| /* |
| * Copyright 2021-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 grpc |
| |
| import ( |
| "context" |
| "fmt" |
| "reflect" |
| "strings" |
| "sync" |
| "time" |
| |
| grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware" |
| grpc_opentracing "github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing" |
| "github.com/opencord/voltha-lib-go/v7/pkg/log" |
| "github.com/opencord/voltha-lib-go/v7/pkg/probe" |
| "github.com/opencord/voltha-protos/v5/go/adapter_services" |
| "github.com/opencord/voltha-protos/v5/go/core" |
| "google.golang.org/grpc" |
| "google.golang.org/grpc/keepalive" |
| ) |
| |
| type event byte |
| type state byte |
| type SetAndTestServiceHandler func(context.Context, *grpc.ClientConn) interface{} |
| type RestartedHandler func(ctx context.Context, endPoint string) error |
| |
| type contextKey string |
| |
| func (c contextKey) String() string { |
| return string(c) |
| } |
| |
| var ( |
| grpcMonitorContextKey = contextKey("grpc-monitor") |
| ) |
| |
| const ( |
| grpcBackoffInitialInterval = "GRPC_BACKOFF_INITIAL_INTERVAL" |
| grpcBackoffMaxInterval = "GRPC_BACKOFF_MAX_INTERVAL" |
| grpcBackoffMaxElapsedTime = "GRPC_BACKOFF_MAX_ELAPSED_TIME" |
| grpcMonitorInterval = "GRPC_MONITOR_INTERVAL" |
| ) |
| |
| const ( |
| DefaultBackoffInitialInterval = 100 * time.Millisecond |
| DefaultBackoffMaxInterval = 5 * time.Second |
| DefaultBackoffMaxElapsedTime = 0 * time.Second // No time limit |
| DefaultGRPCMonitorInterval = 5 * time.Second |
| ) |
| |
| const ( |
| connectionErrorSubString = "SubConns are in TransientFailure" |
| connectionClosedSubstring = "client connection is closing" |
| connectionError = "connection error" |
| connectionSystemNotReady = "system is not ready" |
| ) |
| |
| const ( |
| eventConnecting = event(iota) |
| eventConnected |
| eventDisconnected |
| eventStopped |
| eventError |
| |
| stateConnected = state(iota) |
| stateConnecting |
| stateDisconnected |
| ) |
| |
| type Client struct { |
| apiEndPoint string |
| connection *grpc.ClientConn |
| connectionLock sync.RWMutex |
| stateLock sync.RWMutex |
| state state |
| service interface{} |
| events chan event |
| onRestart RestartedHandler |
| backoffInitialInterval time.Duration |
| backoffMaxInterval time.Duration |
| backoffMaxElapsedTime time.Duration |
| activityCheck bool |
| monitorInterval time.Duration |
| activeCh chan struct{} |
| activeChMutex sync.RWMutex |
| done bool |
| livenessCallback func(timestamp time.Time) |
| } |
| |
| type ClientOption func(*Client) |
| |
| func ActivityCheck(enable bool) ClientOption { |
| return func(args *Client) { |
| args.activityCheck = enable |
| } |
| } |
| |
| func NewClient(endpoint string, onRestart RestartedHandler, opts ...ClientOption) (*Client, error) { |
| c := &Client{ |
| apiEndPoint: endpoint, |
| onRestart: onRestart, |
| events: make(chan event, 1), |
| state: stateDisconnected, |
| backoffInitialInterval: DefaultBackoffInitialInterval, |
| backoffMaxInterval: DefaultBackoffMaxInterval, |
| backoffMaxElapsedTime: DefaultBackoffMaxElapsedTime, |
| monitorInterval: DefaultGRPCMonitorInterval, |
| } |
| for _, option := range opts { |
| option(c) |
| } |
| |
| // Check for environment variables |
| if err := SetFromEnvVariable(grpcBackoffInitialInterval, &c.backoffInitialInterval); err != nil { |
| logger.Warnw(context.Background(), "failure-reading-env-variable", log.Fields{"error": err, "variable": grpcBackoffInitialInterval}) |
| } |
| |
| if err := SetFromEnvVariable(grpcBackoffMaxInterval, &c.backoffMaxInterval); err != nil { |
| logger.Warnw(context.Background(), "failure-reading-env-variable", log.Fields{"error": err, "variable": grpcBackoffMaxInterval}) |
| } |
| |
| if err := SetFromEnvVariable(grpcBackoffMaxElapsedTime, &c.backoffMaxElapsedTime); err != nil { |
