cmd/openolt-adapter/main.go - voltha-eponolt-adapter - Gitiles

 /*
 * Copyright 2018-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 main invokes the application
 package main

 import (
 	"context"
 	"errors"
 	"fmt"
 	"os"
 	"os/signal"
 	"syscall"
 	"time"

 	"github.com/opencord/voltha-lib-go/v3/pkg/adapters/adapterif"

 	"github.com/opencord/voltha-lib-go/v3/pkg/adapters"
 	com "github.com/opencord/voltha-lib-go/v3/pkg/adapters/common"
 	conf "github.com/opencord/voltha-lib-go/v3/pkg/config"
 	"github.com/opencord/voltha-lib-go/v3/pkg/db/kvstore"
 	"github.com/opencord/voltha-lib-go/v3/pkg/kafka"
 	"github.com/opencord/voltha-lib-go/v3/pkg/log"
 	"github.com/opencord/voltha-lib-go/v3/pkg/probe"
 	"github.com/opencord/voltha-lib-go/v3/pkg/version"
 	"github.com/opencord/voltha-openolt-adapter/internal/pkg/config"
 	ac "github.com/opencord/voltha-openolt-adapter/internal/pkg/core"
 	ic "github.com/opencord/voltha-protos/v3/go/inter_container"
 	"github.com/opencord/voltha-protos/v3/go/voltha"
 )

 type adapter struct {
 	instanceID       string
 	config           *config.AdapterFlags
 	iAdapter         adapters.IAdapter
 	kafkaClient      kafka.Client
 	kvClient         kvstore.Client
 	kip              kafka.InterContainerProxy
 	coreProxy        adapterif.CoreProxy
 	adapterProxy     adapterif.AdapterProxy
 	eventProxy       adapterif.EventProxy
 	halted           bool
 	exitChannel      chan int
 	receiverChannels []<-chan *ic.InterContainerMessage
 }

 func newAdapter(cf *config.AdapterFlags) *adapter {
 	var a adapter
 	a.instanceID = cf.InstanceID
 	a.config = cf
 	a.halted = false
 	a.exitChannel = make(chan int, 1)
 	a.receiverChannels = make([]<-chan *ic.InterContainerMessage, 0)
 	return &a
 }

 func (a *adapter) start(ctx context.Context) {
 	logger.Info(ctx, "Starting Core Adapter components")
 	var err error

 	var p *probe.Probe
 	if value := ctx.Value(probe.ProbeContextKey); value != nil {
 		if _, ok := value.(*probe.Probe); ok {
 			p = value.(*probe.Probe)
 			p.RegisterService(
 				ctx,
 				"message-bus",
 				"kv-store",
 				"container-proxy",
 				"core-request-handler",
 				"register-with-core",
 			)
 		}
 	}

 	// Setup KV Client
 	logger.Debugw(ctx, "create-kv-client", log.Fields{"kvstore": a.config.KVStoreType})
 	if err = a.setKVClient(ctx); err != nil {
 		logger.Fatalw(ctx, "error-setting-kv-client", log.Fields{"error": err})
 	}

 	if p != nil {
 		p.UpdateStatus(ctx, "kv-store", probe.ServiceStatusRunning)
 	}

 	// Setup Log Config
 	cm := conf.NewConfigManager(ctx, a.kvClient, a.config.KVStoreType, a.config.KVStoreAddress, a.config.KVStoreTimeout)
 	go conf.StartLogLevelConfigProcessing(cm, ctx)
 	go conf.StartLogFeaturesConfigProcessing(cm, ctx)

 	// Setup Kafka Client
 	if a.kafkaClient, err = newKafkaClient(ctx, "sarama", a.config.KafkaAdapterAddress); err != nil {
 		logger.Fatalw(ctx, "Unsupported-common-client", log.Fields{"error": err})
 	}

 	if p != nil {
 		p.UpdateStatus(ctx, "message-bus", probe.ServiceStatusRunning)
 	}

 	// setup endpointManager

 	// Start the common InterContainer Proxy - retries indefinitely
 	if a.kip, err = a.startInterContainerProxy(ctx, -1); err != nil {
 		logger.Fatal(ctx, "error-starting-inter-container-proxy")
 	}

 	// Create the core proxy to handle requests to the Core
 	a.coreProxy = com.NewCoreProxy(ctx, a.kip, a.config.Topic, a.config.CoreTopic)

 	// Create the adaptor proxy to handle request between olt and onu
 	a.adapterProxy = com.NewAdapterProxy(ctx, a.kip, a.config.CoreTopic, cm.Backend)

 	// Create the event proxy to post events to KAFKA
 	a.eventProxy = com.NewEventProxy(com.MsgClient(a.kafkaClient), com.MsgTopic(kafka.Topic{Name: a.config.EventTopic}))

 	// Create the open OLT adapter
 	if a.iAdapter, err = a.startOpenOLT(ctx, a.kip, a.coreProxy, a.adapterProxy, a.eventProxy, a.config); err != nil {
 		logger.Fatalw(ctx, "error-starting-openolt", log.Fields{"error": err})
 	}

