diff --git a/vendor/github.com/opencord/voltha-lib-go/v4/pkg/probe/probe.go b/vendor/github.com/opencord/voltha-lib-go/v4/pkg/probe/probe.go
new file mode 100644
index 0000000..f13f257
--- /dev/null
+++ b/vendor/github.com/opencord/voltha-lib-go/v4/pkg/probe/probe.go
@@ -0,0 +1,305 @@
+/*
+ * Copyright 2019-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package probe
+
+import (
+	"context"
+	"fmt"
+	"github.com/opencord/voltha-lib-go/v4/pkg/log"
+	"net/http"
+	"sync"
+)
+
+// ProbeContextKey used to fetch the Probe instance from a context
+type ProbeContextKeyType string
+
+// ServiceStatus typed values for service status
+type ServiceStatus int
+
+const (
+	// ServiceStatusUnknown initial state of services
+	ServiceStatusUnknown ServiceStatus = iota
+
+	// ServiceStatusPreparing to optionally be used for prep, such as connecting
+	ServiceStatusPreparing
+
+	// ServiceStatusPrepared to optionally be used when prep is complete, but before run
+	ServiceStatusPrepared
+
+	// ServiceStatusRunning service is functional
+	ServiceStatusRunning
+
+	// ServiceStatusStopped service has stopped, but not because of error
+	ServiceStatusStopped
+
+	// ServiceStatusFailed service has stopped because of an error
+	ServiceStatusFailed
+
+	// ServiceStatusNotReady service has started but is unable to accept requests
+	ServiceStatusNotReady
+)
+
+const (
+	// ProbeContextKey value of context key to fetch probe
+	ProbeContextKey = ProbeContextKeyType("status-update-probe")
+)
+
+// String convert ServiceStatus values to strings
+func (s ServiceStatus) String() string {
+	switch s {
+	default:
+		fallthrough
+	case ServiceStatusUnknown:
+		return "Unknown"
+	case ServiceStatusPreparing:
+		return "Preparing"
+	case ServiceStatusPrepared:
+		return "Prepared"
+	case ServiceStatusRunning:
+		return "Running"
+	case ServiceStatusStopped:
+		return "Stopped"
+	case ServiceStatusFailed:
+		return "Failed"
+	case ServiceStatusNotReady:
+		return "NotReady"
+	}
+}
+
+// ServiceStatusUpdate status update event
+type ServiceStatusUpdate struct {
+	Name   string
+	Status ServiceStatus
+}
+
+// Probe reciever on which to implement probe capabilities
+type Probe struct {
+	readyFunc  func(map[string]ServiceStatus) bool
+	healthFunc func(map[string]ServiceStatus) bool
+
+	mutex     sync.RWMutex
+	status    map[string]ServiceStatus
+	isReady   bool
+	isHealthy bool
+}
+
+// WithReadyFunc override the default ready calculation function
+func (p *Probe) WithReadyFunc(readyFunc func(map[string]ServiceStatus) bool) *Probe {
+	p.readyFunc = readyFunc
+	return p
+}
+
+// WithHealthFunc override the default health calculation function
+func (p *Probe) WithHealthFunc(healthFunc func(map[string]ServiceStatus) bool) *Probe {
+	p.healthFunc = healthFunc
+	return p
+}
+
+// RegisterService register one or more service names with the probe, status will be track against service name
+func (p *Probe) RegisterService(ctx context.Context, names ...string) {
+	p.mutex.Lock()
+	defer p.mutex.Unlock()
+	if p.status == nil {
+		p.status = make(map[string]ServiceStatus)
+	}
+	for _, name := range names {
+		if _, ok := p.status[name]; !ok {
+			p.status[name] = ServiceStatusUnknown
+			logger.Debugw(ctx, "probe-service-registered", log.Fields{"service-name": name})
+		}
+	}
+
+	if p.readyFunc != nil {
+		p.isReady = p.readyFunc(p.status)
+	} else {
+		p.isReady = defaultReadyFunc(p.status)
+	}
+
+	if p.healthFunc != nil {
+		p.isHealthy = p.healthFunc(p.status)
+	} else {
+		p.isHealthy = defaultHealthFunc(p.status)
+	}
+}
+
+// UpdateStatus utility function to send a service update to the probe
+func (p *Probe) UpdateStatus(ctx context.Context, name string, status ServiceStatus) {
+	p.mutex.Lock()
+	defer p.mutex.Unlock()
+	if p.status == nil {
+		p.status = make(map[string]ServiceStatus)
+	}
+
+	// if status hasn't changed, avoid doing useless work
+	existingStatus, ok := p.status[name]
+	if ok && (existingStatus == status) {
+		return
+	}
+
+	p.status[name] = status
+	if p.readyFunc != nil {
+		p.isReady = p.readyFunc(p.status)
+	} else {
+		p.isReady = defaultReadyFunc(p.status)
