how to get objects's metadata name in kubernetes - rest

Question

I can get all the things of a list of objects, such as Secrets and ConfigMaps.
{
"kind": "SecretList",
"apiVersion": "v1",
"metadata": {
"selfLink": "/api/v1/namespaces/kube-system/secrets",
"resourceVersion": "499638"
},
"items": [{
"metadata": {
"name": "aaa",
"namespace": "kube-system",
"selfLink": "/api/v1/namespaces/kube-system/secrets/aaa",
"uid": "96b0fbee-f14c-423d-9734-53fed20ae9f9",
"resourceVersion": "1354",
"creationTimestamp": "2020-02-24T11:20:23Z"
},
"data": "aaa"
}]
}
but I only want the name list, for this example :"aaa". Is there any way?

Answer 1

Yes, you can achieve it by using jsonpath output. Note that the specification you posted will look quite differently once applied. It will create one Secret object in your kube-system namespace and when you run:
$ kubectl get secret -n kube-system aaa -o json
the output will look similar to the following:
{
"apiVersion": "v1",
"kind": "Secret",
"metadata": {
"creationTimestamp": "2020-02-25T11:08:21Z",
"name": "aaa",
"namespace": "kube-system",
"resourceVersion": "34488887",
"selfLink": "/api/v1/namespaces/kube-system/secrets/aaa",
"uid": "229edeb3-57bf-11ea-b366-42010a9c0093"
},
"type": "Opaque"
}
To get only the name of your Secret you need to run:
kubectl get secret aaa -n kube-system -o jsonpath='{.metadata.name}'

Answer 2

i think this should work.
kubectl get secretlist -o=jsonpath="{.items[*].metadata.name]}" | grep -v HEAD | head -n1
check link in the below for more info.
https://kubernetes.io/docs/reference/kubectl/jsonpath/