 	// Register the core request handler
 	if err = a.setupRequestHandler(ctx, a.instanceID, a.iAdapter); err != nil {
 		logger.Fatalw(ctx, "error-setting-core-request-handler", log.Fields{"error": err})
 	}

 	// Register this adapter to the Core - retries indefinitely
 	if err = a.registerWithCore(ctx, -1); err != nil {
 		logger.Fatal(ctx, "error-registering-with-core")
 	}

 	// check the readiness and liveliness and update the probe status
 	a.checkServicesReadiness(ctx)
 }

 /**
 This function checks the liveliness and readiness of the kakfa and kv-client services
 and update the status in the probe.
 */
 func (a *adapter) checkServicesReadiness(ctx context.Context) {
 	// checks the kafka readiness
 	go a.checkKafkaReadiness(ctx)

 	// checks the kv-store readiness
 	go a.checkKvStoreReadiness(ctx)
 }

 /**
 This function checks the liveliness and readiness of the kv-store service
 and update the status in the probe.
 */
 func (a *adapter) checkKvStoreReadiness(ctx context.Context) {
 	// dividing the live probe interval by 2 to get updated status every 30s
 	timeout := a.config.LiveProbeInterval / 2
 	kvStoreChannel := make(chan bool, 1)

 	// Default false to check the liveliness.
 	kvStoreChannel <- false
 	for {
 		timeoutTimer := time.NewTimer(timeout)
 		select {
 		case liveliness := <-kvStoreChannel:
 			if !liveliness {
 				// kv-store not reachable or down, updating the status to not ready state
 				probe.UpdateStatusFromContext(ctx, "kv-store", probe.ServiceStatusNotReady)
 				timeout = a.config.NotLiveProbeInterval
 			} else {
 				// kv-store is reachable , updating the status to running state
 				probe.UpdateStatusFromContext(ctx, "kv-store", probe.ServiceStatusRunning)
 				timeout = a.config.LiveProbeInterval / 2
 			}
 			// Check if the timer has expired or not
 			if !timeoutTimer.Stop() {
 				<-timeoutTimer.C
 			}
 		case <-timeoutTimer.C:
 			// Check the status of the kv-store. Use timeout of 2 seconds to avoid forever blocking
 			logger.Info(ctx, "kv-store liveliness-recheck")
 			timeoutCtx, cancelFunc := context.WithTimeout(ctx, 2*time.Second)

 			kvStoreChannel <- a.kvClient.IsConnectionUp(timeoutCtx)
 			// Cleanup cancel func resources
 			cancelFunc()
 		}
 	}
 }

 /**
 This function checks the liveliness and readiness of the kafka service
 and update the status in the probe.
 */
 func (a *adapter) checkKafkaReadiness(ctx context.Context) {
 	livelinessChannel := a.kafkaClient.EnableLivenessChannel(ctx, true)
 	healthinessChannel := a.kafkaClient.EnableHealthinessChannel(ctx, true)
 	timeout := a.config.LiveProbeInterval
 	failed := false
 	for {
 		timeoutTimer := time.NewTimer(timeout)

 		select {
 		case healthiness := <-healthinessChannel:
 			if !healthiness {
 				// This will eventually cause K8s to restart the container, and will do
 				// so in a way that allows cleanup to continue, rather than an immediate
 				// panic and exit here.
 				probe.UpdateStatusFromContext(ctx, "message-bus", probe.ServiceStatusFailed)
 				failed = true
 			}
 			// Check if the timer has expired or not
 			if !timeoutTimer.Stop() {
 				<-timeoutTimer.C
 			}
 		case liveliness := <-livelinessChannel:
 			if failed {
 				// Failures of the message bus are permanent and can't ever be recovered from,
 				// so make sure we never inadvertently reset a failed state back to unready.
 			} else if !liveliness {
 				// kafka not reachable or down, updating the status to not ready state
 				probe.UpdateStatusFromContext(ctx, "message-bus", probe.ServiceStatusNotReady)
 				timeout = a.config.NotLiveProbeInterval
 			} else {
 				// kafka is reachable , updating the status to running state
 				probe.UpdateStatusFromContext(ctx, "message-bus", probe.ServiceStatusRunning)
 				timeout = a.config.LiveProbeInterval
 			}
 			// Check if the timer has expired or not
 			if !timeoutTimer.Stop() {
 				<-timeoutTimer.C
 			}
 		case <-timeoutTimer.C:
 			logger.Info(ctx, "kafka-proxy-liveness-recheck")
 			// send the liveness probe in a goroutine; we don't want to deadlock ourselves as
 			// the liveness probe may wait (and block) writing to our channel.
 			err := a.kafkaClient.SendLiveness(ctx)
 			if err != nil {
 				// Catch possible error case if sending liveness after Sarama has been stopped.
 				logger.Warnw(ctx, "error-kafka-send-liveness", log.Fields{"error": err})
 			}
 		}
 	}
 }

 func (a *adapter) stop(ctx context.Context) {
 	// Stop leadership tracking
 	a.halted = true

