how do I enable mount propagation in Rancher - Kubernetes feature gates?

How can I enable feature gates for my cluster in Rancher 2.0? I am in need of enabling the --feature-gates MountPropagation=true. This will enable me to use storage solutions like StorageOS, CephFS, etc

There are 2 use cases here :

1. If the Rancher is setup already and running?
2. If I am setting up the cluster from scratch?

Hello and hope this helps someone, After much googling and help from awesome people at Rancher I got the solution for this. Here is what you can do to set the feature gates flags for the Kubernetes engine RKE.

step 1: Open Rancher2.0 UI

step 2: View cluster in API

step 3: Click edit and modify the rancherKubernetesEngineConfig input box

• Find the services key.

• Then add extra args for kubelet in below format

  "services": {
  "etcd": { "type": "/v3/schemas/etcdService" },
  "kubeApi": {
      "podSecurityPolicy": false,
      "type": "/v3/schemas/kubeAPIService",
      "extraArgs": { "feature-gates": "PersistentLocalVolumes=true, VolumeScheduling=true,MountPropagation=true" }
  },
  "kubeController": { "type": "/v3/schemas/kubeControllerService" },
  "kubelet": {
      "failSwapOn": false,
      "type": "/v3/schemas/kubeletService",
      "extraArgs": { "feature-gates": "PersistentLocalVolumes=true, VolumeScheduling=true,MountPropagation=true" }
  }
  

step 4: Click show request .. you get a curl command and json request.

step 5: Verify the request body data which will be shown.

step 6: Make sure the key's which are not applicable are set to null. e.g amazonElasticContainerServiceConfig, azureKubernetesServiceConfig, googleKubernetesEngineConfig all need to null for me.

step 7: Click send request

You should get a response with status code 201. And your cluster will start updating. You can verify that your cluster RKE has updated by viewing the Cluster in API again.