Kubernetes API - deep dive into the kube-apiserver

Kubernetes APIDEEP DIVE INTO THE APISERVER

Dr. StefanSchimansk i , sttts@redhat .com

RestfulhttpAPI

//version

/api/api/v1/pods/api/v1/pods/status

/apis/apis/batch/apis/batch/v1alpha1/apis/batch/v1alpha1/jobs/apis/batch/v1alpha1/cronjobs/apis/batch/v1beta1/apis/batch/v1beta1/jobs

kube-apiserver $kubectl create -ffoo.yaml

RestfulhttpAPI

//version



RestfulhttpAPI

//version



RestfulhttpAPI

//version



/apis/batch/v2alpha1/jobs

GroupVersionResourceHTTPpaths:

InGo: gvk :=schema.GroupVersionKind{Group:“batch“,Version:“v2alpha1“,Kind:“Job“}obj :=api.Schema.New(gvk)codec :=api.Codecs.LegacyCodec(gvk.GroupVersion())codec.Decode(reqBody,gvk,obj)

typeJob struct {metav1.TypeMetametav1.ObjectMetaSpec JobSpecStatusJobStatus

}pkg/apis/batch/v2alpha1/types.go

typeTypeMeta struct {KindstringAPIVersion string

}

typeObjectMeta struct {Namestring...

}

RestfulhttpAPI

//version



MaxInFlightLimit

Timeo

utForNon

LongRu

nningReq

uests

PanicRe

covery

CORS

Authen

tication

Audit

Impe

rson

ation

Authoriza

tion

k8s.io/apiserver/pkg/server.DefaultBuildHandlerChain

„Filters“

k8s.io/apiserver/pkg/server/routes/index.go – /k8s.io/apiserver/pkg/server/routes/version.go – /versionk8s.io/apiserver/pkg/server/routes/swagger.go – /swaggerapik8s.io/apiserver/pkg/server/routes/openapi.go – /swagger.json

„Routes“

mux

k8s.io/apiserver/pkg/endpoints.APIGroupVersion.InstallREST

AddSupportedResourcesWebService – /apis/batch/v2alpha1

k8s.io/apiserver/pkg/endpoints.APIInstaller.Install

/apis/batch/v2alpha1/jobs/apis/batch/v2alpha1/cronjobs...

With

Requ

estIn

fo

ctx.RequestInfo

RestfulhttpAPI

mux

k8s.io/apiserver/pkg/endpoints.APIGroupVersion.InstallREST

AddSupportedResourcesWebService – /apis/batch/v2alpha1

k8s.io/apiserver/pkg/endpoints.APIInstaller.Install/apis/batch/v2alpha1/jobs/apis/batch/v2alpha1/cronjobs...

pkg/apis/batchtype Jobsstruct

pkg/apis/batch/v2alpha1type Jobsstruct

api.Schemek8s.io/apiserver

pkg/api api.Scheme.Convert(&internalJob,&v2alohaJob)

/apis/batch/v2alpha1/jobsGETPUTPOSTDELETE...

/status/scale/proxy...

subresources

RestfulhttpAPI

mux

pkg/apis/batchtype Jobsstruct

pkg/apis/batch/v2alpha1type Jobsstruct

api.Scheme api.Scheme.Convert(&job,&v1job)

POST/apis/batch/v2alpha1/jobs

k8s.io/apiserverpkg/endpoints/handlers.CreateNamedResource

binaryJSON

payload

Gostructv2alpha1.Job

HTTPRequest

Gostructinternal.Job

Storek8s.io/apiserver

pkg/registry/generic

Storagek8s.io/apiserverpkg/storage/etcd3

ProtoBufJob

Gostructv2alpha1.Job

etcd

type Scheme struct• AddKnownTypes(gv, obj Object) • Default(src Object)• Copy(src Object) Object• Convert(in, out interface{})• New(gvk) Object

ApiGrouppkg/apis/batchpkg/apis/batch/v1pkg/apis/batch/v2alpha1pkg/apis/batch/register.gopgk/apis/batch/install

GroupVersionKindResource

type Object interface• GetObjectKind() string

client-go/pkg/api.Schemeclient-go/pkg/api.Codecs

Discoverytype APIGroupList structtype APIVersions structtype APIResourceList struct

GroupVersionKind „gvk“GroupVersionResource

Unversioned typesUnstructuredList

Registry / Storagetype Storage interfacetype Lister interfacetype Updater interfacetype Getter interfacetype Deleter interface....

deepcopy-genconversion-gendefaulting-gen

Code Generation

type OwnerReference structtype ObjectReference structtype TypeMeta structtype ObjectMeta struct

Meta

api.Schemeapi.Codecsapi.Registryapi.GroupFactoryRegistry

Globals

Software

Kubernetes API - deep dive into the kube-apiserver