 	// send exit signal
 	a.exitChannel <- 0

 	// Cleanup - applies only if we had a kvClient
 	if a.kvClient != nil {
 		// Release all reservations
 		if err := a.kvClient.ReleaseAllReservations(ctx); err != nil {
 			logger.Infow(ctx, "fail-to-release-all-reservations", log.Fields{"error": err})
 		}
 		// Close the DB connection
 		a.kvClient.Close(ctx)
 	}

 	if a.kip != nil {
 		a.kip.Stop(ctx)
 	}

 	// TODO:  More cleanup
 }

 func newKVClient(ctx context.Context, storeType, address string, timeout time.Duration) (kvstore.Client, error) {

 	logger.Infow(ctx, "kv-store-type", log.Fields{"store": storeType})
 	switch storeType {
 	case "consul":
 		return kvstore.NewConsulClient(ctx, address, timeout)
 	case "etcd":
 		return kvstore.NewEtcdClient(ctx, address, timeout, log.FatalLevel)
 	}
 	return nil, errors.New("unsupported-kv-store")
 }

 func newKafkaClient(ctx context.Context, clientType, address string) (kafka.Client, error) {

 	logger.Infow(ctx, "common-client-type", log.Fields{"client": clientType})
 	switch clientType {
 	case "sarama":
 		return kafka.NewSaramaClient(
 			kafka.Address(address),
 			kafka.ProducerReturnOnErrors(true),
 			kafka.ProducerReturnOnSuccess(true),
 			kafka.ProducerMaxRetries(6),
 			kafka.ProducerRetryBackoff(time.Millisecond*30),
 			kafka.MetadatMaxRetries(15)), nil
 	}

 	return nil, errors.New("unsupported-client-type")
 }

 func (a *adapter) setKVClient(ctx context.Context) error {
 	client, err := newKVClient(ctx, a.config.KVStoreType, a.config.KVStoreAddress, a.config.KVStoreTimeout)
 	if err != nil {
 		a.kvClient = nil
 		return err
 	}
 	a.kvClient = client

 	return nil
 }

 func (a *adapter) startInterContainerProxy(ctx context.Context, retries int) (kafka.InterContainerProxy, error) {
 	logger.Infow(ctx, "starting-intercontainer-messaging-proxy", log.Fields{"address": a.config.KafkaAdapterAddress,
 		"topic": a.config.Topic})
 	var err error
 	kip := kafka.NewInterContainerProxy(
 		kafka.InterContainerAddress(a.config.KafkaAdapterAddress),
 		kafka.MsgClient(a.kafkaClient),
 		kafka.DefaultTopic(&kafka.Topic{Name: a.config.Topic}))
 	count := 0
 	for {
 		if err = kip.Start(ctx); err != nil {
 			logger.Warnw(ctx, "error-starting-messaging-proxy", log.Fields{"error": err})
 			if retries == count {
 				return nil, err
 			}
 			count = +1
 			// Take a nap before retrying
 			time.Sleep(2 * time.Second)
 		} else {
 			break
 		}
 	}
 	probe.UpdateStatusFromContext(ctx, "container-proxy", probe.ServiceStatusRunning)
 	logger.Info(ctx, "common-messaging-proxy-created")
 	return kip, nil
 }

 func (a *adapter) startOpenOLT(ctx context.Context, kip kafka.InterContainerProxy,
 	cp adapterif.CoreProxy, ap adapterif.AdapterProxy, ep adapterif.EventProxy,
 	cfg *config.AdapterFlags) (*ac.OpenOLT, error) {
 	logger.Info(ctx, "starting-open-olt")
 	var err error
 	sOLT := ac.NewOpenOLT(ctx, a.kip, cp, ap, ep, cfg)

 	if err = sOLT.Start(ctx); err != nil {
 		return nil, err
 	}

 	logger.Info(ctx, "open-olt-started")
 	return sOLT, nil
 }

 func (a *adapter) setupRequestHandler(ctx context.Context, coreInstanceID string, iadapter adapters.IAdapter) error {
 	logger.Info(ctx, "setting-request-handler")
 	requestProxy := com.NewRequestHandlerProxy(coreInstanceID, iadapter, a.coreProxy)
 	if err := a.kip.SubscribeWithRequestHandlerInterface(ctx, kafka.Topic{Name: a.config.Topic}, requestProxy); err != nil {
 		return err

 	}
 	probe.UpdateStatusFromContext(ctx, "core-request-handler", probe.ServiceStatusRunning)
 	logger.Info(ctx, "request-handler-setup-done")
 	return nil
 }

