Update magnum cloud provider README for helm installation

Author: tghartland

cluster-autoscaler/cloudprovider/magnum/README.md

@@ -47,6 +47,30 @@ to match your cluster.
 | --nodes                     | Used to select a specific node group to autoscale and constrain its node count. Of the form `min:max:NodeGroupName`. Can be used multiple times. |
 | --node-group-auto-discovery | See below.                                                                                                                                       |
 
+#### Deployment with helm
+
+Alternatively, the autoscaler can be deployed with the cluster autoscaler helm chart.
+A minimal values.yaml file looks like:
+
+```yaml
+cloudProvider: "magnum"
+
+magnumClusterName: "cluster name or ID"
+
+autoscalingGroups:
+- name: default-worker
+  maxSize: 5
+  minSize: 1
+
+cloudConfigPath: "/etc/kubernetes/cloud-config"
+```
+
+For running on the master node and other suggested settings, see
+[examples/values-example.yaml](examples/values-example.yaml).
+To deploy with node group autodiscovery (for cluster autoscaler v1.19+), see
+[examples/values-autodiscovery.yaml](examples/values-autodiscovery.yaml).
+
+
 ## Node group auto discovery
 
 Instead of using `--nodes` to select specific node groups by name,

cluster-autoscaler/cloudprovider/magnum/examples/values-autodiscovery.yaml

@@ -0,0 +1,29 @@
+cloudProvider: "magnum"
+
+autoDiscovery:
+  clusterName: "cluster name or ID"
+  roles:
+  - worker
+  - autoscaling
+
+image:
+  repository: docker.io/openstackmagnum/cluster-autoscaler
+  tag: v1.19.0
+
+nodeSelector:
+  node-role.kubernetes.io/master: ""
+
+tolerations:
+- key: CriticalAddonsOnly
+  value: "True"
+  effect: NoSchedule
+- key: dedicated
+  value: "master"
+  effect: NoSchedule
+- key: node-role.kubernetes.io/master
+  effect: NoSchedule
+
+cloudConfigPath: /etc/kubernetes/cloud-config
+
+extraArgs:
+  v: 2

cluster-autoscaler/cloudprovider/magnum/examples/values-example.yaml

@@ -0,0 +1,30 @@
+cloudProvider: "magnum"
+
+magnumClusterName: "cluster name or ID"
+
+autoscalingGroups:
+- name: default-worker
+  maxSize: 5
+  minSize: 1
+
+image:
+  repository: docker.io/openstackmagnum/cluster-autoscaler
+  tag: v1.19.0
+
+nodeSelector:
+  node-role.kubernetes.io/master: ""
+
+tolerations:
+- key: CriticalAddonsOnly
+  value: "True"
+  effect: NoSchedule
+- key: dedicated
+  value: "master"
+  effect: NoSchedule
+- key: node-role.kubernetes.io/master
+  effect: NoSchedule
+
+cloudConfigPath: "/etc/kubernetes/cloud-config"
+
+extraArgs:
+  v: 2

cluster-autoscaler/cloudprovider/magnum/examples/values-minimal.yaml

@@ -0,0 +1,10 @@
+cloudProvider: "magnum"
+
+magnumClusterName: "cluster name or ID"
+
+autoscalingGroups:
+- name: default-worker
+  maxSize: 5
+  minSize: 1
+
+cloudConfigPath: "/etc/kubernetes/cloud-config"