Drop the support for CRI v1alpha2

Kubernetes has dropped the support for CRI v1alpha2 in Kubernetes v1.26: kubernetes/kubernetes PR 110618

Kubernetes v1.25, the last release to support v1alpha2, has already reached the EOL:
https://kubernetes.io/releases/patch-releases/#non-active-branch-history

Fix issue 333

Signed-off-by: Akihiro Suda <[email protected]>

Author: AkihiroSuda

backend/daemon.go

@@ -25,7 +25,6 @@ import (
 	"github.com/sirupsen/logrus"
 	"google.golang.org/grpc"
 	runtimeapi "k8s.io/cri-api/pkg/apis/runtime/v1"
-	runtimeapi_alpha "k8s.io/cri-api/v1alpha2/pkg/apis/runtime/v1alpha2"
 	"k8s.io/kubernetes/pkg/kubelet/util"
 
 	"github.com/Mirantis/cri-dockerd/core"
@@ -87,10 +86,6 @@ func (s *CriDockerService) Start() error {
 	runtimeapi.RegisterRuntimeServiceServer(s.server, s.service)
 	runtimeapi.RegisterImageServiceServer(s.server, s.service)
 
-	as := core.NewDockerServiceAlpha(s.service)
-	runtimeapi_alpha.RegisterRuntimeServiceServer(s.server, as)
-	runtimeapi_alpha.RegisterImageServiceServer(s.server, as)
-
 	go func() {
 		if err := s.server.Serve(l); err != nil {
 			logrus.Error(err, "Failed to serve connections from cri-dockerd")

config/constants.go

@@ -168,6 +168,4 @@ const (
 
 	// CRIVersion is the latest CRI version supported by the CRI plugin.
 	CRIVersion = "v1"
-	// CRIVersionAlpha is the alpha version of CRI supported by the CRI plugin.
-	CRIVersionAlpha = "v1alpha2"
 )

core/docker_service.go

@@ -45,7 +45,6 @@ import (
 
 	v1 "k8s.io/api/core/v1"
 	runtimeapi "k8s.io/cri-api/pkg/apis/runtime/v1"
-	runtimeapi_alpha "k8s.io/cri-api/v1alpha2/pkg/apis/runtime/v1alpha2"
 )
 
 const (
@@ -74,12 +73,6 @@ const (
 	defaultCgroupDriver = "cgroupfs"
 )
 
-// v1AlphaCRIService provides the interface necessary for cri.v1alpha2
-type v1AlphaCRIService interface {
-	runtimeapi_alpha.RuntimeServiceServer
-	runtimeapi_alpha.ImageServiceServer
-}
-
 // CRIService includes all methods necessary for a CRI backend.
 type CRIService interface {
 	runtimeapi.RuntimeServiceServer
@@ -288,17 +281,6 @@ type dockerService struct {
 	cleanupInfosLock      sync.RWMutex
 }
 
-type dockerServiceAlpha struct {
-	ds DockerService
-
-	// This handles unimplemented methods unless cri-dockerd overrides them
-	runtimeapi_alpha.UnimplementedRuntimeServiceServer
-}
-
-func NewDockerServiceAlpha(ds DockerService) v1AlphaCRIService {
-	return &dockerServiceAlpha{ds: ds}
-}
-
 // Version returns the runtime name, runtime version and runtime API version
 func (ds *dockerService) Version(
 	_ context.Context,
@@ -316,22 +298,6 @@ func (ds *dockerService) Version(
 	}, nil
 }
 
-func (ds *dockerService) AlphaVersion(
-	_ context.Context,
-	r *runtimeapi.VersionRequest,
-) (*runtimeapi_alpha.VersionResponse, error) {
-	v, err := ds.getDockerVersion()
-	if err != nil {
-		return nil, err
-	}
-	return &runtimeapi_alpha.VersionResponse{
-		Version:           kubeAPIVersion,
-		RuntimeName:       dockerRuntimeName,
-		RuntimeVersion:    v.Version,
-		RuntimeApiVersion: config.CRIVersionAlpha,
-	}, nil
-}
-
 // getDockerVersion gets the version information from docker.
 func (ds *dockerService) getDockerVersion() (*dockertypes.Version, error) {
 	res, err := ds.systemInfoCache.Memoize("docker_version", systemInfoCacheMinTTL, func() (interface{}, error) {