 func (a *adapter) registerWithCore(ctx context.Context, retries int) error {
 	adapterID := fmt.Sprintf("eponolt_%d", a.config.CurrentReplica)
 	logger.Infow(ctx, "registering-with-core", log.Fields{
 		"adapterID":      adapterID,
 		"currentReplica": a.config.CurrentReplica,
 		"totalReplicas":  a.config.TotalReplicas,
 	})
 	adapterDescription := &voltha.Adapter{
 		Id:      adapterID, // Unique name for the device type
 		Vendor:  "VOLTHA EPON OLT",
 		Version: version.VersionInfo.Version,
 		// TODO once we'll be ready to support multiple versions of the OpenOLT adapter
 		// the Endpoint will have to change to `openolt_<currentReplica`>
 		Endpoint:       a.config.Topic,
 		Type:           "eponolt",
 		CurrentReplica: int32(a.config.CurrentReplica),
 		TotalReplicas:  int32(a.config.TotalReplicas),
 	}
 	types := []*voltha.DeviceType{{
 		Id:                          "eponolt",
 		Adapter:                     "eponolt", // Type of the adapter that handles device type
 		AcceptsBulkFlowUpdate:       false,     // Currently openolt adapter does not support bulk flow handling
 		AcceptsAddRemoveFlowUpdates: true}}
 	deviceTypes := &voltha.DeviceTypes{Items: types}
 	count := 0
 	for {
 		if err := a.coreProxy.RegisterAdapter(log.WithSpanFromContext(context.TODO(), ctx), adapterDescription, deviceTypes); err != nil {
 			logger.Warnw(ctx, "registering-with-core-failed", log.Fields{"error": err})
 			if retries == count {
 				return err
 			}
 			count++
 			// Take a nap before retrying
 			time.Sleep(2 * time.Second)
 		} else {
 			break
 		}
 	}
 	probe.UpdateStatusFromContext(ctx, "register-with-core", probe.ServiceStatusRunning)
 	logger.Info(ctx, "registered-with-core")
 	return nil
 }

 func waitForExit(ctx context.Context) int {
 	signalChannel := make(chan os.Signal, 1)
 	signal.Notify(signalChannel,
 		syscall.SIGHUP,
 		syscall.SIGINT,
 		syscall.SIGTERM,
 		syscall.SIGQUIT)

 	exitChannel := make(chan int)

 	go func() {
 		s := <-signalChannel
 		switch s {
 		case syscall.SIGHUP,
 			syscall.SIGINT,
 			syscall.SIGTERM,
 			syscall.SIGQUIT:
 			logger.Infow(ctx, "closing-signal-received", log.Fields{"signal": s})
 			exitChannel <- 0
 		default:
 			logger.Infow(ctx, "unexpected-signal-received", log.Fields{"signal": s})
 			exitChannel <- 1
 		}
 	}()

 	code := <-exitChannel
 	return code
 }

 func printBanner() {
   fmt.Println(`  _____ ____   ____  __    _  ____  _   _______   `)
   fmt.Println(` | ____|  _ \ / __ \|  \  | |/ __ \| | |__   __|  `)
   fmt.Println(` | |___| |_| | |  | |   \ | | |  | | |    | |     `)
   fmt.Println(` |  ___|  __/| |  | | |\ \| | |  | | |    | |     `)
   fmt.Println(` | |___| |   | |__| | | \   | |__| | |____| |     `)
   fmt.Println(` |_____|_|    \____/|_|  \__|\____/|______|_|     `)
 }


 func printVersion() {
 	fmt.Println("VOLTHA OpenOLT Adapter")
 	fmt.Println(version.VersionInfo.String("  "))
 }

 func main() {
 	ctx := context.Background()
 	start := time.Now()

 	cf := config.NewAdapterFlags()
 	cf.ParseCommandArguments()

 	// Setup logging

 	logLevel, err := log.StringToLogLevel(cf.LogLevel)
 	if err != nil {
 		logger.Fatalf(ctx, "Cannot setup logging, %s", err)
 	}

 	// Setup default logger - applies for packages that do not have specific logger set
 	if _, err := log.SetDefaultLogger(log.JSON, logLevel, log.Fields{"instanceId": cf.InstanceID}); err != nil {
 		logger.With(log.Fields{"error": err}).Fatal(ctx, "Cannot setup logging")
 	}

 	// Update all loggers (provisionned via init) with a common field
 	if err := log.UpdateAllLoggers(log.Fields{"instanceId": cf.InstanceID}); err != nil {
 		logger.With(log.Fields{"error": err}).Fatal(ctx, "Cannot setup logging")
 	}

 	log.SetAllLogLevel(logLevel)

 	realMain()

 	defer func() {
 		err := log.CleanUp()
 		if err != nil {
 			logger.Errorw(context.Background(), "unable-to-flush-any-buffered-log-entries", log.Fields{"error": err})
 		}
 	}()

 	// Print version / build information and exit
 	if cf.DisplayVersionOnly {
 		printVersion()
 		return
 	}

 	// Print banner if specified
 	if cf.Banner {
 		printBanner()
 	}

 	logger.Infow(ctx, "config", log.Fields{"config": *cf})

 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()

 	ad := newAdapter(cf)

 	p := &probe.Probe{}
 	go p.ListenAndServe(ctx, ad.config.ProbeAddress)

 	probeCtx := context.WithValue(ctx, probe.ProbeContextKey, p)

 	closer, err := log.GetGlobalLFM().InitTracingAndLogCorrelation(cf.TraceEnabled, cf.TraceAgentAddress, cf.LogCorrelationEnabled)
 	if err != nil {
 		logger.Warnw(ctx, "unable-to-initialize-tracing-and-log-correlation-module", log.Fields{"error": err})
 	} else {
 		defer log.TerminateTracing(closer)
 	}

 	go ad.start(probeCtx)

 	code := waitForExit(ctx)
 	logger.Infow(ctx, "received-a-closing-signal", log.Fields{"code": code})

