Chart.
+
----
$ helm uninstall apache-kudu
----

=== Using Helm v2

==== Creating Namespace

    $ kubectl create -f ../namespace.yaml

==== Creating ServiceAccount And Role Binding (RBAC)

    $ kubectl create -f kudu-rbac.yaml

==== Initializing Helm Tiller

    $ helm init --service-account kudu-helm --tiller-namespace apache-kudu --upgrade --wait

Check if tiller is initialized and you should not see any authorization errors.

    $ helm ls --namespace apache-kudu --tiller-namespace apache-kudu

==== Helm Launch Kudu cluster

    $ helm install kudu --namespace apache-kudu --name apache-kudu --tiller-namespace apache-kudu --wait

    $ helm install kudu -f kudu-expose-all.yaml --namespace apache-kudu --name apache-kudu --tiller-namespace apache-kudu --wait

You should see below output on stdout

```
NAME:   apache-kudu
LAST DEPLOYED: Fri Jun  7 12:03:47 2019
NAMESPACE: apache-kudu
STATUS: DEPLOYED

RESOURCES:
==> v1/Pod(related)
NAME            READY  STATUS   RESTARTS  AGE
kudu-master-0   1/1    Running  0         12s
kudu-master-1   1/1    Running  0         12s
kudu-master-2   1/1    Running  0         12s
kudu-tserver-0  1/1    Running  0         12s
kudu-tserver-1  1/1    Running  0         12s

==> v1/Service
NAME                  TYPE       CLUSTER-IP     EXTERNAL-IP  PORT(S)                        AGE
kudu-master-service   NodePort   10.100.28.117  <none>       8051:31198/TCP,8050:31182/TCP  12s
kudu-masters          ClusterIP  None           <none>       8051/TCP,8050/TCP              12s
kudu-tserver-service  NodePort   10.103.171.31  <none>       7051:30967/TCP,7050:32543/TCP  12s
kudu-tservers         ClusterIP  None           <none>       7051/TCP,7050/TCP              12s

==> v1/StatefulSet
NAME          READY  AGE
kudu-master   3/3    12s
kudu-tserver  2/2    12s

==> v1beta1/PodDisruptionBudget
NAME              MIN AVAILABLE  MAX UNAVAILABLE  ALLOWED DISRUPTIONS  AGE
kudu-tserver-pdb  N/A            1                1                    12s
```

==== Port Forward The Kudu Master UI

    $ kubectl port-forward kudu-master-0 8051 -n apache-kudu
    OR
    $ minikube service kudu-master-service --url -n apache-kudu

==== Destroy The Kudu Cluster

    $ helm del --purge apache-kudu --tiller-namespace apache-kudu

==== Display Kudu Master Logs:

    $ kubectl logs kudu-master-0 --namespace apache-kudu

=== Testing Helm Charts

    # helm-template : it will render chart templates locally and display the output.
    $ helm template kudu

    # To render just one template in a chart
    $ helm template kudu -x templates/kudu-service.yaml

    # helm lint: examines a chart for possible issues, useful to validate chart dependencies.
    $ helm lint kudu --namespace apache-kudu --tiller-namespace apache-kudu

    # The argument this command takes is the name of a deployed release.
    # The tests to be run are defined in the chart that was installed.
    $ helm test apache-kudu --tiller-namespace apache-kudu