blob: 368391e4814174f5c57bb9d863724a5e9d9f7d5e [file] [log] [blame]
/*
* 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 kafka
import (
"context"
"errors"
"fmt"
"reflect"
"strings"
"sync"
"time"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"
"github.com/golang/protobuf/proto"
"github.com/golang/protobuf/ptypes"
"github.com/golang/protobuf/ptypes/any"
"github.com/google/uuid"
"github.com/opencord/voltha-lib-go/v3/pkg/log"
ic "github.com/opencord/voltha-protos/v3/go/inter_container"
)
const (
DefaultMaxRetries = 3
DefaultRequestTimeout = 60000 // 60000 milliseconds - to handle a wider latency range
)
const (
TransactionKey = "transactionID"
FromTopic = "fromTopic"
)
var ErrorTransactionNotAcquired = errors.New("transaction-not-acquired")
var ErrorTransactionInvalidId = errors.New("transaction-invalid-id")
// requestHandlerChannel represents an interface associated with a channel. Whenever, an event is
// obtained from that channel, this interface is invoked. This is used to handle
// async requests into the Core via the kafka messaging bus
type requestHandlerChannel struct {
requesthandlerInterface interface{}
ch <-chan *ic.InterContainerMessage
}
// transactionChannel represents a combination of a topic and a channel onto which a response received
// on the kafka bus will be sent to
type transactionChannel struct {
topic *Topic
ch chan *ic.InterContainerMessage
}
type InterContainerProxy interface {
Start(ctx context.Context) error
Stop(ctx context.Context)
GetDefaultTopic() *Topic
InvokeRPC(ctx context.Context, rpc string, toTopic *Topic, replyToTopic *Topic, waitForResponse bool, key string, kvArgs ...*KVArg) (bool, *any.Any)
InvokeAsyncRPC(ctx context.Context, rpc string, toTopic *Topic, replyToTopic *Topic, waitForResponse bool, key string, kvArgs ...*KVArg) chan *RpcResponse
SubscribeWithRequestHandlerInterface(ctx context.Context, topic Topic, handler interface{}) error
SubscribeWithDefaultRequestHandler(ctx context.Context, topic Topic, initialOffset int64) error
UnSubscribeFromRequestHandler(ctx context.Context, topic Topic) error
DeleteTopic(ctx context.Context, topic Topic) error
EnableLivenessChannel(ctx context.Context, enable bool) chan bool
SendLiveness(ctx context.Context) error
}
// interContainerProxy represents the messaging proxy
type interContainerProxy struct {
kafkaAddress string
defaultTopic *Topic
defaultRequestHandlerInterface interface{}
kafkaClient Client
doneCh chan struct{}
doneOnce sync.Once
// This map is used to map a topic to an interface and channel. When a request is received
// on that channel (registered to the topic) then that interface is invoked.
topicToRequestHandlerChannelMap map[string]*requestHandlerChannel
lockTopicRequestHandlerChannelMap sync.RWMutex
// This map is used to map a channel to a response topic. This channel handles all responses on that
// channel for that topic and forward them to the appropriate consumers channel, using the
// transactionIdToChannelMap.
topicToResponseChannelMap map[string]<-chan *ic.InterContainerMessage
lockTopicResponseChannelMap sync.RWMutex
// This map is used to map a transaction to a consumers channel. This is used whenever a request has been
// sent out and we are waiting for a response.
transactionIdToChannelMap map[string]*transactionChannel
lockTransactionIdToChannelMap sync.RWMutex
}
type InterContainerProxyOption func(*interContainerProxy)
func InterContainerAddress(address string) InterContainerProxyOption {
return func(args *interContainerProxy) {
args.kafkaAddress = address
}
}
func DefaultTopic(topic *Topic) InterContainerProxyOption {
return func(args *interContainerProxy) {
args.defaultTopic = topic
}
}
func RequestHandlerInterface(handler interface{}) InterContainerProxyOption {
return func(args *interContainerProxy) {
args.defaultRequestHandlerInterface = handler
}
}
func MsgClient(client Client) InterContainerProxyOption {
return func(args *interContainerProxy) {
args.kafkaClient = client
}
}
func newInterContainerProxy(opts ...InterContainerProxyOption) *interContainerProxy {
proxy := &interContainerProxy{
kafkaAddress: DefaultKafkaAddress,
doneCh: make(chan struct{}),
}
for _, option := range opts {
option(proxy)
}
return proxy
}
func NewInterContainerProxy(opts ...InterContainerProxyOption) InterContainerProxy {
return newInterContainerProxy(opts...)