 	// Cleanup before leaving
 	ad.stop(ctx)

 	elapsed := time.Since(start)
 	logger.Infow(ctx, "run-time", log.Fields{"instanceId": ad.config.InstanceID, "time": elapsed / time.Second})
 }
	/*
	* Copyright 2018-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 main invokes the application
	package main

	import (
	"context"
	"errors"
	"fmt"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/opencord/voltha-lib-go/v3/pkg/adapters/adapterif"

	"github.com/opencord/voltha-lib-go/v3/pkg/adapters"
	com "github.com/opencord/voltha-lib-go/v3/pkg/adapters/common"
	conf "github.com/opencord/voltha-lib-go/v3/pkg/config"
	"github.com/opencord/voltha-lib-go/v3/pkg/db/kvstore"
	"github.com/opencord/voltha-lib-go/v3/pkg/kafka"
	"github.com/opencord/voltha-lib-go/v3/pkg/log"
	"github.com/opencord/voltha-lib-go/v3/pkg/probe"
	"github.com/opencord/voltha-lib-go/v3/pkg/version"
	"github.com/opencord/voltha-openolt-adapter/internal/pkg/config"
	ac "github.com/opencord/voltha-openolt-adapter/internal/pkg/core"
	ic "github.com/opencord/voltha-protos/v3/go/inter_container"
	"github.com/opencord/voltha-protos/v3/go/voltha"
	)

	type adapter struct {
	instanceID string
	config *config.AdapterFlags
	iAdapter adapters.IAdapter
	kafkaClient kafka.Client
	kvClient kvstore.Client
	kip kafka.InterContainerProxy
	coreProxy adapterif.CoreProxy
	adapterProxy adapterif.AdapterProxy
	eventProxy adapterif.EventProxy
	halted bool
	exitChannel chan int
	receiverChannels []<-chan *ic.InterContainerMessage
	}

	func newAdapter(cf config.AdapterFlags) adapter {
	var a adapter
	a.instanceID = cf.InstanceID
	a.config = cf
	a.halted = false
	a.exitChannel = make(chan int, 1)
	a.receiverChannels = make([]<-chan *ic.InterContainerMessage, 0)
	return &a
	}

	func (a *adapter) start(ctx context.Context) {
	logger.Info(ctx, "Starting Core Adapter components")
	var err error

	var p *probe.Probe
	if value := ctx.Value(probe.ProbeContextKey); value != nil {
	if _, ok := value.(*probe.Probe); ok {
	p = value.(*probe.Probe)
	p.RegisterService(
	ctx,
	"message-bus",
	"kv-store",
	"container-proxy",
	"core-request-handler",
	"register-with-core",
	)
	}
	}

	// Setup KV Client
	logger.Debugw(ctx, "create-kv-client", log.Fields{"kvstore": a.config.KVStoreType})
	if err = a.setKVClient(ctx); err != nil {
	logger.Fatalw(ctx, "error-setting-kv-client", log.Fields{"error": err})
	}

	if p != nil {
	p.UpdateStatus(ctx, "kv-store", probe.ServiceStatusRunning)
	}

	// Setup Log Config
	cm := conf.NewConfigManager(ctx, a.kvClient, a.config.KVStoreType, a.config.KVStoreAddress, a.config.KVStoreTimeout)
	go conf.StartLogLevelConfigProcessing(cm, ctx)
	go conf.StartLogFeaturesConfigProcessing(cm, ctx)

	// Setup Kafka Client
	if a.kafkaClient, err = newKafkaClient(ctx, "sarama", a.config.KafkaAdapterAddress); err != nil {
	logger.Fatalw(ctx, "Unsupported-common-client", log.Fields{"error": err})
	}

	if p != nil {
	p.UpdateStatus(ctx, "message-bus", probe.ServiceStatusRunning)
	}

	// setup endpointManager

	// Start the common InterContainer Proxy - retries indefinitely
	if a.kip, err = a.startInterContainerProxy(ctx, -1); err != nil {
	logger.Fatal(ctx, "error-starting-inter-container-proxy")
	}

	// Create the core proxy to handle requests to the Core
	a.coreProxy = com.NewCoreProxy(ctx, a.kip, a.config.Topic, a.config.CoreTopic)

	// Create the adaptor proxy to handle request between olt and onu
	a.adapterProxy = com.NewAdapterProxy(ctx, a.kip, a.config.CoreTopic, cm.Backend)

	// Create the event proxy to post events to KAFKA
	a.eventProxy = com.NewEventProxy(com.MsgClient(a.kafkaClient), com.MsgTopic(kafka.Topic{Name: a.config.EventTopic}))

	// Create the open OLT adapter
	if a.iAdapter, err = a.startOpenOLT(ctx, a.kip, a.coreProxy, a.adapterProxy, a.eventProxy, a.config); err != nil {
	logger.Fatalw(ctx, "error-starting-openolt", log.Fields{"error": err})
	}