| logger.Warnw(context.Background(), "failure-reading-env-variable", log.Fields{"error": err, "variable": grpcBackoffMaxElapsedTime}) |
| } |
| |
| if err := SetFromEnvVariable(grpcMonitorInterval, &c.monitorInterval); err != nil { |
| logger.Warnw(context.Background(), "failure-reading-env-variable", log.Fields{"error": err, "variable": grpcMonitorInterval}) |
| } |
| |
| logger.Infow(context.Background(), "initialized-client", log.Fields{"client": c}) |
| |
| // Sanity check |
| if c.backoffInitialInterval > c.backoffMaxInterval { |
| return nil, fmt.Errorf("initial retry delay %v is greater than maximum retry delay %v", c.backoffInitialInterval, c.backoffMaxInterval) |
| } |
| |
| return c, nil |
| } |
| |
| func (c *Client) GetClient() (interface{}, error) { |
| c.connectionLock.RLock() |
| defer c.connectionLock.RUnlock() |
| if c.service == nil { |
| return nil, fmt.Errorf("no connection to %s", c.apiEndPoint) |
| } |
| return c.service, nil |
| } |
| |
| // GetCoreServiceClient is a helper function that returns a concrete service instead of the GetClient() API |
| // which returns an interface |
| func (c *Client) GetCoreServiceClient() (core.CoreServiceClient, error) { |
| c.connectionLock.RLock() |
| defer c.connectionLock.RUnlock() |
| if c.service == nil { |
| return nil, fmt.Errorf("no core connection to %s", c.apiEndPoint) |
| } |
| client, ok := c.service.(core.CoreServiceClient) |
| if ok { |
| return client, nil |
| } |
| return nil, fmt.Errorf("invalid-service-%s", reflect.TypeOf(c.service)) |
| } |
| |
| // GetOnuAdapterServiceClient is a helper function that returns a concrete service instead of the GetClient() API |
| // which returns an interface |
| func (c *Client) GetOnuInterAdapterServiceClient() (adapter_services.OnuInterAdapterServiceClient, error) { |
| c.connectionLock.RLock() |
| defer c.connectionLock.RUnlock() |
| if c.service == nil { |
| return nil, fmt.Errorf("no child adapter connection to %s", c.apiEndPoint) |
| } |
| client, ok := c.service.(adapter_services.OnuInterAdapterServiceClient) |
| if ok { |
| return client, nil |
| } |
| return nil, fmt.Errorf("invalid-service-%s", reflect.TypeOf(c.service)) |
| } |
| |
| // GetOltAdapterServiceClient is a helper function that returns a concrete service instead of the GetClient() API |
| // which returns an interface |
| func (c *Client) GetOltInterAdapterServiceClient() (adapter_services.OltInterAdapterServiceClient, error) { |
| c.connectionLock.RLock() |
| defer c.connectionLock.RUnlock() |
| if c.service == nil { |
| return nil, fmt.Errorf("no parent adapter connection to %s", c.apiEndPoint) |
| } |
| client, ok := c.service.(adapter_services.OltInterAdapterServiceClient) |
| if ok { |
| return client, nil |
| } |
| return nil, fmt.Errorf("invalid-service-%s", reflect.TypeOf(c.service)) |
| } |
| |
| func (c *Client) Reset(ctx context.Context) { |
| logger.Debugw(ctx, "resetting-client-connection", log.Fields{"endpoint": c.apiEndPoint}) |
| c.stateLock.Lock() |
| defer c.stateLock.Unlock() |
| if c.state == stateConnected { |
| c.state = stateDisconnected |
| c.events <- eventDisconnected |
| } |
| } |
| |
| func (c *Client) clientInterceptor(ctx context.Context, method string, req interface{}, reply interface{}, |
| cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error { |
| // Nothing to do before intercepting the call |
| err := invoker(ctx, method, req, reply, cc, opts...) |
| // On connection failure, start the reconnect process depending on the error response |
| if err != nil { |
| logger.Errorw(ctx, "received-error", log.Fields{"error": err, "context": ctx, "endpoint": c.apiEndPoint}) |
| if strings.Contains(err.Error(), connectionErrorSubString) || |
| strings.Contains(err.Error(), connectionError) || |
| strings.Contains(err.Error(), connectionSystemNotReady) || |
