Edit/Update a pod's yaml - kubernetes

Question

I have a pod in my EKS cluster and I want to edit it's yaml so that I can change the read-only values from true to false . This way I want to be able to make changes to the pod's system/image (haven't exactly figured out it's name) that at the moment it read-only file system.
Is that possible ? Can I do that ?
I tried copying the current yaml contents and creating a new yaml file with the read-only values setted to false ,in order to use it as a replacement for the current one.
The command I tried to use is:
kubectl apply -f telegraf-new.yaml --namespace examplenamespace -l app=polling-telegraf-s
and the error I get is:
Warning: kubectl apply should be used on resource created by either kubectl create --save-config or kubectl apply
The Pod "polling-telegraf-s-79f44d578f-khdjf" is invalid: spec: Forbidden: pod updates may not change fields other than spec.containers[*].image, spec.initContainers[*].image, spec.activeDeadlineSeconds or spec.tolerations (only additions to existing tolerations)
I am not sure that this is a good way to approach my problem but I spend the last few days researching about it and the results are not so encouraging.
Any help,tip,advice to the correct direction would be appreciated.
Edit:
My yaml from the kubectl get pod --namespace tick -l app=polling-telegraf-s -o yaml is :
apiVersion: v1
items:
- apiVersion: v1
kind: Pod
metadata:
annotations:
checksum/config: 45cc44098254d90e88878e037f6eb5803be739890e26d9070e21ac0c0650debd
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"v1","kind":"Pod","metadata":{"annotations":{"checksum/config":"45cc44098254d90e88878e037f6eb5803be739890e26d9070e21ac0c0650debd","kubernetes.io/psp":"eks.privileged"},"creationTimestamp":"2019-10-30T15:49:57Z","generateName":"polling-telegraf-s-79f44d578f-","labels":{"app":"polling-telegraf-s","pod-template-hash":"79f44d578f"},"name":"polling-telegraf-s-79f44d578f-khdjf","namespace":"tick","ownerReferences":[{"apiVersion":"apps/v1","blockOwnerDeletion":true,"controller":true,"kind":"ReplicaSet","name":"polling-telegraf-s-79f44d578f","uid":"ec1e6988-fb2c-11e9-bdf2-02b7fbdf557a"}],"resourceVersion":"134887","selfLink":"/api/v1/namespaces/tick/pods/polling-telegraf-s-79f44d578f-khdjf","uid":"ec1fa8a5-fb2c-11e9-bdf2-02b7fbdf557a"},"spec":{"containers":[{"image":"telegraf:1.10.3-alpine","imagePullPolicy":"IfNotPresent","name":"polling-telegraf-s","resources":{"limits":{"cpu":"1","memory":"2Gi"},"requests":{"cpu":"100m","memory":"256Mi"}},"terminationMessagePath":"/dev/termination-log","terminationMessagePolicy":"File","volumeMounts":[{"mountPath":"/etc/telegraf","name":"config"},{"mountPath":"/var/run/utmp","name":"varrunutmpro","readOnly":true},{"mountPath":"/var/run/secrets/kubernetes.io/serviceaccount","name":"default-token-htxsr","readOnly":true}]}],"dnsPolicy":"ClusterFirst","enableServiceLinks":true,"nodeName":"ip-192-168-179-5.eu-west-2.compute.internal","priority":0,"restartPolicy":"Always","schedulerName":"default-scheduler","securityContext":{},"serviceAccount":"default","serviceAccountName":"default","terminationGracePeriodSeconds":30,"tolerations":[{"effect":"NoExecute","key":"node.kubernetes.io/not-ready","operator":"Exists","tolerationSeconds":300},{"effect":"NoExecute","key":"node.kubernetes.io/unreachable","operator":"Exists","tolerationSeconds":300}],"volumes":[{"hostPath":{"path":"/var/run/utmp","type":""},"name":"varrunutmpro"},{"configMap":{"defaultMode":420,"name":"polling-telegraf-s"},"name":"config"},{"name":"default-token-htxsr","secret":{"defaultMode":420,"secretName":"default-token-htxsr"}}]},"status":{"conditions":