gd2 plugin: added a plugin for block volume management

Gopkg.toml

@@ -48,7 +48,7 @@
 
 [[constraint]]
   name = "github.com/sirupsen/logrus"
-  version = "~1.0.3"
+  version = "~1.2.0"
 
 [[constraint]]
   name = "github.com/cockroachdb/cmux"

glusterd2.toml.example

@@ -3,3 +3,15 @@ peeraddress = ":24008"
 clientaddress = ":24007"
 #restauth enables/disables REST authentication in glusterd2
 #restauth = true
+
+#[block-hosting-vol-options]
+block-hosting-volume-size = 5368709120 #5GiB
+auto-create-block-hosting-volumes = true
+block-hosting-volume-replica-count = 3
+#block-hosting-volume-type = "Replicate"
+
+#[gluster-block-client-config]
+gluster-block-hostaddr = "192.168.122.16:8081"
+#gluster-block-cacert = "/path/to/ca.crt"
+#gluster-block-user = "username_for_rest_authentication"
+#gluster-block-secret = "secret_for_rest_authentication"

glusterd2/commands/volumes/volume-create.go

@@ -1,6 +1,7 @@
 package volumecommands
 
 import (
+	"context"
 	"errors"
 	"net/http"
 	"path/filepath"
@@ -102,9 +103,6 @@ func registerVolCreateStepFuncs() {
 func volumeCreateHandler(w http.ResponseWriter, r *http.Request) {
 
 	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "/volumeCreateHandler")
-	defer span.End()
-
 	logger := gdctx.GetReqLogger(ctx)
 	var err error
 
@@ -114,45 +112,68 @@ func volumeCreateHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if err := validateVolCreateReq(&req); err != nil {
-		restutils.SendHTTPError(ctx, w, http.StatusBadRequest, err)
+	if status, err := CreateVolume(ctx, req); err != nil {
+		restutils.SendHTTPError(ctx, w, status, err)
 		return
 	}
 
-	if containsReservedGroupProfile(req.Options) {
-		restutils.SendHTTPError(ctx, w, http.StatusBadRequest, gderrors.ErrReservedGroupProfile)
+	volinfo, err := volume.GetVolume(req.Name)
+	if err != nil {
+		// FIXME: If volume was created successfully in the txn above and
+		// then the store goes down by the time we reach here, what do
+		// we return to the client ?
+		restutils.SendHTTPError(ctx, w, http.StatusInternalServerError, err)
 		return
 	}
 
+	logger.WithField("volume-name", volinfo.Name).Info("new volume created")
+	events.Broadcast(volume.NewEvent(volume.EventVolumeCreated, volinfo))
+
+	resp := createVolumeCreateResp(volinfo)
+	restutils.SetLocationHeader(r, w, volinfo.Name)
+	restutils.SendHTTPResponse(ctx, w, http.StatusCreated, resp)
+}
+
+func createVolumeCreateResp(v *volume.Volinfo) *api.VolumeCreateResp {
+	return (*api.VolumeCreateResp)(volume.CreateVolumeInfoResp(v))
+}
+
+// CreateVolume creates a volume
+func CreateVolume(ctx context.Context, req api.VolCreateReq) (status int, err error) {
+	ctx, span := trace.StartSpan(ctx, "/volumeCreateHandler")
+	defer span.End()
+
+	if err := validateVolCreateReq(&req); err != nil {
+		return http.StatusBadRequest, err
+	}
+
+	if containsReservedGroupProfile(req.Options) {
+		return http.StatusBadRequest, gderrors.ErrReservedGroupProfile
+	}
+
 	if req.Size > 0 {
 		applyDefaults(&req)
 
 		if req.SnapshotReserveFactor < 1 {
-			restutils.SendHTTPError(ctx, w, http.StatusBadRequest,
-				errors.New("invalid snapshot reserve factor"))
-			return
+			return http.StatusBadRequest, errors.New("invalid snapshot reserve factor")
 		}
 
 		if err := bricksplanner.PlanBricks(&req); err != nil {
-			restutils.SendHTTPError(ctx, w, http.StatusInternalServerError, err)
-			return
+			return http.StatusInternalServerError, err
 		}
 	} else {
 		if err := checkDupBrickEntryVolCreate(req); err != nil {
-			restutils.SendHTTPError(ctx, w, http.StatusBadRequest, err)
-			return
+			return http.StatusBadRequest, err
 		}
 	}
 
 	req.Options, err = expandGroupOptions(req.Options)
 	if err != nil {
-		restutils.SendHTTPError(ctx, w, http.StatusInternalServerError, err)
-		return
+		return http.StatusInternalServerError, err
 	}
 
 	if err := validateOptions(req.Options, req.VolOptionFlags); err != nil {
-		restutils.SendHTTPError(ctx, w, http.StatusBadRequest, err)
-		return
+		return http.StatusBadRequest, err
 	}
 
