Add logic for openebs namespace determination from cli code (#21)

Signed-off-by: Abhinandan-Purkait <abhinandan.purkait@mayadata.io>

client/k8s.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 
 	cstorv1 "github.com/openebs/api/v2/pkg/apis/cstor/v1"
 	"github.com/openebs/api/v2/pkg/apis/openebs.io/v1alpha1"
@@ -47,9 +48,9 @@ type K8sAPIVersion string
 // K8sClient provides the necessary utility to operate over
 // various K8s Kind objects
 type K8sClient struct {
-	// ns refers to K8s namespace where the operation
+	// Ns refers to K8s namespace where the operation
 	// will be performed
-	ns string
+	Ns string
 	// K8sCS refers to the Clientset capable of communicating
 	// with the K8s cluster
 	K8sCS kubernetes.Interface
@@ -59,7 +60,7 @@ type K8sClient struct {
 }
 
 // NewK8sClient creates a new K8sClient
-// TODO: improve K8sClientset instantiation. for example remove the ns from
+// TODO: improve K8sClientset instantiation. for example remove the Ns from
 // K8sClient struct
 func NewK8sClient(ns string) (*K8sClient, error) {
 	// get the appropriate clientsets & set the kubeconfig accordingly
@@ -75,7 +76,7 @@ func NewK8sClient(ns string) (*K8sClient, error) {
 		return nil, errors.Wrap(err, "failed to build OpenEBS clientset")
 	}
 	return &K8sClient{
-		ns:        ns,
+		Ns:        ns,
 		K8sCS:     k8sCS,
 		OpenebsCS: openebsCS,
 	}, nil
@@ -130,6 +131,14 @@ func homeDir() string {
 	}
 	return os.Getenv("KUBECONFIG")
 }
+// GetOpenEBSNamespace from the specific engine component based on cas-type
+func (k K8sClient) GetOpenEBSNamespace(casType string) (string, error) {
+	pods, err := k.K8sCS.CoreV1().Pods("").List(context.TODO(), metav1.ListOptions{LabelSelector: fmt.Sprintf("openebs.io/component-name=%s", util.CasTypeAndComponentNameMap[strings.ToLower(casType)])})
+	if err != nil || len(pods.Items) == 0 {
+		return "", errors.New("unable to determine openebs namespace")
+	}
+	return pods.Items[0].Namespace, nil
+}
 
 // GetStorageClass using the K8sClient's storage class client
 func (k K8sClient) GetStorageClass(driver string) (*v1.StorageClass, error) {
@@ -160,7 +169,7 @@ func (k K8sClient) GetcStorVolumes() (*cstorv1.CStorVolumeList, error) {
 
 // GetcStorVolume fetches the volume object of the given name in the given namespace
 func (k K8sClient) GetcStorVolume(volName string) (*cstorv1.CStorVolume, error) {
-	volInfo, err := k.OpenebsCS.CstorV1().CStorVolumes(k.ns).Get(context.TODO(), volName, metav1.GetOptions{})
+	volInfo, err := k.OpenebsCS.CstorV1().CStorVolumes(k.Ns).Get(context.TODO(), volName, metav1.GetOptions{})
 	if err != nil {
 		return nil, errors.Wrapf(err, "error while while getting volume %s", volName)
 	}
@@ -210,9 +219,9 @@ func (k K8sClient) GetPV(name string) (*corev1.PersistentVolume, error) {
 
 // GetCVC used to get cStor Volume Config information for cStor a given volume using a cStorClient
 func (k K8sClient) GetCVC(name string) (*cstorv1.CStorVolumeConfig, error) {
-	cStorVolumeConfig, err := k.OpenebsCS.CstorV1().CStorVolumeConfigs(k.ns).Get(context.TODO(), name, metav1.GetOptions{})
+	cStorVolumeConfig, err := k.OpenebsCS.CstorV1().CStorVolumeConfigs(k.Ns).Get(context.TODO(), name, metav1.GetOptions{})
 	if err != nil {
-		return nil, errors.Wrapf(err, "error while getting cStor Volume Config for  %s in %s", name, k.ns)
+		return nil, errors.Wrapf(err, "error while getting cStor Volume Config for  %s in %s", name, k.Ns)
 	}
 	return cStorVolumeConfig, nil
 }
@@ -283,7 +292,7 @@ func (k K8sClient) GetCVA(volumeName string) (*cstorv1.CStorVolumeAttachment, er
 