}
func (kp *interContainerProxy) Start(ctx context.Context) error {
logger.Info(ctx, "Starting-Proxy")
// Kafka MsgClient should already have been created. If not, output fatal error
if kp.kafkaClient == nil {
logger.Fatal(ctx, "kafka-client-not-set")
}
// Start the kafka client
if err := kp.kafkaClient.Start(ctx); err != nil {
logger.Errorw(ctx, "Cannot-create-kafka-proxy", log.Fields{"error": err})
return err
}
// Create the topic to response channel map
kp.topicToResponseChannelMap = make(map[string]<-chan *ic.InterContainerMessage)
//
// Create the transactionId to Channel Map
kp.transactionIdToChannelMap = make(map[string]*transactionChannel)
// Create the topic to request channel map
kp.topicToRequestHandlerChannelMap = make(map[string]*requestHandlerChannel)
return nil
}
func (kp *interContainerProxy) Stop(ctx context.Context) {
logger.Info(ctx, "stopping-intercontainer-proxy")
kp.doneOnce.Do(func() { close(kp.doneCh) })
// TODO : Perform cleanup
kp.kafkaClient.Stop(ctx)
err := kp.deleteAllTopicRequestHandlerChannelMap(ctx)
if err != nil {
logger.Errorw(ctx, "failed-delete-all-topic-request-handler-channel-map", log.Fields{"error": err})
}
err = kp.deleteAllTopicResponseChannelMap(ctx)
if err != nil {
logger.Errorw(ctx, "failed-delete-all-topic-response-channel-map", log.Fields{"error": err})
}
kp.deleteAllTransactionIdToChannelMap(ctx)
}
func (kp *interContainerProxy) GetDefaultTopic() *Topic {
return kp.defaultTopic
}
// InvokeAsyncRPC is used to make an RPC request asynchronously
func (kp *interContainerProxy) InvokeAsyncRPC(ctx context.Context, rpc string, toTopic *Topic, replyToTopic *Topic,
waitForResponse bool, key string, kvArgs ...*KVArg) chan *RpcResponse {
logger.Debugw(ctx, "InvokeAsyncRPC", log.Fields{"rpc": rpc, "key": key})
// If a replyToTopic is provided then we use it, otherwise just use the default toTopic. The replyToTopic is
// typically the device ID.
responseTopic := replyToTopic
if responseTopic == nil {
responseTopic = kp.GetDefaultTopic()
}
chnl := make(chan *RpcResponse)
go func() {
// once we're done,
// close the response channel
defer close(chnl)
var err error
var protoRequest *ic.InterContainerMessage
// Encode the request
protoRequest, err = encodeRequest(ctx, rpc, toTopic, responseTopic, key, kvArgs...)
if err != nil {
logger.Warnw(ctx, "cannot-format-request", log.Fields{"rpc": rpc, "error": err})
chnl <- NewResponse(RpcFormattingError, err, nil)
return
}
// Subscribe for response, if needed, before sending request
var ch <-chan *ic.InterContainerMessage
if ch, err = kp.subscribeForResponse(ctx, *responseTopic, protoRequest.Header.Id); err != nil {
logger.Errorw(ctx, "failed-to-subscribe-for-response", log.Fields{"error": err, "toTopic": toTopic.Name})
chnl <- NewResponse(RpcTransportError, err, nil)
return
}
// Send request - if the topic is formatted with a device Id then we will send the request using a
// specific key, hence ensuring a single partition is used to publish the request. This ensures that the
// subscriber on that topic will receive the request in the order it was sent. The key used is the deviceId.
logger.Debugw(ctx, "sending-msg", log.Fields{"rpc": rpc, "toTopic": toTopic, "replyTopic": responseTopic, "key": key, "xId": protoRequest.Header.Id})
// if the message is not sent on kafka publish an event an close the channel
if err = kp.kafkaClient.Send(ctx, protoRequest, toTopic, key); err != nil {
chnl <- NewResponse(RpcTransportError, err, nil)
return
}
// if the client is not waiting for a response send the ack and close the channel
chnl <- NewResponse(RpcSent, nil, nil)
if !waitForResponse {
return
}
defer func() {
// Remove the subscription for a response on return
if err := kp.unSubscribeForResponse(ctx, protoRequest.Header.Id); err != nil {
logger.Warnw(ctx, "invoke-async-rpc-unsubscriber-for-response-failed", log.Fields{"err": err})
}
}()
// Wait for response as well as timeout or cancellation
select {
case msg, ok := <-ch:
if !ok {
logger.Warnw(ctx, "channel-closed", log.Fields{"rpc": rpc, "replyTopic": replyToTopic.Name})
chnl <- NewResponse(RpcTransportError, status.Error(codes.Aborted, "channel closed"), nil)
}
logger.Debugw(ctx, "received-response", log.Fields{"rpc": rpc, "msgHeader": msg.Header})
if responseBody, err := decodeResponse(ctx, msg); err != nil {
chnl <- NewResponse(RpcReply, err, nil)
} else {
if responseBody.Success {
chnl <- NewResponse(RpcReply, nil, responseBody.Result)
} else {
// response body contains an error
unpackErr := &ic.Error{}
if err := ptypes.UnmarshalAny(responseBody.Result, unpackErr); err != nil {
chnl <- NewResponse(RpcReply, err, nil)
} else {
chnl <- NewResponse(RpcReply, status.Error(codes.Internal, unpackErr.Reason), nil)
}
}
}
case <-ctx.Done():
logger.Errorw(ctx, "context-cancelled", log.Fields{"rpc": rpc, "ctx": ctx.Err()})
err := status.Error(codes.DeadlineExceeded, ctx.Err().Error())
chnl <- NewResponse(RpcTimeout, err, nil)
case <-kp.doneCh:
chnl <- NewResponse(RpcSystemClosing, nil, nil)
logger.Warnw(ctx, "received-exit-signal", log.Fields{"toTopic": toTopic.Name, "rpc": rpc})
}
}()
return chnl
}
// InvokeRPC is used to send a request to a given topic
func (kp *interContainerProxy) InvokeRPC(ctx context.Context, rpc string, toTopic *Topic, replyToTopic *Topic,
waitForResponse bool, key string, kvArgs ...*KVArg) (bool, *any.Any) {
// If a replyToTopic is provided then we use it, otherwise just use the default toTopic. The replyToTopic is
// typically the device ID.