	// Register the core request handler
	if err = a.setupRequestHandler(ctx, a.instanceID, a.iAdapter); err != nil {
	logger.Fatalw(ctx, "error-setting-core-request-handler", log.Fields{"error": err})
	}

	// Register this adapter to the Core - retries indefinitely
	if err = a.registerWithCore(ctx, -1); err != nil {
	logger.Fatal(ctx, "error-registering-with-core")
	}

	// check the readiness and liveliness and update the probe status
	a.checkServicesReadiness(ctx)
	}

	/**
	This function checks the liveliness and readiness of the kakfa and kv-client services
	and update the status in the probe.
	*/
	func (a *adapter) checkServicesReadiness(ctx context.Context) {
	// checks the kafka readiness
	go a.checkKafkaReadiness(ctx)

	// checks the kv-store readiness
	go a.checkKvStoreReadiness(ctx)
	}

	/**
	This function checks the liveliness and readiness of the kv-store service
	and update the status in the probe.
	*/
	func (a *adapter) checkKvStoreReadiness(ctx context.Context) {
	// dividing the live probe interval by 2 to get updated status every 30s
	timeout := a.config.LiveProbeInterval / 2
	kvStoreChannel := make(chan bool, 1)

	// Default false to check the liveliness.
	kvStoreChannel <- false
	for {
	timeoutTimer := time.NewTimer(timeout)
	select {
	case liveliness := <-kvStoreChannel:
	if !liveliness {
	// kv-store not reachable or down, updating the status to not ready state
	probe.UpdateStatusFromContext(ctx, "kv-store", probe.ServiceStatusNotReady)
	timeout = a.config.NotLiveProbeInterval
	} else {
	// kv-store is reachable , updating the status to running state
	probe.UpdateStatusFromContext(ctx, "kv-store", probe.ServiceStatusRunning)
	timeout = a.config.LiveProbeInterval / 2
	}
	// Check if the timer has expired or not
	if !timeoutTimer.Stop() {
	<-timeoutTimer.C
	}
	case <-timeoutTimer.C:
	// Check the status of the kv-store. Use timeout of 2 seconds to avoid forever blocking
	logger.Info(ctx, "kv-store liveliness-recheck")
	timeoutCtx, cancelFunc := context.WithTimeout(ctx, 2*time.Second)

	kvStoreChannel <- a.kvClient.IsConnectionUp(timeoutCtx)
	// Cleanup cancel func resources
	cancelFunc()
	}
	}
	}

	/**
	This function checks the liveliness and readiness of the kafka service
	and update the status in the probe.
	*/
	func (a *adapter) checkKafkaReadiness(ctx context.Context) {
	livelinessChannel := a.kafkaClient.EnableLivenessChannel(ctx, true)
	healthinessChannel := a.kafkaClient.EnableHealthinessChannel(ctx, true)
	timeout := a.config.LiveProbeInterval
	failed := false
	for {
	timeoutTimer := time.NewTimer(timeout)

	select {
	case healthiness := <-healthinessChannel:
	if !healthiness {
	// This will eventually cause K8s to restart the container, and will do
	// so in a way that allows cleanup to continue, rather than an immediate
	// panic and exit here.
	probe.UpdateStatusFromContext(ctx, "message-bus", probe.ServiceStatusFailed)
	failed = true
	}
	// Check if the timer has expired or not
	if !timeoutTimer.Stop() {
	<-timeoutTimer.C
	}
	case liveliness := <-livelinessChannel:
	if failed {
	// Failures of the message bus are permanent and can't ever be recovered from,
	// so make sure we never inadvertently reset a failed state back to unready.
	} else if !liveliness {
	// kafka not reachable or down, updating the status to not ready state
	probe.UpdateStatusFromContext(ctx, "message-bus", probe.ServiceStatusNotReady)
	timeout = a.config.NotLiveProbeInterval
	} else {
	// kafka is reachable , updating the status to running state
	probe.UpdateStatusFromContext(ctx, "message-bus", probe.ServiceStatusRunning)
	timeout = a.config.LiveProbeInterval
	}
	// Check if the timer has expired or not
	if !timeoutTimer.Stop() {
	<-timeoutTimer.C
	}
	case <-timeoutTimer.C:
	logger.Info(ctx, "kafka-proxy-liveness-recheck")
	// send the liveness probe in a goroutine; we don't want to deadlock ourselves as
	// the liveness probe may wait (and block) writing to our channel.
	err := a.kafkaClient.SendLiveness(ctx)
	if err != nil {
	// Catch possible error case if sending liveness after Sarama has been stopped.
	logger.Warnw(ctx, "error-kafka-send-liveness", log.Fields{"error": err})
	}
	}
	}
	}

	func (a *adapter) stop(ctx context.Context) {
	// Stop leadership tracking
	a.halted = true