+	}
+
+	if p.healthFunc != nil {
+		p.isHealthy = p.healthFunc(p.status)
+	} else {
+		p.isHealthy = defaultHealthFunc(p.status)
+	}
+	logger.Debugw(ctx, "probe-service-status-updated",
+		log.Fields{
+			"service-name": name,
+			"status":       status.String(),
+			"ready":        p.isReady,
+			"health":       p.isHealthy,
+		})
+}
+
+func (p *Probe) GetStatus(name string) ServiceStatus {
+	p.mutex.Lock()
+	defer p.mutex.Unlock()
+
+	if p.status == nil {
+		p.status = make(map[string]ServiceStatus)
+	}
+
+	currentStatus, ok := p.status[name]
+	if ok {
+		return currentStatus
+	}
+
+	return ServiceStatusUnknown
+}
+
+func GetProbeFromContext(ctx context.Context) *Probe {
+	if ctx != nil {
+		if value := ctx.Value(ProbeContextKey); value != nil {
+			if p, ok := value.(*Probe); ok {
+				return p
+			}
+		}
+	}
+	return nil
+}
+
+// UpdateStatusFromContext a convenience function to pull the Probe reference from the
+// Context, if it exists, and then calling UpdateStatus on that Probe reference. If Context
+// is nil or if a Probe reference is not associated with the ProbeContextKey then nothing
+// happens
+func UpdateStatusFromContext(ctx context.Context, name string, status ServiceStatus) {
+	p := GetProbeFromContext(ctx)
+	if p != nil {
+		p.UpdateStatus(ctx, name, status)
+	}
+}
+
+// pulled out to a function to help better enable unit testing
+func (p *Probe) readzFunc(w http.ResponseWriter, req *http.Request) {
+	p.mutex.RLock()
+	defer p.mutex.RUnlock()
+	if p.isReady {
+		w.WriteHeader(http.StatusOK)
+	} else {
+		w.WriteHeader(http.StatusTeapot)
+	}
+}
+func (p *Probe) healthzFunc(w http.ResponseWriter, req *http.Request) {
+	p.mutex.RLock()
+	defer p.mutex.RUnlock()
+	if p.isHealthy {
+		w.WriteHeader(http.StatusOK)
+	} else {
+		w.WriteHeader(http.StatusTeapot)
+	}
+}
+func (p *Probe) detailzFunc(w http.ResponseWriter, req *http.Request) {
+	ctx := context.Background()
+	p.mutex.RLock()
+	defer p.mutex.RUnlock()
+	w.Header().Set("Content-Type", "application/json")
+	if _, err := w.Write([]byte("{")); err != nil {
+		logger.Errorw(ctx, "write-response", log.Fields{"error": err})
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	comma := ""
+	for c, s := range p.status {
+		if _, err := w.Write([]byte(fmt.Sprintf("%s\"%s\": \"%s\"", comma, c, s.String()))); err != nil {
+			logger.Errorw(ctx, "write-response", log.Fields{"error": err})
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		comma = ", "
+	}
+	if _, err := w.Write([]byte("}")); err != nil {
+		logger.Errorw(ctx, "write-response", log.Fields{"error": err})
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	w.WriteHeader(http.StatusOK)
+}
+
+// ListenAndServe implements 3 HTTP endpoints on the given port for healthz, readz, and detailz. Returns only on error
+func (p *Probe) ListenAndServe(ctx context.Context, address string) {
+	mux := http.NewServeMux()
+
+	// Returns the result of the readyFunc calculation
+	mux.HandleFunc("/readz", p.readzFunc)
+
+	// Returns the result of the healthFunc calculation
+	mux.HandleFunc("/healthz", p.healthzFunc)
+
+	// Returns the details of the services and their status as JSON
+	mux.HandleFunc("/detailz", p.detailzFunc)
+	s := &http.Server{
+		Addr:    address,
+		Handler: mux,
+	}
+	logger.Fatal(ctx, s.ListenAndServe())
+}
+
+func (p *Probe) IsReady() bool {
+	return p.isReady
+}
+
+// defaultReadyFunc if all services are running then ready, else not
+func defaultReadyFunc(services map[string]ServiceStatus) bool {
+	if len(services) == 0 {
+		return false
+	}
+	for _, status := range services {
+		if status != ServiceStatusRunning {
+			return false
+		}
+	}
+	return true
+}
+
+// defaultHealthFunc if no service is stopped or failed, then healthy, else not.
+// service is start as unknown, so they are considered healthy
+func defaultHealthFunc(services map[string]ServiceStatus) bool {
+	if len(services) == 0 {
+		return false
+	}
+	for _, status := range services {
+		if status == ServiceStatusStopped || status == ServiceStatusFailed {
+			return false
+		}
+	}
+	return true
+}