Avoid guid pool exhaustion from guid leaks by syncing it with SM (#92)

If the node running pods that use ib network is restarted, those pods'
 GUID are deleted from UFM but are persisted in ib-kubernetes.
They become unusable and might exhaust the GUID pool
if it's configured to be small enough.
The solution is to sync guid pool with UFM because some GUIDs
might have become free to use.

Signed-off-by: amaslennikov <[email protected]>

Signed-off-by: amaslennikov <[email protected]>

Author: almaslennikov

pkg/daemon/daemon.go

@@ -95,11 +95,6 @@ func NewDaemon() (Daemon, error) {
 		return nil, err
 	}
 
-	guidPool, err := guid.NewPool(&daemonConfig.GUIDPool)
-	if err != nil {
-		return nil, err
-	}
-
 	pluginLoader := sm.NewPluginLoader()
 	getSmClientFunc, err := pluginLoader.LoadPlugin(path.Join(
 		daemonConfig.PluginPath, daemonConfig.Plugin+".so"), sm.InitializePluginFunc)
@@ -125,6 +120,14 @@ func NewDaemon() (Daemon, error) {
 		return nil, validateErr
 	}
 
+	guidPool, err := guid.NewPool(&daemonConfig.GUIDPool)
+	if err != nil {
+		return nil, err
+	}
+
+	// Reset guid pool with already allocated guids to avoid collisions
+	err = syncGuidPool(smClient, guidPool)
+
 	podWatcher := watcher.NewWatcher(podEventHandler, client)
 	return &daemon{
 		config:            daemonConfig,
@@ -256,7 +259,16 @@ func (d *daemon) processNetworkGUID(networkID string, spec *utils.IbSriovCniSpec
 	} else {
 		guidAddr, err = d.guidPool.GenerateGUID()
 		if err != nil {
-			return fmt.Errorf("failed to generate GUID for pod ID %s, with error: %v", pi.pod.UID, err)
+			switch err {
+			// If the guid pool is exhausted, need to sync with SM in case there are unsynced changes
+			case guid.GuidPoolExhaustedError:
+				err = syncGuidPool(d.smClient, d.guidPool)
+				if err != nil {
+					return err
+				}
+			default:
+				return fmt.Errorf("failed to generate GUID for pod ID %s, with error: %v", pi.pod.UID, err)
+			}
 		}
 
 		allocatedGUID = guidAddr.String()
@@ -284,6 +296,20 @@ func (d *daemon) processNetworkGUID(networkID string, spec *utils.IbSriovCniSpec
 	return nil
 }
 
+func syncGuidPool(smClient plugins.SubnetManagerClient, guidPool guid.Pool) error {
+	usedGuids, err := smClient.ListGuidsInUse()
+	if err != nil {
+		return err
+	}
+
+	// Reset guid pool with already allocated guids to avoid collisions
+	err = guidPool.Reset(usedGuids)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 // Update and set Pod's network annotation.
 // If failed to update annotation, pod's GUID added into the list to be removed from Pkey.
 func (d *daemon) updatePodNetworkAnnotation(pi *podNetworkInfo, removedList *[]net.HardwareAddr) error {
@@ -537,7 +563,7 @@ func (d *daemon) DeletePeriodicUpdate() {
 	log.Info().Msg("delete periodic update finished")
 }
 
-//  initPool check the guids that are already allocated by the running pods
+// initPool check the guids that are already allocated by the running pods
 func (d *daemon) initPool() error {
 	log.Info().Msg("Initializing GUID pool.")
 

pkg/guid/guid_pool.go

@@ -1,8 +1,8 @@
 package guid
 
 import (
+	"errors"
 	"fmt"
-
 	"github.com/rs/zerolog/log"
 
 	"github.com/Mellanox/ib-kubernetes/pkg/config"
@@ -19,8 +19,13 @@ type Pool interface {
 	// ReleaseGUID release the reservation of the guid.
 	// It returns error if the guid is not in the range.
 	ReleaseGUID(string) error
+
+	// Reset clears the current pool and resets it with given values (may be empty)
+	Reset(guids []string) error
 }
 
+var GuidPoolExhaustedError = errors.New("GUID pool is exhausted")
+
 type guidPool struct {
 	rangeStart  GUID          // first guid in range
 	rangeEnd    GUID          // last guid in range
@@ -50,6 +55,34 @@ func NewPool(conf *config.GUIDPoolConfig) (Pool, error) {
 	}, nil
 }
 
