pkg/probe/probe.go - voltha-lib-go - Gitiles

 /*
  * 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/v3/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
 }
	/*
	* 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/v3/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
	}