 // GetCstorVolumeTargetPod for the passed volume to show details
 func (k K8sClient) GetCstorVolumeTargetPod(volumeClaim string, volumeName string) (*corev1.Pod, error) {
-	pods, err := k.K8sCS.CoreV1().Pods(k.ns).List(context.TODO(), metav1.ListOptions{LabelSelector: fmt.Sprintf("openebs.io/persistent-volume-claim=%s,openebs.io/persistent-volume=%s,openebs.io/target=cstor-target", volumeClaim, volumeName)})
+	pods, err := k.K8sCS.CoreV1().Pods(k.Ns).List(context.TODO(), metav1.ListOptions{LabelSelector: fmt.Sprintf("openebs.io/persistent-volume-claim=%s,openebs.io/persistent-volume=%s,openebs.io/target=cstor-target", volumeClaim, volumeName)})
 	if err != nil || len(pods.Items) == 0 {
 		return nil, errors.New("The target pod for the volume was not found")
 	}
@@ -292,7 +301,7 @@ func (k K8sClient) GetCstorVolumeTargetPod(volumeClaim string, volumeName string
 
 // GetcStorPool using the OpenEBS's Client
 func (k K8sClient) GetcStorPool(poolName string) (*cstorv1.CStorPoolInstance, error) {
-	cStorPool, err := k.OpenebsCS.CstorV1().CStorPoolInstances(k.ns).Get(context.TODO(), poolName, metav1.GetOptions{})
+	cStorPool, err := k.OpenebsCS.CstorV1().CStorPoolInstances(k.Ns).Get(context.TODO(), poolName, metav1.GetOptions{})
 	if err != nil {
 		return nil, errors.Wrapf(err, "Error while while getting cspi")
 	}
@@ -301,7 +310,7 @@ func (k K8sClient) GetcStorPool(poolName string) (*cstorv1.CStorPoolInstance, er
 
 // GetBlockDevice using the OpenEBS's Client
 func (k K8sClient) GetBlockDevice(bd string) (*v1alpha1.BlockDevice, error) {
-	blockDevice, err := k.OpenebsCS.OpenebsV1alpha1().BlockDevices(k.ns).Get(context.TODO(), bd, metav1.GetOptions{})
+	blockDevice, err := k.OpenebsCS.OpenebsV1alpha1().BlockDevices(k.Ns).Get(context.TODO(), bd, metav1.GetOptions{})
 	if err != nil {
 		return nil, errors.Wrapf(err, "Error while while getting block device")
 	}
@@ -311,7 +320,7 @@ func (k K8sClient) GetBlockDevice(bd string) (*v1alpha1.BlockDevice, error) {
 // GetCVRByPoolName using the OpenEBS's Client
 func (k K8sClient) GetCVRByPoolName(poolName string) (*cstorv1.CStorVolumeReplicaList, error) {
 	label := "cstorpoolinstance.openebs.io/name" + "=" + poolName
-	CVRs, err := k.OpenebsCS.CstorV1().CStorVolumeReplicas(k.ns).List(context.TODO(), metav1.ListOptions{LabelSelector: label})
+	CVRs, err := k.OpenebsCS.CstorV1().CStorVolumeReplicas(k.Ns).List(context.TODO(), metav1.ListOptions{LabelSelector: label})
 	if err != nil {
 		return nil, errors.Wrapf(err, "error while getting cStor Volume Replica for pool %s", poolName)
 	}