+// Reset clears the current pool and resets it with given values (may be empty)
+func (p *guidPool) Reset(guids []string) error {
+	log.Debug().Msg("resetting guid pool")
+
+	p.guidPoolMap = map[GUID]bool{}
+	if guids == nil {
+		return nil
+	}
+
+	for _, guid := range guids {
+		guidInRange, err := p.isGuidStringInRange(guid)
+		if err != nil {
+			log.Debug().Msgf("error validating GUID: %s: %v", guid, err)
+			return err
+		}
+		if !guidInRange {
+			// Out of range GUID may be expected and shouldn't be allocated in the pool
+			continue
+		}
+		err = p.AllocateGUID(guid)
+		if err != nil {
+			log.Debug().Msgf("error resetting the pool with value: %s: %v", guid, err)
+			return err
+		}
+	}
+	return nil
+}
+
 // GenerateGUID generates a guid from the range
 func (p *guidPool) GenerateGUID() (GUID, error) {
 	// this look will ensure that we check all the range
@@ -62,7 +95,7 @@ func (p *guidPool) GenerateGUID() (GUID, error) {
 	if guid := p.getFreeGUID(p.rangeStart, p.rangeEnd); guid != 0 {
 		return guid, nil
 	}
-	return 0, fmt.Errorf("guid pool range is full")
+	return 0, GuidPoolExhaustedError
 }
 
 // ReleaseGUID release allocated guid
@@ -88,7 +121,7 @@ func (p *guidPool) AllocateGUID(guid string) error {
 		return err
 	}
 
-	if guidAddr < p.rangeStart || guidAddr > p.rangeEnd {
+	if !p.isGuidInRange(guidAddr) {
 		return fmt.Errorf("out of range guid %s, pool range %v - %v", guid, p.rangeStart, p.rangeEnd)
 	}
 
@@ -104,6 +137,18 @@ func isValidRange(rangeStart, rangeEnd GUID) bool {
 	return rangeStart <= rangeEnd && rangeStart != 0 && rangeEnd != 0xFFFFFFFFFFFFFFFF
 }
 
+func (p *guidPool) isGuidInRange(guid GUID) bool {
+	return guid >= p.rangeStart && guid <= p.rangeEnd
+}
+
+func (p *guidPool) isGuidStringInRange(guid string) (bool, error) {
+	guidAddr, err := ParseGUID(guid)
+	if err != nil {
+		return false, err
+	}
+	return p.isGuidInRange(guidAddr), nil
+}
+
 // getFreeGUID return free guid in given range
 func (p *guidPool) getFreeGUID(start, end GUID) GUID {
 	for guid := start; guid <= end; guid++ {

pkg/guid/guid_test.go

@@ -9,6 +9,57 @@ import (
 
 var _ = Describe("GUID Pool", func() {
 	conf := &config.GUIDPoolConfig{RangeStart: "02:00:00:00:00:00:00:00", RangeEnd: "02:FF:FF:FF:FF:FF:FF:FF"}
+	Context("ResetPool", func() {
+		It("Reset pool clears previous values", func() {
+			pool, err := NewPool(conf)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(pool).ToNot(BeNil())
+
+			err = pool.AllocateGUID("02:00:00:00:00:00:00:00")
+			Expect(err).ToNot(HaveOccurred())
+			err = pool.AllocateGUID("02:00:00:00:FF:00:00:00")
+			Expect(err).ToNot(HaveOccurred())
+
+			pool.Reset(nil)
+
+			err = pool.ReleaseGUID("02:00:00:00:00:00:00:00")
+			Expect(err).To(HaveOccurred())
+			err = pool.ReleaseGUID("02:00:00:00:FF:00:00:00")
+			Expect(err).To(HaveOccurred())
+		})
+		It("Reset pool stores new values", func() {
+			pool, err := NewPool(conf)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(pool).ToNot(BeNil())
+
+			expectedGuids := []string{"02:00:00:00:00:00:00:3e", "02:00:0F:F0:00:FF:00:09", "02:00:00:00:00:00:00:00"}
+
+			pool.Reset(expectedGuids)
+
+			for _, expectedGuid := range expectedGuids {
+				err = pool.ReleaseGUID(expectedGuid)
+				Expect(err).ToNot(HaveOccurred())
+			}
+		})
+		It("Exhausted pool throws error and doesn't after reset", func() {
+			conf := &config.GUIDPoolConfig{RangeStart: "02:00:00:00:00:00:00:00", RangeEnd: "02:00:00:00:00:00:00:00"}
+			pool, err := NewPool(conf)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(pool).ToNot(BeNil())
+			guid, err := pool.GenerateGUID()
+			Expect(err).ToNot(HaveOccurred())
+			err = pool.AllocateGUID(guid.String())
+			Expect(err).ToNot(HaveOccurred())
+			guid, err = pool.GenerateGUID()
+			Expect(err).To(Equal(GuidPoolExhaustedError))
+
+			err = pool.Reset(nil)
+			Expect(err).ToNot(HaveOccurred())
+
+			guid, err = pool.GenerateGUID()
+			Expect(err).ToNot(HaveOccurred())
+		})
+	})
 	Context("NewPool", func() {
 		It("Create guid pool with valid  parameters", func() {
 			pool, err := NewPool(conf)

pkg/sm/plugins/noop/noop.go

@@ -48,6 +48,11 @@ func (p *plugin) RemoveGuidsFromPKey(pkey int, guids []net.HardwareAddr) error {
 	return nil
 }
 