[{"lastProbeTime":null,"lastTransitionTime":"2019-10-30T15:49:57Z","status":"True","type":"Initialized"},{"lastProbeTime":null,"lastTransitionTime":"2019-10-30T15:49:58Z","status":"True","type":"Ready"},{"lastProbeTime":null,"lastTransitionTime":"2019-10-30T15:49:58Z","status":"True","type":"ContainersReady"},{"lastProbeTime":null,"lastTransitionTime":"2019-10-30T15:49:57Z","status":"True","type":"PodScheduled"}],"containerStatuses":[{"containerID":"docker://a66f40111474ea28d1b1b7adf6d9e0278adb6d6aefa23b345cc1559174018f27","image":"telegraf:1.10.3-alpine","imageID":"docker-pullable://telegraf#sha256:9106295bc67459633b4d6151c2e1b9949e501560b2e659fe541bda691c566bcf","lastState":{},"name":"polling-telegraf-s","ready":true,"restartCount":0,"state":{"running":{"startedAt":"2019-10-30T15:49:58Z"}}}],"hostIP":"192.168.179.5","phase":"Running","podIP":"192.168.159.179","qosClass":"Burstable","startTime":"2019-10-30T15:49:57Z"}}
kubernetes.io/psp: eks.privileged
creationTimestamp: "2019-10-30T15:49:57Z"
generateName: polling-telegraf-s-79f44d578f-
labels:
app: polling-telegraf-s
pod-template-hash: 79f44d578f
name: polling-telegraf-s-79f44d578f-khdjf
namespace: tick
ownerReferences:
- apiVersion: apps/v1
blockOwnerDeletion: true
controller: true
kind: ReplicaSet
name: polling-telegraf-s-79f44d578f
uid: ec1e6988-fb2c-11e9-bdf2-02b7fbdf557a
resourceVersion: "409255"
selfLink: /api/v1/namespaces/tick/pods/polling-telegraf-s-79f44d578f-khdjf
uid: ec1fa8a5-fb2c-11e9-bdf2-02b7fbdf557a
spec:
containers:
- image: telegraf:1.10.3-alpine
imagePullPolicy: IfNotPresent
name: polling-telegraf-s
resources:
limits:
cpu: "1"
memory: 2Gi
requests:
cpu: 100m
memory: 256Mi
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
volumeMounts:
- mountPath: /etc/telegraf
name: config
- mountPath: /var/run/utmp
name: varrunutmpro
readOnly: true
- mountPath: /var/run/secrets/kubernetes.io/serviceaccount
name: default-token-htxsr
readOnly: true
dnsPolicy: ClusterFirst
enableServiceLinks: true
nodeName: ip-192-168-179-5.eu-west-2.compute.internal
priority: 0
restartPolicy: Always
schedulerName: default-scheduler
securityContext: {}
serviceAccount: default
serviceAccountName: default
terminationGracePeriodSeconds: 30
tolerations:
- effect: NoExecute
key: node.kubernetes.io/not-ready
operator: Exists
tolerationSeconds: 300
- effect: NoExecute
key: node.kubernetes.io/unreachable
operator: Exists
tolerationSeconds: 300
volumes:
- hostPath:
path: /var/run/utmp
type: ""
name: varrunutmpro
- configMap:
defaultMode: 420
name: polling-telegraf-s
name: config
- name: default-token-htxsr
secret:
defaultMode: 420
secretName: default-token-htxsr
status:
conditions:
- lastProbeTime: null
lastTransitionTime: "2019-10-30T15:49:57Z"
status: "True"
type: Initialized
- lastProbeTime: null
lastTransitionTime: "2019-10-30T15:49:58Z"
status: "True"
type: Ready
- lastProbeTime: null
lastTransitionTime: "2019-10-30T15:49:58Z"
status: "True"
type: ContainersReady
- lastProbeTime: null
lastTransitionTime: "2019-10-30T15:49:57Z"
status: "True"
type: PodScheduled
containerStatuses:
- containerID: docker://a66f40111474ea28d1b1b7adf6d9e0278adb6d6aefa23b345cc1559174018f27
image: telegraf:1.10.3-alpine
imageID: docker-pullable://telegraf#sha256:9106295bc67459633b4d6151c2e1b9949e501560b2e659fe541bda691c566bcf
lastState: {}
name: polling-telegraf-s
ready: true
restartCount: 0
state:
running:
startedAt: "2019-10-30T15:49:58Z"
hostIP: 192.168.179.5
phase: Running
podIP: 192.168.159.179
qosClass: Burstable
startTime: "2019-10-30T15:49:57Z"
kind: List
metadata:
resourceVersion: ""
selfLink: ""
and I want to change the readOnly values from true to false .