	// send exit signal
	a.exitChannel <- 0

	// Cleanup - applies only if we had a kvClient
	if a.kvClient != nil {
	// Release all reservations
	if err := a.kvClient.ReleaseAllReservations(ctx); err != nil {
	logger.Infow(ctx, "fail-to-release-all-reservations", log.Fields{"error": err})
	}
	// Close the DB connection
	a.kvClient.Close(ctx)
	}

	if a.kip != nil {
	a.kip.Stop(ctx)
	}

	// TODO: More cleanup
	}

	func newKVClient(ctx context.Context, storeType, address string, timeout time.Duration) (kvstore.Client, error) {

	logger.Infow(ctx, "kv-store-type", log.Fields{"store": storeType})
	switch storeType {
	case "consul":
	return kvstore.NewConsulClient(ctx, address, timeout)
	case "etcd":
	return kvstore.NewEtcdClient(ctx, address, timeout, log.FatalLevel)
	}
	return nil, errors.New("unsupported-kv-store")
	}

	func newKafkaClient(ctx context.Context, clientType, address string) (kafka.Client, error) {

	logger.Infow(ctx, "common-client-type", log.Fields{"client": clientType})
	switch clientType {
	case "sarama":
	return kafka.NewSaramaClient(
	kafka.Address(address),
	kafka.ProducerReturnOnErrors(true),
	kafka.ProducerReturnOnSuccess(true),
	kafka.ProducerMaxRetries(6),
	kafka.ProducerRetryBackoff(time.Millisecond*30),
	kafka.MetadatMaxRetries(15)), nil
	}

	return nil, errors.New("unsupported-client-type")
	}

	func (a *adapter) setKVClient(ctx context.Context) error {
	client, err := newKVClient(ctx, a.config.KVStoreType, a.config.KVStoreAddress, a.config.KVStoreTimeout)
	if err != nil {
	a.kvClient = nil
	return err
	}
	a.kvClient = client

	return nil
	}

	func (a *adapter) startInterContainerProxy(ctx context.Context, retries int) (kafka.InterContainerProxy, error) {
	logger.Infow(ctx, "starting-intercontainer-messaging-proxy", log.Fields{"address": a.config.KafkaAdapterAddress,
	"topic": a.config.Topic})
	var err error
	kip := kafka.NewInterContainerProxy(
	kafka.InterContainerAddress(a.config.KafkaAdapterAddress),
	kafka.MsgClient(a.kafkaClient),
	kafka.DefaultTopic(&kafka.Topic{Name: a.config.Topic}))
	count := 0
	for {
	if err = kip.Start(ctx); err != nil {
	logger.Warnw(ctx, "error-starting-messaging-proxy", log.Fields{"error": err})
	if retries == count {
	return nil, err
	}
	count = +1
	// Take a nap before retrying
	time.Sleep(2 * time.Second)
	} else {
	break
	}
	}
	probe.UpdateStatusFromContext(ctx, "container-proxy", probe.ServiceStatusRunning)
	logger.Info(ctx, "common-messaging-proxy-created")
	return kip, nil
	}

	func (a *adapter) startOpenOLT(ctx context.Context, kip kafka.InterContainerProxy,
	cp adapterif.CoreProxy, ap adapterif.AdapterProxy, ep adapterif.EventProxy,
	cfg config.AdapterFlags) (ac.OpenOLT, error) {
	logger.Info(ctx, "starting-open-olt")
	var err error
	sOLT := ac.NewOpenOLT(ctx, a.kip, cp, ap, ep, cfg)

	if err = sOLT.Start(ctx); err != nil {
	return nil, err
	}

	logger.Info(ctx, "open-olt-started")
	return sOLT, nil
	}

	func (a *adapter) setupRequestHandler(ctx context.Context, coreInstanceID string, iadapter adapters.IAdapter) error {
	logger.Info(ctx, "setting-request-handler")
	requestProxy := com.NewRequestHandlerProxy(coreInstanceID, iadapter, a.coreProxy)
	if err := a.kip.SubscribeWithRequestHandlerInterface(ctx, kafka.Topic{Name: a.config.Topic}, requestProxy); err != nil {
	return err

	}
	probe.UpdateStatusFromContext(ctx, "core-request-handler", probe.ServiceStatusRunning)
	logger.Info(ctx, "request-handler-setup-done")
	return nil
	}

