Kubernetes - How to know latest supported API version

Question

Is there a table that will tell me which set of API versions I should be using, given a k8s cluster version? Kubernetes docs always assume I always have a nice, up-to-date cluster (1.12 at time of writing) but platform providers don't always live on this bleeding edge so it can get frustrating quite quickly.

Better yet, is there a kubectl command I can run that will let me cluster tell me each resource type and its latest supported API version?

Answer 1

You can use Move2Kube and do move2kube collect with the Kubernetes cluster in context to get all kind versions supported by the cluster. It gives an ordered list of all versions supported by a kind in an order going from newest to oldest.

It will give you the following information:

apiVersion: move2kube.konveyor.io/v1alpha1
kind: ClusterMetadata
metadata:
  name: IBM-IKS
spec:
  storageClasses:
    - default
    - ibmc-block-bronze
    - ibmc-block-custom
    - ibmc-block-gold
    - ibmc-block-retain-bronze
    - ibmc-block-retain-custom
    - ibmc-block-retain-gold
    - ibmc-block-retain-silver
    - ibmc-block-silver
    - ibmc-file-bronze
    - ibmc-file-bronze-gid
    - ibmc-file-custom
    - ibmc-file-gold
    - ibmc-file-gold-gid
    - ibmc-file-retain-bronze
    - ibmc-file-retain-custom
    - ibmc-file-retain-gold
    - ibmc-file-retain-silver
    - ibmc-file-silver
    - ibmc-file-silver-gid
  apiKindVersionMap:
    APIService:
      - apiregistration.k8s.io/v1
    BGPConfiguration:
      - crd.projectcalico.org/v1
    BGPPeer:
      - crd.projectcalico.org/v1
    Binding:
      - v1
    BlockAffinity:
      - crd.projectcalico.org/v1
    CSIDriver:
      - storage.k8s.io/v1
      - storage.k8s.io/v1beta1
    CSINode:
      - storage.k8s.io/v1
      - storage.k8s.io/v1beta1
    CatalogSource:
      - operators.coreos.com/v1alpha1
    CertificateSigningRequest:
      - certificates.k8s.io/v1beta1
    ClusterInformation:
      - crd.projectcalico.org/v1
    ClusterRole:
      - rbac.authorization.k8s.io/v1
      - rbac.authorization.k8s.io/v1beta1
    ClusterRoleBinding:
      - rbac.authorization.k8s.io/v1
      - rbac.authorization.k8s.io/v1beta1
    ClusterServiceVersion:
      - operators.coreos.com/v1alpha1
    ComponentStatus:
      - v1
    ConfigMap:
      - v1
    ControllerRevision:
      - apps/v1
    CronJob:
      - batch/v1beta1
      - batch/v2alpha1
    CustomResourceDefinition:
      - apiextensions.k8s.io/v1
    DaemonSet:
      - apps/v1
    Deployment:
      - apps/v1
    EndpointSlice:
      - discovery.k8s.io/v1beta1
    Endpoints:
      - v1
    Event:
      - events.k8s.io/v1beta1
      - v1
    FelixConfiguration:
      - crd.projectcalico.org/v1
    GlobalNetworkPolicy:
      - crd.projectcalico.org/v1
    GlobalNetworkSet:
      - crd.projectcalico.org/v1
    HorizontalPodAutoscaler:
      - autoscaling/v1
      - autoscaling/v2beta1
      - autoscaling/v2beta2
    HostEndpoint:
      - crd.projectcalico.org/v1
    IPAMBlock:
      - crd.projectcalico.org/v1
    IPAMConfig:
      - crd.projectcalico.org/v1
    IPAMHandle:
      - crd.projectcalico.org/v1
    IPPool:
      - crd.projectcalico.org/v1
    Ingress:
      - networking.k8s.io/v1
      - networking.k8s.io/v1beta1
      - extensions/v1beta1
    IngressClass:
      - networking.k8s.io/v1
      - networking.k8s.io/v1beta1
    InstallPlan:
      - operators.coreos.com/v1alpha1
    Job:
      - batch/v1
    KubeControllersConfiguration:
      - crd.projectcalico.org/v1
    Lease:
      - coordination.k8s.io/v1beta1
      - coordination.k8s.io/v1
    LimitRange:
      - v1
    LocalSubjectAccessReview:
      - authorization.k8s.io/v1
      - authorization.k8s.io/v1beta1
    MutatingWebhookConfiguration:
      - admissionregistration.k8s.io/v1beta1
      - admissionregistration.k8s.io/v1
    Namespace:
      - v1
    NetworkPolicy:
      - networking.k8s.io/v1
    NetworkSet:
      - crd.projectcalico.org/v1
    Node:
      - v1
    Operator:
      - operators.coreos.com/v1
    OperatorGroup:
      - operators.coreos.com/v1
    PersistentVolume:
      - v1
    PersistentVolumeClaim:
      - v1
    Pod:
      - v1
    PodDisruptionBudget:
      - policy/v1beta1
    PodSecurityPolicy:
      - policy/v1beta1
    PodTemplate:
      - v1
    PriorityClass:
      - scheduling.k8s.io/v1beta1
      - scheduling.k8s.io/v1
    RBACSync:
      - ibm.com/v1alpha1
    ReplicaSet:
      - apps/v1
    ReplicationController:
      - v1
    ResourceQuota:
      - v1
    Role:
      - rbac.authorization.k8s.io/v1
      - rbac.authorization.k8s.io/v1beta1
    RoleBinding:
      - rbac.authorization.k8s.io/v1
      - rbac.authorization.k8s.io/v1beta1
    Secret:
      - v1
    SelfSubjectAccessReview:
      - authorization.k8s.io/v1
      - authorization.k8s.io/v1beta1
    SelfSubjectRulesReview:
      - authorization.k8s.io/v1
      - authorization.k8s.io/v1beta1
    Service:
      - v1
    ServiceAccount:
      - v1
    StatefulSet:
      - apps/v1
    StorageClass:
      - storage.k8s.io/v1
      - storage.k8s.io/v1beta1
    SubjectAccessReview:
      - authorization.k8s.io/v1
      - authorization.k8s.io/v1beta1
    Subscription:
      - operators.coreos.com/v1alpha1
    TokenReview:
      - authentication.k8s.io/v1
      - authentication.k8s.io/v1beta1
    ValidatingWebhookConfiguration:
      - admissionregistration.k8s.io/v1beta1
      - admissionregistration.k8s.io/v1
    VolumeAttachment:
      - storage.k8s.io/v1
      - storage.k8s.io/v1beta1

