nodes-nodes-opaque-resources-creating.adoc

Creating Opaque Integer Resources

There are two steps required to use opaque integer resources. First, the cluster operator must name and advertise a per-node opaque resource on one or more nodes. Second, application developer must request the opaque resource in pods.

To make opaque integer resources available:

Procedure

1. Allocate the resource and assign a name starting with pod.alpha.kubernetes.io/opaque-int-resource-

2. Advertise a new opaque integer resource by submitting a PATCH HTTP request to the API server that specifies the available quantity in the status.capacity for a node in the cluster.

   For example, the following HTTP request advertises five foo resources on the openshift-node-1 node.

   PATCH /api/v1/nodes/openshift-node-1/status HTTP/1.1
   Accept: application/json
   Content-Type: application/json-patch+json
   Host: openshift-master:8080
   
   [
     {
       "op": "add",
       "path": "/status/capacity/pod.alpha.kubernetes.io~1opaque-int-resource-foo",
       "value": "5"
     }
   ]

   Note	The ~1 in the path is the encoding for the character /. The operation path value in the JSON-Patch is interpreted as a JSON-Pointer. For more details, refer to IETF RFC 6901, section 3.

   After this operation, the node status.capacity includes a new resource. The status.allocatable field is updated automatically with the new resource asynchronously.

   Note	Since the scheduler uses the node status.allocatable value when evaluating pod fitness, there might be a short delay between patching the node capacity with a new resource and the first pod that requests the resource to be scheduled on that node.