GCE and AWS provisioners, dynamic provisioning: admins can configure zone(s) where PVs shall be created

examples/persistent-volume-provisioning/README.md

@@ -25,12 +25,13 @@ metadata:
 provisioner: kubernetes.io/aws-ebs
 parameters:
   type: io1
-  zone: us-east-1d
+  zones: us-east-1d, us-east-1c
   iopsPerGB: "10"
 ```
 
 * `type`: `io1`, `gp2`, `sc1`, `st1`. See AWS docs for details. Default: `gp2`.
-* `zone`: AWS zone. If not specified, a random zone from those where Kubernetes cluster has a node is chosen.
+* `zone`: AWS zone. If neither zone nor zones is specified, volumes are generally round-robin-ed across all active zones where Kubernetes cluster has a node. Note: zone and zones parameters must not be used at the same time.
+* `zones`: a comma separated list of AWS zone(s). If neither zone nor zones is specified, volumes are generally round-robin-ed across all active zones where Kubernetes cluster has a node. Note: zone and zones parameters must not be used at the same time.
 * `iopsPerGB`: only for `io1` volumes. I/O operations per second per GiB. AWS volume plugin multiplies this with size of requested volume to compute IOPS of the volume and caps it at 20 000 IOPS (maximum supported by AWS, see AWS docs).
 * `encrypted`: denotes whether the EBS volume should be encrypted or not. Valid values are `true` or `false`.
 * `kmsKeyId`: optional. The full Amazon Resource Name of the key to use when encrypting the volume. If none is supplied but `encrypted` is true, a key is generated by AWS. See AWS docs for valid ARN value.
@@ -45,11 +46,12 @@ metadata:
 provisioner: kubernetes.io/gce-pd
 parameters:
   type: pd-standard
-  zone: us-central1-a
+  zones: us-central1-a, us-central1-b
 ```
 
 * `type`: `pd-standard` or `pd-ssd`. Default: `pd-ssd`
-* `zone`: GCE zone. If not specified, a random zone in the same region as controller-manager will be chosen.
+* `zone`: GCE zone. If neither zone nor zones is specified, volumes are generally round-robin-ed across all active zones where Kubernetes cluster has a node. Note: zone and zones parameters must not be used at the same time.
+* `zones`: a comma separated list of GCE zone(s). If neither zone nor zones is specified, volumes are generally round-robin-ed across all active zones where Kubernetes cluster has a node. Note: zone and zones parameters must not be used at the same time.
 
 #### vSphere
 

pkg/cloudprovider/providers/aws/aws.go

@@ -287,11 +287,14 @@ const (
 
 // VolumeOptions specifies capacity and tags for a volume.
 type VolumeOptions struct {
-	CapacityGB       int
-	Tags             map[string]string
-	PVCName          string
-	VolumeType       string
-	AvailabilityZone string
+	CapacityGB        int
+	Tags              map[string]string
+	PVCName           string
+	VolumeType        string
+	ZonePresent       bool
+	ZonesPresent      bool
+	AvailabilityZone  string
+	AvailabilityZones string
 	// IOPSPerGB x CapacityGB will give total IOPS of the volume to create.
 	// Calculated total IOPS will be capped at MaxTotalIOPS.
 	IOPSPerGB int
@@ -1675,10 +1678,23 @@ func (c *Cloud) CreateDisk(volumeOptions *VolumeOptions) (KubernetesVolumeID, er
 		return "", fmt.Errorf("error querying for all zones: %v", err)
 	}
 