	func (a *adapter) registerWithCore(ctx context.Context, retries int) error {
	adapterID := fmt.Sprintf("eponolt_%d", a.config.CurrentReplica)
	logger.Infow(ctx, "registering-with-core", log.Fields{
	"adapterID": adapterID,
	"currentReplica": a.config.CurrentReplica,
	"totalReplicas": a.config.TotalReplicas,
	})
	adapterDescription := &voltha.Adapter{
	Id: adapterID, // Unique name for the device type
	Vendor: "VOLTHA EPON OLT",
	Version: version.VersionInfo.Version,
	// TODO once we'll be ready to support multiple versions of the OpenOLT adapter
	// the Endpoint will have to change to `openolt_<currentReplica`>
	Endpoint: a.config.Topic,
	Type: "eponolt",
	CurrentReplica: int32(a.config.CurrentReplica),
	TotalReplicas: int32(a.config.TotalReplicas),
	}
	types := []*voltha.DeviceType{{
	Id: "eponolt",
	Adapter: "eponolt", // Type of the adapter that handles device type
	AcceptsBulkFlowUpdate: false, // Currently openolt adapter does not support bulk flow handling
	AcceptsAddRemoveFlowUpdates: true}}
	deviceTypes := &voltha.DeviceTypes{Items: types}
	count := 0
	for {
	if err := a.coreProxy.RegisterAdapter(log.WithSpanFromContext(context.TODO(), ctx), adapterDescription, deviceTypes); err != nil {
	logger.Warnw(ctx, "registering-with-core-failed", log.Fields{"error": err})
	if retries == count {
	return err
	}
	count++
	// Take a nap before retrying
	time.Sleep(2 * time.Second)
	} else {
	break
	}
	}
	probe.UpdateStatusFromContext(ctx, "register-with-core", probe.ServiceStatusRunning)
	logger.Info(ctx, "registered-with-core")
	return nil
	}

	func waitForExit(ctx context.Context) int {
	signalChannel := make(chan os.Signal, 1)
	signal.Notify(signalChannel,
	syscall.SIGHUP,
	syscall.SIGINT,
	syscall.SIGTERM,
	syscall.SIGQUIT)

	exitChannel := make(chan int)

	go func() {
	s := <-signalChannel
	switch s {
	case syscall.SIGHUP,
	syscall.SIGINT,
	syscall.SIGTERM,
	syscall.SIGQUIT:
	logger.Infow(ctx, "closing-signal-received", log.Fields{"signal": s})
	exitChannel <- 0
	default:
	logger.Infow(ctx, "unexpected-signal-received", log.Fields{"signal": s})
	exitChannel <- 1
	}
	}()

	code := <-exitChannel
	return code
	}

	func printBanner() {
	fmt.Println(` _____ ____ ____ __ _ ____ _ _______ `)
	fmt.Println(` \| ____\| _ \ / __ \\| \ \| \|/ __ \\| \| \|__ __\| `)
	fmt.Println(` \| \|___\| \|_\| \| \| \| \| \ \| \| \| \| \| \| \| \| `)
	fmt.Println(` \| ___\| __/\| \| \| \| \|\ \\| \| \| \| \| \| \| \| `)
	fmt.Println(` \| \|___\| \| \| \|__\| \| \| \ \| \|__\| \| \|____\| \| `)
	fmt.Println(` \|_____\|_\| \____/\|_\| \__\|\____/\|______\|_\| `)
	}



	func printVersion() {
	fmt.Println("VOLTHA OpenOLT Adapter")
	fmt.Println(version.VersionInfo.String(" "))
	}

	func main() {
	ctx := context.Background()
	start := time.Now()

	cf := config.NewAdapterFlags()
	cf.ParseCommandArguments()

	// Setup logging

	logLevel, err := log.StringToLogLevel(cf.LogLevel)
	if err != nil {
	logger.Fatalf(ctx, "Cannot setup logging, %s", err)
	}

	// Setup default logger - applies for packages that do not have specific logger set
	if _, err := log.SetDefaultLogger(log.JSON, logLevel, log.Fields{"instanceId": cf.InstanceID}); err != nil {
	logger.With(log.Fields{"error": err}).Fatal(ctx, "Cannot setup logging")
	}

	// Update all loggers (provisionned via init) with a common field
	if err := log.UpdateAllLoggers(log.Fields{"instanceId": cf.InstanceID}); err != nil {
	logger.With(log.Fields{"error": err}).Fatal(ctx, "Cannot setup logging")
	}

	log.SetAllLogLevel(logLevel)

	realMain()

	defer func() {
	err := log.CleanUp()
	if err != nil {
	logger.Errorw(context.Background(), "unable-to-flush-any-buffered-log-entries", log.Fields{"error": err})
	}
	}()

	// Print version / build information and exit
	if cf.DisplayVersionOnly {
	printVersion()
	return
	}

	// Print banner if specified
	if cf.Banner {
	printBanner()
	}

	logger.Infow(ctx, "config", log.Fields{"config": *cf})

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	ad := newAdapter(cf)

	p := &probe.Probe{}
	go p.ListenAndServe(ctx, ad.config.ProbeAddress)

	probeCtx := context.WithValue(ctx, probe.ProbeContextKey, p)

	closer, err := log.GetGlobalLFM().InitTracingAndLogCorrelation(cf.TraceEnabled, cf.TraceAgentAddress, cf.LogCorrelationEnabled)
	if err != nil {
	logger.Warnw(ctx, "unable-to-initialize-tracing-and-log-correlation-module", log.Fields{"error": err})
	} else {
	defer log.TerminateTracing(closer)
	}

	go ad.start(probeCtx)

	code := waitForExit(ctx)
	logger.Infow(ctx, "received-a-closing-signal", log.Fields{"code": code})

	// Cleanup before leaving
	ad.stop(ctx)

	elapsed := time.Since(start)
	logger.Infow(ctx, "run-time", log.Fields{"instanceId": ad.config.InstanceID, "time": elapsed / time.Second})
	}