A mutating admission controller webhook doesn't remove object fields
when instructed to.
E.g. when the JSON patch
[
{"op": "remove", "path": "/spec/containers/0/resources/limits/fpga-arria10"},
{"op": "add", "path": "/spec/containers/0/resources/limits/fpga-interface-id-524abcf", "value": 1}
]
is applied to this pod
apiVersion: v1
kind: Pod
metadata:
name: test-pod
spec:
restartPolicy: Never
containers:
-
name: test-pod-container
image: ubuntu:bionic
imagePullPolicy: IfNotPresent
command: [ "ls", "-l", "/" ]
resources:
limits:
fpga-arria10: 1
in order to replace the resource name "fpga-arria10" with something understandable
by the device plugin the resulting pod spec still contains the old field plus
a new one. The resulting pod looks like
apiVersion: v1
kind: Pod
metadata:
name: test-pod
spec:
restartPolicy: Never
containers:
-
name: test-pod-container
image: ubuntu:bionic
imagePullPolicy: IfNotPresent
command: [ "ls", "-l", "/" ]
resources:
limits:
fpga-arria10: 1
fpga-interface-id-524abcf: 1
The patch unmarshals patched JSON into a new empty object instead of
existing one. Otherwise JSON unmarshaling reuses existing maps, keeping
existing entries as specified in the "encoding/json" standard package.
Kubernetes-commit: 4a72e17bd227b79ed89981735691af3601043bf9
d51f943047