This assumes you have installed the tridentctl command line tool. 

The tridentctl get storageclass command can be used to list the Trident Storage Classes. In this example, the Trident backend is running on an OpenShift pod in the "trident" project (namespace).

~]# tridentctl get storageclass --namespace trident
+-----------------------+
|     NAME              |
+-----------------------+
| trident-storage-class |
+-----------------------+

Or, if running Trident in an OpenShift pod, the oc get pods command can be used to list the Trident pods.

~]$ oc get pods --namespace trident
NAME                           READY   STATUS    RESTARTS   AGE
trident-csi-28x7h              2/2     Running   0          7m12s
trident-csi-5fb5bb4886-gxh4s   6/6     Running   0          6m34s
trident-csi-8rmvd              2/2     Running   0          7m12s
trident-csi-cfdcq              2/2     Running   0          7m13s
trident-csi-gdm6n              2/2     Running   0          7m12s
trident-csi-mr682              2/2     Running   0          7m12s
trident-csi-qdr6v              2/2     Running   0          7m12s
trident-csi-rmvxx              2/2     Running   0          7m12s
trident-csi-tspz5              2/2     Running   0          7m12s
trident-csi-xfscd              2/2     Running   0          7m12s

And then the oc exec command can be used to issue the tridentctl get storageclass command in the container.

~]$ oc exec trident-csi-5fb5bb4886-gxh4s --container trident-main --namespace trident -- tridentctl get storageclass
+-----------------------+
|     NAME              |
+-----------------------+
| trident-storage-class |
+-----------------------+