resource.go

package volumebindingmigration

import (
	"bytes"
	"context"

	providerv1alpha1 "github.com/giantswarm/apiextensions/v3/pkg/apis/provider/v1alpha1"
	"github.com/giantswarm/errors/tenant"
	"github.com/giantswarm/k8sclient/v5/pkg/k8sclient"
	"github.com/giantswarm/microerror"
	"github.com/giantswarm/micrologger"
	"github.com/giantswarm/tenantcluster/v3/pkg/tenantcluster"
	storagev1 "k8s.io/api/storage/v1"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/client-go/rest"
	ctrl "sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/yaml"

	"github.com/giantswarm/azure-operator/v5/service/controller/key"
	"github.com/giantswarm/azure-operator/v5/service/controller/templates/ignition"
)

const (
	// Name is the identifier of the resource.
	Name = "volumebindingmigration"

	provisionerAzureFile = "kubernetes.io/azure-file"
)

type Config struct {
	Logger                   micrologger.Logger
	TenantRestConfigProvider *tenantcluster.TenantCluster
}

// Resource ensures that existing StorageClasses use `WaitForFirstConsumer`
// bind mode.
type Resource struct {
	logger                   micrologger.Logger
	tenantRestConfigProvider *tenantcluster.TenantCluster
}

func New(config Config) (*Resource, error) {
	if config.Logger == nil {
		return nil, microerror.Maskf(invalidConfigError, "%T.Logger must not be empty", config)
	}
	if config.TenantRestConfigProvider == nil {
		return nil, microerror.Maskf(invalidConfigError, "%T.TenantRestConfigProvider must not be empty", config)
	}

	r := &Resource{
		logger:                   config.Logger,
		tenantRestConfigProvider: config.TenantRestConfigProvider,
	}

	return r, nil
}

// EnsureCreated ensures that existing StorageClasses use
// `WaitForFirstConsumer` bind mode.
func (r *Resource) EnsureCreated(ctx context.Context, obj interface{}) error {
	cr, err := key.ToCustomResource(obj)
	if err != nil {
		return microerror.Mask(err)
	}

	var tenantClusterK8sClient ctrl.Client
	{
		tenantClusterK8sClient, err = r.getTenantClusterClient(ctx, &cr)
		if tenant.IsAPINotAvailable(err) || tenantcluster.IsTimeout(err) {
			// The kubernetes API is not reachable. This usually happens when a new cluster is being created.
			// This makes the whole controller to fail and stops next handlers from being executed even if they are
			// safe to run. We don't want that to happen so we just return and we'll try again during next loop.
			r.logger.Debugf(ctx, "tenant API not available yet")
			r.logger.Debugf(ctx, "canceling resource")

			return nil
		} else if err != nil {
			return microerror.Mask(err)
		}
	}

	r.logger.Debugf(ctx, "ensuring storageclasses use desired volumeBindingMode")

	defaultSCs, err := defaultStorageClasses()
	if err != nil {
		return microerror.Mask(err)
	}

	for i := range defaultSCs {
		desiredObj := defaultSCs[i]
		if desiredObj.Provisioner == provisionerAzureFile {
			r.logger.Debugf(ctx, "storage class %q uses provisioner %q; skipping as unsupported", desiredObj.Name, desiredObj.Provisioner)
			continue
		}

		r.logger.Debugf(ctx, "finding present storage class object %q", desiredObj.Name)

		var presentObj storagev1.StorageClass
		err := tenantClusterK8sClient.Get(ctx, ctrl.ObjectKey{Name: desiredObj.Name, Namespace: desiredObj.Namespace}, &presentObj)
		if apierrors.IsNotFound(err) {
			// All good. We'll create it.
			r.logger.Debugf(ctx, "did not find present storage class object %q", desiredObj)
		} else if err != nil {
			return microerror.Mask(err)
		} else {
			r.logger.Debugf(ctx, "finding if present storage class object %q has desired volumeBindingMode %q", desiredObj.Name, desiredObj.VolumeBindingMode)
		}

		// If present object matches the desired one, continue to next one.
		if (desiredObj.VolumeBindingMode == nil && presentObj.VolumeBindingMode == nil) || (desiredObj.VolumeBindingMode != nil && presentObj.VolumeBindingMode != nil && *presentObj.VolumeBindingMode == *desiredObj.VolumeBindingMode) {
			r.logger.Debugf(ctx, "present storage class object %q has desired volumeBindingMode: %q", presentObj.Name, desiredObj.VolumeBindingMode)
			continue
		}

		// Volume bind mode is immutable field so we must delete the present
		// object if it exists.
		if !presentObj.CreationTimestamp.IsZero() && presentObj.ResourceVersion != "" {
			r.logger.Debugf(ctx, "present storage class object %q does not have desired volumeBindingMode but %q instead", presentObj.Name, presentObj.VolumeBindingMode)
			r.logger.Debugf(ctx, "deleting present storage class object %q", presentObj.Name)
			err = tenantClusterK8sClient.Delete(ctx, &presentObj)
			if err != nil {
				return microerror.Mask(err)
			}
			r.logger.Debugf(ctx, "deleted present storage class object %q", presentObj.Name)
		}

		r.logger.Debugf(ctx, "creating desired storage class object %q", desiredObj.Name)

		// Finally create the desired object.
		err = tenantClusterK8sClient.Create(ctx, &desiredObj)
		if err != nil {
			return microerror.Mask(err)
		}

		r.logger.Debugf(ctx, "created desired storage class object %q", desiredObj.Name)
	}

	r.logger.Debugf(ctx, "ensured storageclasses use desired volumeBindingMode")

	return nil
}

// EnsureDeleted is no-op.
func (r *Resource) EnsureDeleted(ctx context.Context, obj interface{}) error {
	return nil
}

// Name returns the resource name.
func (r *Resource) Name() string {
	return Name
}

func (r *Resource) getTenantClusterClient(ctx context.Context, azureConfig *providerv1alpha1.AzureConfig) (ctrl.Client, error) {
	var k8sClient k8sclient.Interface
	{
		restConfig, err := r.tenantRestConfigProvider.NewRestConfig(ctx, key.ClusterID(azureConfig), key.ClusterAPIEndpoint(*azureConfig))
		if err != nil {
			return nil, microerror.Mask(err)
		}

		k8sClient, err = k8sclient.NewClients(k8sclient.ClientsConfig{
			Logger:     r.logger,
			RestConfig: rest.CopyConfig(restConfig),
		})
		if err != nil {
			return nil, microerror.Mask(err)
		}
	}

	return k8sClient.CtrlClient(), nil
}

func defaultStorageClasses() ([]storagev1.StorageClass, error) {
	var storageClasses []storagev1.StorageClass

	objs := bytes.Split([]byte(ignition.DefaultStorageClass), []byte("---"))

	for _, bs := range objs {
		sc := storagev1.StorageClass{}
		err := yaml.Unmarshal(bs, &sc)
		if err != nil {
			return nil, microerror.Mask(err)
		}

		if sc.Kind != "StorageClass" {
			continue
		}

		storageClasses = append(storageClasses, sc)
	}

	return storageClasses, nil
}