Answer 2

For getting a list of all the resource types and their latest supported version, run the following:

for kind in `kubectl api-resources | tail +2 | awk '{ print $1 }'`; do kubectl explain $kind; done | grep -e "KIND:" -e "VERSION:"

It should produce output like

KIND:     Binding
VERSION:  v1
KIND:     ComponentStatus
VERSION:  v1
KIND:     ConfigMap
VERSION:  v1
KIND:     Endpoints
VERSION:  v1
KIND:     Event
VERSION:  v1
...

As @Rico mentioned, they key is in the kubectl explain command. This may be a little fragile since it depends on the format of the printed output, but it works for kubernetes 1.9.6

Also, the information can be gathered in a less efficient way from the kubernetes API docs (with links for each version) found here - https://kubernetes.io/docs/reference/#api-reference

Answer 3

You can use a tool - kubepug as a pre-upgrade check to find out what changed in a given Kubernetes version if you were to upgrade your cluster to that version. Link - https://github.com/rikatz/kubepug

Answer 4

For kubernetes-1.17.x (different format from what posted above)

for i in `kubectl api-resources | grep -v KIND | awk '{print $NF}'`;do kubectl explain ${i} | grep -e "KIND:" -e "VERSION:"; echo '----'; done

will show api for each kind

Answer 5

I think kubectl api-versions is a simpler alternative:

 kubectl api-versions
admissionregistration.k8s.io/v1beta1
apiextensions.k8s.io/v1beta1
apiregistration.k8s.io/v1
apiregistration.k8s.io/v1beta1
apps/v1
apps/v1beta1
apps/v1beta2
authentication.k8s.io/v1
authentication.k8s.io/v1beta1
authorization.k8s.io/v1
authorization.k8s.io/v1beta1
autoscaling/v1
autoscaling/v2beta1
autoscaling/v2beta2
batch/v1
batch/v1beta1
certificates.k8s.io/v1beta1
coordination.k8s.io/v1
coordination.k8s.io/v1beta1
events.k8s.io/v1beta1
extensions/v1beta1
networking.k8s.io/v1
networking.k8s.io/v1beta1
node.k8s.io/v1beta1
policy/v1beta1
rbac.authorization.k8s.io/v1
rbac.authorization.k8s.io/v1beta1
scheduling.k8s.io/v1
scheduling.k8s.io/v1beta1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1

Answer 6

That would be the kubectl explain <resource> command. For example for pods:

$ kubectl explain pod
KIND:     Pod
VERSION:  v1   <==  API version

DESCRIPTION:
     Pod is a collection of containers that can run on a host. This resource is
     created by clients and scheduled onto hosts.

FIELDS:
   apiVersion   <string>
     APIVersion defines the versioned schema of this representation of an
     object. Servers should convert recognized schemas to the latest internal
     value, and may reject unrecognized values. More info:
     https://git.k8s.io/community/contributors/devel/api-conventions.md#resources

...

Similarly for deployments:

$ kubectl explain deploy
KIND:     Deployment
VERSION:  extensions/v1beta1 <== API Version

DESCRIPTION:
     DEPRECATED - This group version of Deployment is deprecated by
     apps/v1beta2/Deployment. See the release notes for more information.
     Deployment enables declarative updates for Pods and ReplicaSets.

FIELDS:
   apiVersion   <string>
     APIVersion defines the versioned schema of this representation of an
     object. Servers should convert recognized schemas to the latest internal
     value, and may reject unrecognized values. More info:
     https://git.k8s.io/community/contributors/devel/api-conventions.md#resources
...

Also, here's the v1.12 API reference for example.