 	// Include default Volume Options profile
@@ -171,21 +192,17 @@ func volumeCreateHandler(w http.ResponseWriter, r *http.Request) {
 
 	nodes, err := req.Nodes()
 	if err != nil {
-		restutils.SendHTTPError(ctx, w, http.StatusBadRequest, err)
-		return
+		return http.StatusBadRequest, err
 	}
 
 	txn, err := transactionv2.NewTxnWithLocks(ctx, req.Name)
 	if err != nil {
-		status, err := restutils.ErrToStatusCode(err)
-		restutils.SendHTTPError(ctx, w, status, err)
-		return
+		return restutils.ErrToStatusCode(err)
 	}
 	defer txn.Done()
 
 	if volume.Exists(req.Name) {
-		restutils.SendHTTPError(ctx, w, http.StatusBadRequest, gderrors.ErrVolExists)
-		return
+		return http.StatusBadRequest, gderrors.ErrVolExists
 	}
 
 	txn.Steps = []*transaction.Step{
@@ -219,8 +236,7 @@ func volumeCreateHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if err := txn.Ctx.Set("req", &req); err != nil {
-		restutils.SendHTTPError(ctx, w, http.StatusInternalServerError, err)
-		return
+		return http.StatusInternalServerError, err
 	}
 
 	// Add attributes to the span with info that can be viewed along with traces.
@@ -231,28 +247,8 @@ func volumeCreateHandler(w http.ResponseWriter, r *http.Request) {
 	)
 
 	if err := txn.Do(); err != nil {
-		status, err := restutils.ErrToStatusCode(err)
-		restutils.SendHTTPError(ctx, w, status, err)
-		return
+		return restutils.ErrToStatusCode(err)
 	}
 
-	volinfo, err := volume.GetVolume(req.Name)
-	if err != nil {
-		// FIXME: If volume was created successfully in the txn above and
-		// then the store goes down by the time we reach here, what do
-		// we return to the client ?
-		restutils.SendHTTPError(ctx, w, http.StatusInternalServerError, err)
-		return
-	}
-
-	logger.WithField("volume-name", volinfo.Name).Info("new volume created")
-	events.Broadcast(volume.NewEvent(volume.EventVolumeCreated, volinfo))
-
-	resp := createVolumeCreateResp(volinfo)
-	restutils.SetLocationHeader(r, w, volinfo.Name)
-	restutils.SendHTTPResponse(ctx, w, http.StatusCreated, resp)
-}
-
-func createVolumeCreateResp(v *volume.Volinfo) *api.VolumeCreateResp {
-	return (*api.VolumeCreateResp)(volume.CreateVolumeInfoResp(v))
+	return http.StatusCreated, nil
 }

glusterd2/commands/volumes/volume-start.go

@@ -129,10 +129,6 @@ func registerVolStartStepFuncs() {
 func volumeStartHandler(w http.ResponseWriter, r *http.Request) {
 
 	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "/volumeStartHandler")
-	defer span.End()
-
-	logger := gdctx.GetReqLogger(ctx)
 	volname := mux.Vars(r)["volname"]
 	var req api.VolumeStartReq
 
@@ -142,24 +138,39 @@ func volumeStartHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	txn, err := transactionv2.NewTxnWithLocks(ctx, volname)
+	volinfo, status, err := StartVolume(ctx, volname, req)
 	if err != nil {
-		status, err := restutils.ErrToStatusCode(err)
 		restutils.SendHTTPError(ctx, w, status, err)
 		return
 	}
+
+	events.Broadcast(volume.NewEvent(volume.EventVolumeStarted, volinfo))
+
+	resp := createVolumeStartResp(volinfo)
+	restutils.SendHTTPResponse(ctx, w, http.StatusOK, resp)
+}
+
+// StartVolume starts a volume
+func StartVolume(ctx context.Context, volname string, req api.VolumeStartReq) (volInfo *volume.Volinfo, status int, err error) {
+	logger := gdctx.GetReqLogger(ctx)
+	ctx, span := trace.StartSpan(ctx, "/volumeStartHandler")
+	defer span.End()
+
+	txn, err := transactionv2.NewTxnWithLocks(ctx, volname)
+	if err != nil {
+		status, err := restutils.ErrToStatusCode(err)
+		return nil, status, err
+	}
 	defer txn.Done()
 
 	volinfo, err := volume.GetVolume(volname)
 	if err != nil {
 		status, err := restutils.ErrToStatusCode(err)
-		restutils.SendHTTPError(ctx, w, status, err)
-		return
+		return nil, status, err
 	}
 