-	createAZ := volumeOptions.AvailabilityZone
-	if createAZ == "" {
+	var createAZ string
+	if !volumeOptions.ZonePresent && !volumeOptions.ZonesPresent {
 		createAZ = volume.ChooseZoneForVolume(allZones, volumeOptions.PVCName)
 	}
+	if !volumeOptions.ZonePresent && volumeOptions.ZonesPresent {
+		if adminSetOfZones, err := volume.ZonesToSet(volumeOptions.AvailabilityZones); err != nil {
+			return "", err
+		} else {
+			createAZ = volume.ChooseZoneForVolume(adminSetOfZones, volumeOptions.PVCName)
+		}
+	}
+	if volumeOptions.ZonePresent && !volumeOptions.ZonesPresent {
+		if err := volume.ValidateZone(volumeOptions.AvailabilityZone); err != nil {
+			return "", err
+		}
+		createAZ = volumeOptions.AvailabilityZone
+	}
 
 	var createType string
 	var iops int64

pkg/volume/aws_ebs/aws_util.go

@@ -91,12 +91,18 @@ func (util *AWSDiskUtil) CreateVolume(c *awsElasticBlockStoreProvisioner) (aws.K
 	}
 	// Apply Parameters (case-insensitive). We leave validation of
 	// the values to the cloud provider.
+	volumeOptions.ZonePresent = false
+	volumeOptions.ZonesPresent = false
 	for k, v := range c.options.Parameters {
 		switch strings.ToLower(k) {
 		case "type":
 			volumeOptions.VolumeType = v
 		case "zone":
+			volumeOptions.ZonePresent = true
 			volumeOptions.AvailabilityZone = v
+		case "zones":
+			volumeOptions.ZonesPresent = true
+			volumeOptions.AvailabilityZones = v
 		case "iopspergb":
 			volumeOptions.IOPSPerGB, err = strconv.Atoi(v)
 			if err != nil {
@@ -114,6 +120,10 @@ func (util *AWSDiskUtil) CreateVolume(c *awsElasticBlockStoreProvisioner) (aws.K
 		}
 	}
 
+	if volumeOptions.ZonePresent && volumeOptions.ZonesPresent {
+		return "", 0, nil, fmt.Errorf("both zone and zones StorageClass parameters must not be used at the same time")
+	}
+
 	// TODO: implement PVC.Selector parsing
 	if c.options.PVC.Spec.Selector != nil {
 		return "", 0, nil, fmt.Errorf("claim.Spec.Selector is not supported for dynamic provisioning on AWS")

pkg/volume/gce_pd/gce_util.go

@@ -86,33 +86,55 @@ func (gceutil *GCEDiskUtil) CreateVolume(c *gcePersistentDiskProvisioner) (strin
 	// Apply Parameters (case-insensitive). We leave validation of
 	// the values to the cloud provider.
 	diskType := ""
-	zone := ""
+	configuredZone := ""
+	configuredZones := ""
+	zonePresent := false
+	zonesPresent := false
 	for k, v := range c.options.Parameters {
 		switch strings.ToLower(k) {
 		case "type":
 			diskType = v
 		case "zone":
-			zone = v
+			zonePresent = true
+			configuredZone = v
+		case "zones":
+			zonesPresent = true
+			configuredZones = v
 		default:
 			return "", 0, nil, fmt.Errorf("invalid option %q for volume plugin %s", k, c.plugin.GetPluginName())
 		}
 	}
 
+	if zonePresent && zonesPresent {
+		return "", 0, nil, fmt.Errorf("both zone and zones StorageClass parameters must not be used at the same time")
+	}
+
 	// TODO: implement PVC.Selector parsing
 	if c.options.PVC.Spec.Selector != nil {
 		return "", 0, nil, fmt.Errorf("claim.Spec.Selector is not supported for dynamic provisioning on GCE")
 	}
 