| isGrpcMonitorKeyPresentInContext(ctx) { |
| c.stateLock.Lock() |
| if c.state == stateConnected { |
| c.state = stateDisconnected |
| logger.Warnw(context.Background(), "sending-disconnect-event", log.Fields{"endpoint": c.apiEndPoint, "error": err, "curr-state": stateConnected, "new-state": c.state}) |
| c.events <- eventDisconnected |
| } |
| c.stateLock.Unlock() |
| } else if strings.Contains(err.Error(), connectionClosedSubstring) { |
| logger.Errorw(context.Background(), "invalid-client-connection-closed", log.Fields{"endpoint": c.apiEndPoint, "error": err}) |
| } |
| return err |
| } |
| // Update activity on success only |
| c.updateActivity(ctx) |
| return nil |
| } |
| |
| // updateActivity pushes an activity indication on the channel so that the monitoring routine does not validate |
| // the gRPC connection when the connection is being used. Note that this update is done both when the connection |
| // is alive or a connection error is returned. A separate routine takes care of doing the re-connect. |
| func (c *Client) updateActivity(ctx context.Context) { |
| c.activeChMutex.RLock() |
| defer c.activeChMutex.RUnlock() |
| if c.activeCh != nil { |
| logger.Debugw(ctx, "update-activity", log.Fields{"api-endpoint": c.apiEndPoint}) |
| c.activeCh <- struct{}{} |
| |
| // Update liveness only in connected state |
| if c.livenessCallback != nil { |
| c.stateLock.RLock() |
| if c.state == stateConnected { |
| c.livenessCallback(time.Now()) |
| } |
| c.stateLock.RUnlock() |
| } |
| } |
| } |
| |
| func WithGrpcMonitorContext(ctx context.Context, name string) context.Context { |
| ctx = context.WithValue(ctx, grpcMonitorContextKey, name) |
| return ctx |
| } |
| |
| func isGrpcMonitorKeyPresentInContext(ctx context.Context) bool { |
| if ctx != nil { |
| _, present := ctx.Value(grpcMonitorContextKey).(string) |
| return present |
| } |
| return false |
| } |
| |
| // monitorActivity monitors the activity on the gRPC connection. If there are no activity after a specified |
| // timeout, it will send a default API request on that connection. If the connection is good then nothing |
| // happens. If it's bad this will trigger reconnection attempts. |
| func (c *Client) monitorActivity(ctx context.Context, handler SetAndTestServiceHandler) { |
| logger.Infow(ctx, "start-activity-monitor", log.Fields{"endpoint": c.apiEndPoint}) |
| |
| // Create an activity monitor channel. Unbuffered channel works well. However, we use a buffered |
| // channel here as a safeguard of having the grpc interceptor publishing too many events that can be |
| // consumed by this monitoring thread |
| c.activeChMutex.Lock() |
| c.activeCh = make(chan struct{}, 10) |
| c.activeChMutex.Unlock() |
| |
| grpcMonitorCheckRunning := false |
| var grpcMonitorCheckRunningLock sync.RWMutex |
| |
| // Interval to wait for no activity before probing the connection |
| timeout := c.monitorInterval |
| loop: |
| for { |
| timeoutTimer := time.NewTimer(timeout) |
| select { |
| |
| case <-c.activeCh: |
| logger.Debugw(ctx, "endpoint-reachable", log.Fields{"endpoint": c.apiEndPoint}) |
| |
| // Reset timer |
| if !timeoutTimer.Stop() { |
| select { |
| case <-timeoutTimer.C: |
| default: |
| } |
| } |
| |
| case <-ctx.Done(): |
| break loop |
| |
| case <-timeoutTimer.C: |
| // Trigger an activity check if the state is connected. If the state is not connected then there is already |
| // a backoff retry mechanism in place to retry establishing connection. |
| c.stateLock.RLock() |
| grpcMonitorCheckRunningLock.RLock() |
| runCheck := (c.state == stateConnected) && !grpcMonitorCheckRunning |
| grpcMonitorCheckRunningLock.RUnlock() |
| c.stateLock.RUnlock() |
| if runCheck { |
| go func() { |
| grpcMonitorCheckRunningLock.Lock() |
| if grpcMonitorCheckRunning { |
| grpcMonitorCheckRunningLock.Unlock() |