kubectl-openebs/cli/command/describe/pvc_info.go

@@ -80,33 +80,36 @@ PV Status	 : {{.PVStatus}}
 
 // NewCmdDescribePVC Displays the pvc describe details
 func NewCmdDescribePVC() *cobra.Command {
+	var openebsNs string
 	cmd := &cobra.Command{
 		Use:     "pvc",
 		Aliases: []string{"pvcs", "persistentvolumeclaims", "persistentvolumeclaim"},
 		Short:   "Displays PersistentVolumeClaim information",
 		Long:    pvcInfoCommandHelpText,
 		Example: `kubectl openebs describe pvc cstor-vol-1 cstor-vol-2 -n storage`,
 		Run: func(cmd *cobra.Command, args []string) {
-			var pvNs string // This namespace belongs to the PVC entered
+			var pvNs, openebsNamespace string
 			if pvNs, _ = cmd.Flags().GetString("namespace"); pvNs == "" {
 				pvNs = "default"
 			}
-			util.CheckErr(RunPVCInfo(cmd, args, pvNs), util.Fatal)
+			openebsNamespace, _ = cmd.Flags().GetString("openebs-namespace")
+			util.CheckErr(RunPVCInfo(cmd, args, pvNs, openebsNamespace), util.Fatal)
 		},
 	}
+	cmd.Flags().StringVarP(&openebsNs, "openebs-namespace", "", "", "to read the openebs namespace from user.\nIf not provided it is determined from components.")
 	return cmd
 }
 
 // RunPVCInfo runs info command and make call to display the results
-func RunPVCInfo(cmd *cobra.Command, pvcs []string, ns string) error {
+func RunPVCInfo(cmd *cobra.Command, pvcs []string, ns string, openebsNs string) error {
 	if len(pvcs) == 0 {
 		return errors.New("Please give at least one pvc name to describe")
 	}
 	// TODO: Make K8sClient to be able to determine openebs namespace by itself.
 	// Below is currently hardcoded to support only if resources are in openebs ns
 	// because the -n flag is used to take the pvc namespace and same cannot be used to
 	// take the openebs namespace
-	clientset, err := client.NewK8sClient("openebs")
+	clientset, err := client.NewK8sClient(openebsNs)
 	if err != nil {
 		return errors.Wrap(err, "Failed to execute describe pvc command")
 	}
@@ -130,7 +133,13 @@ func RunPVCInfo(cmd *cobra.Command, pvcs []string, ns string) error {
 			// Get the casType from the storage class and branch on basic of CSTOR and NON-CSTOR PVCs.
 			casType := util.GetCasTypeFromSC(sc)
 			if casType == util.CstorCasType {
-
+				if openebsNs == "" {
+					nsFromCli, err := clientset.GetOpenEBSNamespace(util.CstorCasType)
+					if err != nil {
+						return errors.Wrap(err, "Error determining the openebs namespace, please specify using \"--openebs-namespace\" flag")
+					}
+					clientset.Ns = nsFromCli
+				}
 				// Create Empty template objects and fill gradually when underlying sub CRs are identified.
 				pvcInfo := util.CstorPVCInfo{}
 				cvcInfo := util.CVCInfo{}

kubectl-openebs/cli/util/constant.go

@@ -44,3 +44,18 @@ const (
 	// StorageKey key present in pvc status.capacity
 	StorageKey = "storage"
 )
+
+var (
+	// CasTypeAndComponentNameMap stores the component name of the corresponding cas type
+	CasTypeAndComponentNameMap = map[string]string{
+		"cstor": "openebs-cstor-csi-controller",
+	}
+	// ProvsionerAndCasTypeMap stores the cas type name of the corresponding provisioner
+	ProvsionerAndCasTypeMap = map[string]string{
+		"cstor.csi.openebs.io":         "cstor",
+		"openebs.io/provisioner-iscsi": "jiva",
+		"openebs.io/local":             "local",
+		"local.csi.openebs.io ":        "localpv-lvm",
+		"zfs.csi.openebs.io":           "localpv-zfs",
+	}
+)

kubectl-openebs/cli/util/k8s_utils.go

@@ -17,10 +17,11 @@ limitations under the License.
 package util
 
 import (
+	"strconv"
+
 	cstorv1 "github.com/openebs/api/v2/pkg/apis/cstor/v1"
 	corev1 "k8s.io/api/core/v1"
 	v1 "k8s.io/api/storage/v1"
-	"strconv"
 )
 
 // GetUsedCapacityFromCVR as the healthy replicas would have the correct used capacity details
@@ -70,6 +71,9 @@ func GetCasTypeFromSC(v1SC *v1.StorageClass) string {
 			return v1SC.Parameters[OpenEBSCasTypeKeySc]
 		}
 	}
+	if v, ok := ProvsionerAndCasTypeMap[v1SC.Provisioner]; ok {
+		return v
+	}
 	return Unknown
 }