-	if zone == "" {
-		// No zone specified, choose one randomly in the same region as the
-		// node is running.
-		zones, err := cloud.GetAllZones()
+	var zones sets.String
+	if !zonePresent && !zonesPresent {
+		zones, err = cloud.GetAllZones()
 		if err != nil {
 			glog.V(2).Infof("error getting zone information from GCE: %v", err)
 			return "", 0, nil, err
 		}
-		zone = volume.ChooseZoneForVolume(zones, c.options.PVC.Name)
 	}
+	if !zonePresent && zonesPresent {
+		if zones, err = volume.ZonesToSet(configuredZones); err != nil {
+			return "", 0, nil, err
+		}
+	}
+	if zonePresent && !zonesPresent {
+		if err := volume.ValidateZone(configuredZone); err != nil {
+			return "", 0, nil, err
+		}
+		zones = make(sets.String)
+		zones.Insert(configuredZone)
+	}
+	zone := volume.ChooseZoneForVolume(zones, c.options.PVC.Name)
 
 	err = cloud.CreateDisk(name, diskType, zone, int64(requestGB), *c.options.CloudTags)
 	if err != nil {

pkg/volume/util.go

@@ -410,3 +410,27 @@ func JoinMountOptions(userOptions []string, systemOptions []string) []string {
 	}
 	return allMountOptions.UnsortedList()
 }
+
+// ZonesToSet converts a string containing a comma separated list of zones to set
+func ZonesToSet(zonesString string) (sets.String, error) {
+	zonesSlice := strings.Split(zonesString, ",")
+	zonesSet := make(sets.String)
+	for _, zone := range zonesSlice {
+		trimmedZone := strings.TrimSpace(zone)
+		if trimmedZone == "" {
+			return make(sets.String), fmt.Errorf("comma separated list of zones (%q) must not contain an empty zone", zonesString)
+		}
+		zonesSet.Insert(trimmedZone)
+	}
+	return zonesSet, nil
+}
+
+// ValidateZone returns:
+// - an error in case zone is an empty string or contains only any combination of spaces and tab characters
+// - nil otherwise
+func ValidateZone(zone string) error {
+	if strings.TrimSpace(zone) == "" {
+		return fmt.Errorf("the provided %q zone is not valid, it's an empty string or contains only spaces and tab characters", zone)
+	}
+	return nil
+}

pkg/volume/util_test.go

@@ -523,3 +523,57 @@ func TestChooseZoneForVolume(t *testing.T) {
 		}
 	}
 }
+
+func TestZonesToSet(t *testing.T) {
+	functionUnderTest := "ZonesToSet"
+	// First part: want an error
+	sliceOfZones := []string{"", ",", "us-east-1a, , us-east-1d", ", us-west-1b", "us-west-2b,"}
+	for _, zones := range sliceOfZones {
+		if got, err := ZonesToSet(zones); err == nil {
+			t.Errorf("%v(%v) returned (%v), want (%v)", functionUnderTest, zones, got, "an error")
+		}
+	}
+
+	// Second part: want no error
+	tests := []struct {
+		zones string
+		want  sets.String
+	}{
+		{
+			zones: "us-east-1a",
+			want:  sets.String{"us-east-1a": sets.Empty{}},
+		},
+		{
+			zones: "us-east-1a, us-west-2a",
+			want: sets.String{
+				"us-east-1a": sets.Empty{},
+				"us-west-2a": sets.Empty{},
+			},
+		},
+	}
+	for _, tt := range tests {
+		if got, err := ZonesToSet(tt.zones); err != nil || !got.Equal(tt.want) {
+			t.Errorf("%v(%v) returned (%v), want (%v)", functionUnderTest, tt.zones, got, tt.want)
+		}
+	}
+}
+
+func TestValidateZone(t *testing.T) {
+	functionUnderTest := "ValidateZone"
+
+	// First part: want an error
+	errCases := []string{"", " 	 	 "}
+	for _, errCase := range errCases {
+		if got := ValidateZone(errCase); got == nil {
+			t.Errorf("%v(%v) returned (%v), want (%v)", functionUnderTest, errCase, got, "an error")
+		}
+	}
+
+	// Second part: want no error
+	succCases := []string{" us-east-1a	"}
+	for _, succCase := range succCases {
+		if got := ValidateZone(succCase); got != nil {
+			t.Errorf("%v(%v) returned (%v), want (%v)", functionUnderTest, succCase, got, nil)
+		}
+	}
+}