| logger.Debugw(ctx, "connection-check-already-in-progress", log.Fields{"api-endpoint": c.apiEndPoint}) |
| return |
| } |
| grpcMonitorCheckRunning = true |
| grpcMonitorCheckRunningLock.Unlock() |
| |
| logger.Debugw(ctx, "connection-check-start", log.Fields{"api-endpoint": c.apiEndPoint}) |
| subCtx, cancel := context.WithTimeout(ctx, c.backoffMaxInterval) |
| defer cancel() |
| subCtx = WithGrpcMonitorContext(subCtx, "grpc-monitor") |
| c.connectionLock.RLock() |
| defer c.connectionLock.RUnlock() |
| if c.connection != nil { |
| response := handler(subCtx, c.connection) |
| logger.Debugw(ctx, "connection-check-response", log.Fields{"api-endpoint": c.apiEndPoint, "up": response != nil}) |
| } |
| grpcMonitorCheckRunningLock.Lock() |
| grpcMonitorCheckRunning = false |
| grpcMonitorCheckRunningLock.Unlock() |
| }() |
| } |
| } |
| } |
| logger.Infow(ctx, "activity-monitor-stopping", log.Fields{"endpoint": c.apiEndPoint}) |
| } |
| |
| // Start kicks off the adapter agent by trying to connect to the adapter |
| func (c *Client) Start(ctx context.Context, handler SetAndTestServiceHandler) { |
| logger.Debugw(ctx, "Starting GRPC - Client", log.Fields{"api-endpoint": c.apiEndPoint}) |
| |
| // If the context contains a k8s probe then register services |
| p := probe.GetProbeFromContext(ctx) |
| if p != nil { |
| p.RegisterService(ctx, c.apiEndPoint) |
| } |
| |
| // Enable activity check, if required |
| if c.activityCheck { |
| go c.monitorActivity(ctx, handler) |
| } |
| |
| initialConnection := true |
| c.events <- eventConnecting |
| backoff := NewBackoff(c.backoffInitialInterval, c.backoffMaxInterval, c.backoffMaxElapsedTime) |
| attempt := 1 |
| loop: |
| for { |
| select { |
| case <-ctx.Done(): |
| logger.Debugw(ctx, "context-closing", log.Fields{"endpoint": c.apiEndPoint}) |
| return |
| case event := <-c.events: |
| logger.Debugw(ctx, "received-event", log.Fields{"event": event, "endpoint": c.apiEndPoint}) |
| switch event { |
| case eventConnecting: |
| c.stateLock.Lock() |
| logger.Debugw(ctx, "connection-start", log.Fields{"endpoint": c.apiEndPoint, "attempts": attempt, "curr-state": c.state}) |
| if c.state == stateConnected { |
| c.state = stateDisconnected |
| } |
| if c.state != stateConnecting { |
| c.state = stateConnecting |
| go func() { |
| if err := c.connectToEndpoint(ctx, handler, p); err != nil { |
| c.stateLock.Lock() |
| c.state = stateDisconnected |
| c.stateLock.Unlock() |
| logger.Errorw(ctx, "connection-failed", log.Fields{"endpoint": c.apiEndPoint, "attempt": attempt, "error": err}) |
| |
| // Retry connection after a delay |
| if err = backoff.Backoff(ctx); err != nil { |
| // Context has closed or reached maximum elapsed time, if set |
| logger.Errorw(ctx, "retry-aborted", log.Fields{"endpoint": c.apiEndPoint, "error": err}) |
| return |
| } |
| attempt += 1 |
| c.events <- eventConnecting |
| } else { |
| backoff.Reset() |
| } |
| }() |
| } |
| c.stateLock.Unlock() |
| |
| case eventConnected: |
| attempt = 1 |
| c.stateLock.Lock() |
| logger.Debugw(ctx, "endpoint-connected", log.Fields{"endpoint": c.apiEndPoint, "curr-state": c.state}) |
| if c.state != stateConnected { |
| c.state = stateConnected |
| if initialConnection { |
| logger.Debugw(ctx, "initial-endpoint-connection", log.Fields{"endpoint": c.apiEndPoint}) |
| initialConnection = false |
| } else { |
| logger.Debugw(ctx, "endpoint-reconnection", log.Fields{"endpoint": c.apiEndPoint}) |
| // Trigger any callback on a restart |
| go func() { |
| err := c.onRestart(log.WithSpanFromContext(context.Background(), ctx), c.apiEndPoint) |
| if err != nil { |
| logger.Errorw(ctx, "unable-to-restart-endpoint", log.Fields{"error": err, "endpoint": c.apiEndPoint}) |
| } |
| }() |
| } |
| } |
| c.stateLock.Unlock() |
| |
| case eventDisconnected: |
| if p != nil { |