+func (p *plugin) ListGuidsInUse() ([]string, error) {
+	log.Info().Msg("noop Plugin ListGuidsInUse()")
+	return nil, nil
+}
+
 // Initialize applies configs to plugin and return a subnet manager client
 func Initialize() (plugins.SubnetManagerClient, error) {
 	log.Info().Msg("Initializing noop plugin")

pkg/sm/plugins/plugin.go

@@ -19,4 +19,7 @@ type SubnetManagerClient interface {
 	// RemoveGuidsFromPKey remove guids for given pkey.
 	// It return error if failed.
 	RemoveGuidsFromPKey(pkey int, guids []net.HardwareAddr) error
+
+	// ListGuidsInUse returns a list of all GUIDS associated with PKeys
+	ListGuidsInUse() ([]string, error)
 }

pkg/sm/plugins/ufm/ufm.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/json"
 	"fmt"
 	"net"
 	"net/http"
@@ -133,6 +134,48 @@ func (u *ufmPlugin) RemoveGuidsFromPKey(pKey int, guids []net.HardwareAddr) erro
 	return nil
 }
 
+// convertToMacAddr adds semicolons each 2 characters to convert to MAC format
+// UFM returns GUIDS without any delimiters, so expected format is as follows:
+// FF00FF00FF00FF00
+func convertToMacAddr(guid string) string {
+	for i := 2; i < len(guid); i += 3 {
+		guid = guid[:i] + ":" + guid[i:]
+	}
+	return guid
+}
+
+type Guid struct {
+	GuidValue string `json:"guid"`
+}
+
+type PKey struct {
+	Guids []Guid `json:"guids"`
+}
+
+// ListGuidsInUse returns all guids currently in use by pKeys
+func (u *ufmPlugin) ListGuidsInUse() ([]string, error) {
+	response, err := u.client.Get(u.buildURL("/ufmRest/resources/pkeys/?guids_data=true"), http.StatusOK)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get the list of guids: %v", err)
+	}
+
+	var pKeys map[string]PKey
+
+	if err := json.Unmarshal(response, &pKeys); err != nil {
+		return nil, fmt.Errorf("failed to get the list of guids: %v", err)
+	}
+
+	var guids []string
+
+	for pkey, _ := range pKeys {
+		pkeyData := pKeys[pkey]
+		for _, guidData := range pkeyData.Guids {
+			guids = append(guids, convertToMacAddr(guidData.GuidValue))
+		}
+	}
+	return guids, nil
+}
+
 func (u *ufmPlugin) buildURL(path string) string {
 	return fmt.Sprintf("%s://%s:%d%s", u.conf.HTTPSchema, u.conf.Address, u.conf.Port, path)
 }

pkg/sm/plugins/ufm/ufm_test.go

@@ -152,4 +152,43 @@ var _ = Describe("Ufm Subnet Manager Client plugin", func() {
 			Expect(&errMsg).To(Equal(&errMessage))
 		})
 	})
+	Context("ListGuidsInUse", func() {
+		It("Remove guid from valid pkey", func() {
+			testResponse := `{
+				"0x7fff": {
+					"guids": []
+				},
+				"0x7aff": {
+					"test": "val"
+				},
+				"0x5": {
+					"guids": [
+						{
+							"guid": "020000000000003e"
+						},
+						{
+							"guid": "02000FF000FF0009"
+						}
+					]
+				},
+				"0x6": {
+					"guids": [
+						{
+							"guid": "0200000000000000"
+						}
+					]
+				}
+			}`
+
+			client := &mocks.Client{}
+			client.On("Get", mock.Anything, mock.Anything).Return([]byte(testResponse), nil)
+
+			plugin := &ufmPlugin{client: client, conf: UFMConfig{}}
+			guids, err := plugin.ListGuidsInUse()
+			Expect(err).ToNot(HaveOccurred())
+
+			expectedGuids := []string{"02:00:00:00:00:00:00:3e", "02:00:0F:F0:00:FF:00:09", "02:00:00:00:00:00:00:00"}
+			Expect(guids).To(ConsistOf(expectedGuids))
+		})
+	})
 })