Answer 1

You can edit a kubernetes resource yaml using the command kubectl edit [resource] [UID]. For instance, to change the yaml of a pod, you would run kubectl edit $POD_UID
However this won't work in your case because you are editing a mount and that requires the pod to be restarted. In this sense, the best approach would be what you already did. Start by extracting the yaml from the api by running kubectl get pod $POD_UID -o yaml and then editing its content to deploy it again. However as the error depicts, you are not allowed to edit some parts of the yaml. So you have to remove those parts.
Only keep the parts that the log has already pointed to: spec.containers[*].image, spec.initContainers[*].image, spec.activeDeadlineSeconds or spec.tolerations
Otherwise, here are the sections you would have to remove:
metadata:
creationTimestamp: 2019-11-01T13:22:50Z
generateName:
ownerReferences:
- apiVersion: apps/v1
blockOwnerDeletion: true
controller: true
kind: ReplicaSet
name:
uid: 947fb7b7-f1ab-11e9-adfb-42010a8001b2
resourceVersion: "103002009"
selfLink:
uid: b3f96ba4-fcaa-11e9-adfb-42010a8001b2
spec:
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
volumeMounts:
- mountPath: /var/run/secrets/kubernetes.io/serviceaccount
name: default-token-ff27n
readOnly: true
nodeName:
priority: 0
schedulerName: default-scheduler
securityContext: {}
serviceAccount: default
serviceAccountName: default
terminationGracePeriodSeconds: 30
tolerations:
- effect: NoExecute
key: node.kubernetes.io/not-ready
operator: Exists
tolerationSeconds: 300
- effect: NoExecute
key: node.kubernetes.io/unreachable
operator: Exists
tolerationSeconds: 300
volumes:
- name: default-token-ff27n
secret:
defaultMode: 420
secretName: default-token-ff27n
status:
conditions:
- lastProbeTime: null
lastTransitionTime: 2019-11-01T13:22:50Z
status: "True"
type: Initialized
- lastProbeTime: null
lastTransitionTime: 2019-11-01T13:22:55Z
status: "True"
type: Ready
- lastProbeTime: null
lastTransitionTime: null
status: "True"
type: ContainersReady
- lastProbeTime: null
lastTransitionTime: 2019-11-01T13:22:50Z
status: "True"
type: PodScheduled
containerStatuses:
- containerID:
image:
imageID:
lastState: {}
name: proxy
ready: true
restartCount: 0
state:
running:
startedAt: 2019-11-01T13:22:55Z
hostIP:
phase: Running
podIP:
qosClass: Burstable
startTime: 2019-11-01T13:22:50Z

Answer 2

You can edit pod yaml on the fly using kubectl edit pods <pod-name>.
You have to keep in mind that there are fields which will not be allowed to be edited while pod is scheduled, this is mentioned in your error message.
I think you should first remove the pod and apply the new yaml file.