| p.UpdateStatus(ctx, c.apiEndPoint, probe.ServiceStatusNotReady) |
| } |
| c.stateLock.RLock() |
| logger.Debugw(ctx, "endpoint-disconnected", log.Fields{"endpoint": c.apiEndPoint, "curr-state": c.state}) |
| c.stateLock.RUnlock() |
| |
| // Try to connect again |
| c.events <- eventConnecting |
| |
| case eventStopped: |
| logger.Debugw(ctx, "endPoint-stopped", log.Fields{"adapter": c.apiEndPoint}) |
| go func() { |
| if err := c.closeConnection(ctx, p); err != nil { |
| logger.Errorw(ctx, "endpoint-closing-connection-failed", log.Fields{"endpoint": c.apiEndPoint, "error": err}) |
| } |
| }() |
| break loop |
| case eventError: |
| logger.Errorw(ctx, "endpoint-error-event", log.Fields{"endpoint": c.apiEndPoint}) |
| default: |
| logger.Errorw(ctx, "endpoint-unknown-event", log.Fields{"endpoint": c.apiEndPoint, "error": event}) |
| } |
| } |
| } |
| logger.Infow(ctx, "endpoint-stopped", log.Fields{"endpoint": c.apiEndPoint}) |
| } |
| |
| func (c *Client) connectToEndpoint(ctx context.Context, handler SetAndTestServiceHandler, p *probe.Probe) error { |
| if p != nil { |
| p.UpdateStatus(ctx, c.apiEndPoint, probe.ServiceStatusPreparing) |
| } |
| |
| c.connectionLock.Lock() |
| defer c.connectionLock.Unlock() |
| |
| if c.connection != nil { |
| _ = c.connection.Close() |
| c.connection = nil |
| } |
| |
| c.service = nil |
| |
| // Use Interceptors to: |
| // 1. automatically inject |
| // 2. publish Open Tracing Spans by this GRPC Client |
| // 3. detect connection failure on client calls such that the reconnection process can begin |
| conn, err := grpc.Dial(c.apiEndPoint, |
| grpc.WithInsecure(), |
| grpc.WithStreamInterceptor(grpc_middleware.ChainStreamClient( |
| grpc_opentracing.StreamClientInterceptor(grpc_opentracing.WithTracer(log.ActiveTracerProxy{})), |
| )), |
| grpc.WithUnaryInterceptor(grpc_middleware.ChainUnaryClient( |
| grpc_opentracing.UnaryClientInterceptor(grpc_opentracing.WithTracer(log.ActiveTracerProxy{})), |
| )), |
| grpc.WithUnaryInterceptor(c.clientInterceptor), |
| // Set keealive parameter - use default grpc values |
| grpc.WithKeepaliveParams(keepalive.ClientParameters{ |
| Time: c.monitorInterval, |
| Timeout: c.backoffMaxInterval, |
| PermitWithoutStream: true, |
| }), |
| ) |
| |
| if err == nil { |
| subCtx, cancel := context.WithTimeout(ctx, c.backoffMaxInterval) |
| defer cancel() |
| svc := handler(subCtx, conn) |
| if svc != nil { |
| c.connection = conn |
| c.service = svc |
| if p != nil { |
| p.UpdateStatus(ctx, c.apiEndPoint, probe.ServiceStatusRunning) |
| } |
| logger.Infow(ctx, "connected-to-endpoint", log.Fields{"endpoint": c.apiEndPoint}) |
| c.events <- eventConnected |
| return nil |
| } |
| } |
| logger.Warnw(ctx, "Failed to connect to endpoint", |
| log.Fields{ |
| "endpoint": c.apiEndPoint, |
| "error": err, |
| }) |
| |
| if p != nil { |
| p.UpdateStatus(ctx, c.apiEndPoint, probe.ServiceStatusFailed) |
| } |
| return fmt.Errorf("no connection to endpoint %s", c.apiEndPoint) |
| } |
| |
| func (c *Client) closeConnection(ctx context.Context, p *probe.Probe) error { |
| if p != nil { |
| p.UpdateStatus(ctx, c.apiEndPoint, probe.ServiceStatusStopped) |
| } |
| |
| c.connectionLock.Lock() |
| defer c.connectionLock.Unlock() |
| |
| if c.connection != nil { |
| err := c.connection.Close() |
| c.connection = nil |
| return err |
| } |
| |
| return nil |
| } |
| |
| func (c *Client) Stop(ctx context.Context) { |
| if !c.done { |
| c.events <- eventStopped |
| close(c.events) |
| c.done = true |
| } |
| } |
| |
| // SetService is used for testing only |
| func (c *Client) SetService(srv interface{}) { |
| c.connectionLock.Lock() |
| defer c.connectionLock.Unlock() |
| c.service = srv |
| } |
| |
| func (c *Client) SubscribeForLiveness(callback func(timestamp time.Time)) { |
| c.livenessCallback = callback |
| } |