 	if volinfo.State == volume.VolStarted && !req.ForceStartBricks {
-		restutils.SendHTTPError(ctx, w, http.StatusBadRequest, errors.ErrVolAlreadyStarted)
-		return
+		return nil, http.StatusBadRequest, errors.ErrVolAlreadyStarted
 	}
 
 	txn.Steps = []*transaction.Step{
@@ -182,15 +193,13 @@ func volumeStartHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if err := txn.Ctx.Set("oldvolinfo", volinfo); err != nil {
-		restutils.SendHTTPError(ctx, w, http.StatusInternalServerError, err)
-		return
+		return nil, http.StatusInternalServerError, err
 	}
 
 	volinfo.State = volume.VolStarted
 
 	if err := txn.Ctx.Set("volinfo", volinfo); err != nil {
-		restutils.SendHTTPError(ctx, w, http.StatusInternalServerError, err)
-		return
+		return nil, http.StatusInternalServerError, err
 	}
 
 	span.AddAttributes(
@@ -201,14 +210,10 @@ func volumeStartHandler(w http.ResponseWriter, r *http.Request) {
 	if err := txn.Do(); err != nil {
 		logger.WithError(err).WithField(
 			"volume", volname).Error("transaction to start volume failed")
-		restutils.SendHTTPError(ctx, w, http.StatusInternalServerError, err)
-		return
+		return nil, http.StatusInternalServerError, err
 	}
 
-	events.Broadcast(volume.NewEvent(volume.EventVolumeStarted, volinfo))
-
-	resp := createVolumeStartResp(volinfo)
-	restutils.SendHTTPResponse(ctx, w, http.StatusOK, resp)
+	return volinfo, http.StatusOK, nil
 }
 
 func createVolumeStartResp(v *volume.Volinfo) *api.VolumeStartResp {

glusterd2/plugin/plugins.go

@@ -4,6 +4,7 @@ package plugin
 
 import (
 	"github.com/gluster/glusterd2/plugins/bitrot"
+	"github.com/gluster/glusterd2/plugins/blockvolume"
 	"github.com/gluster/glusterd2/plugins/device"
 	"github.com/gluster/glusterd2/plugins/events"
 	"github.com/gluster/glusterd2/plugins/georeplication"
@@ -25,4 +26,5 @@ var PluginsList = []GlusterdPlugin{
 	&glustershd.Plugin{},
 	&device.Plugin{},
 	&rebalance.Plugin{},
+	&blockvolume.BlockVolume{},
 }

glusterd2/volume/filters.go

@@ -0,0 +1,51 @@
+package volume
+
+const (
+	// BlockHosted is plugin name for FilterBlockHostedVolumes
+	BlockHosted = "block-hosted"
+)
+
+// Filter will receive a slice of *Volinfo and filters out the undesired one and return slice of desired one only
+type Filter func([]*Volinfo) []*Volinfo
+
+var filters = make(map[string]Filter)
+
+// InstallFilter will register a custom Filter
+func InstallFilter(name string, f Filter) {
+	filters[name] = f
+}
+
+// ApplyFilters applies all registered filters passed in the args to a slice of *Volinfo
+func ApplyFilters(volumes []*Volinfo, names ...string) []*Volinfo {
+	for _, name := range names {
+		if filter, found := filters[name]; found {
+			volumes = filter(volumes)
+		}
+	}
+	return volumes
+}
+
+// ApplyCustomFilters applies all custom filter to a slice of *Volinfo
+func ApplyCustomFilters(volumes []*Volinfo, filters ...Filter) []*Volinfo {
+	for _, filter := range filters {
+		volumes = filter(volumes)
+	}
+
+	return volumes
+}
+
+// FilterBlockHostedVolumes filters out volume which are suitable for hosting block volume
+func FilterBlockHostedVolumes(volumes []*Volinfo) []*Volinfo {
+	var volInfos []*Volinfo
+	for _, volume := range volumes {
+		val, found := volume.Metadata[BlockHosting]
+		if found && val == "yes" {
+			volInfos = append(volInfos, volume)
+		}
+	}
+	return volInfos
+}
+
+func init() {
+	InstallFilter(BlockHosted, FilterBlockHostedVolumes)
+}

glusterd2/volume/metadata.go

@@ -0,0 +1,10 @@
+package volume
+
+const (
+	// BlockHostingAvailableSize is a volume metadata to store available size of hosting volume to create block devices.
+	BlockHostingAvailableSize = "_block-hosting-available-size"
+	// BlockHostingVolumeAutoCreated is volume metadata which will be set as `yes` if gd2 auto create the hosting volume
+	BlockHostingVolumeAutoCreated = "block-hosting-volume-auto-created"
+	// BlockHosting is a volume metadata which will be set as `yes' for volumes which are able to host block devices.
+	BlockHosting = "block-hosting"
+)