responseTopic := replyToTopic
if responseTopic == nil {
responseTopic = kp.defaultTopic
}
// Encode the request
protoRequest, err := encodeRequest(ctx, rpc, toTopic, responseTopic, key, kvArgs...)
if err != nil {
logger.Warnw(ctx, "cannot-format-request", log.Fields{"rpc": rpc, "error": err})
return false, nil
}
// Subscribe for response, if needed, before sending request
var ch <-chan *ic.InterContainerMessage
if waitForResponse {
var err error
if ch, err = kp.subscribeForResponse(ctx, *responseTopic, protoRequest.Header.Id); err != nil {
logger.Errorw(ctx, "failed-to-subscribe-for-response", log.Fields{"error": err, "toTopic": toTopic.Name})
}
}
// Send request - if the topic is formatted with a device Id then we will send the request using a
// specific key, hence ensuring a single partition is used to publish the request. This ensures that the
// subscriber on that topic will receive the request in the order it was sent. The key used is the deviceId.
//key := GetDeviceIdFromTopic(*toTopic)
logger.Debugw(ctx, "sending-msg", log.Fields{"rpc": rpc, "toTopic": toTopic, "replyTopic": responseTopic, "key": key, "xId": protoRequest.Header.Id})
go func() {
if err := kp.kafkaClient.Send(ctx, protoRequest, toTopic, key); err != nil {
logger.Errorw(ctx, "send-failed", log.Fields{
"topic": toTopic,
"key": key,
"error": err})
}
}()
if waitForResponse {
// Create a child context based on the parent context, if any
var cancel context.CancelFunc
childCtx := context.Background()
if ctx == nil {
ctx, cancel = context.WithTimeout(context.Background(), DefaultRequestTimeout*time.Millisecond)
} else {
childCtx, cancel = context.WithTimeout(ctx, DefaultRequestTimeout*time.Millisecond)
}
defer cancel()
// Wait for response as well as timeout or cancellation
// Remove the subscription for a response on return
defer func() {
if err := kp.unSubscribeForResponse(ctx, protoRequest.Header.Id); err != nil {
logger.Errorw(ctx, "response-unsubscribe-failed", log.Fields{
"id": protoRequest.Header.Id,
"error": err})
}
}()
select {
case msg, ok := <-ch:
if !ok {
logger.Warnw(ctx, "channel-closed", log.Fields{"rpc": rpc, "replyTopic": replyToTopic.Name})
protoError := &ic.Error{Reason: "channel-closed"}
var marshalledArg *any.Any
if marshalledArg, err = ptypes.MarshalAny(protoError); err != nil {
return false, nil // Should never happen
}
return false, marshalledArg
}
logger.Debugw(ctx, "received-response", log.Fields{"rpc": rpc, "msgHeader": msg.Header})
var responseBody *ic.InterContainerResponseBody
var err error
if responseBody, err = decodeResponse(ctx, msg); err != nil {
logger.Errorw(ctx, "decode-response-error", log.Fields{"error": err})
// FIXME we should return something
}
return responseBody.Success, responseBody.Result
case <-ctx.Done():
logger.Debugw(ctx, "context-cancelled", log.Fields{"rpc": rpc, "ctx": ctx.Err()})
// pack the error as proto any type
protoError := &ic.Error{Reason: ctx.Err().Error(), Code: ic.ErrorCode_DEADLINE_EXCEEDED}
var marshalledArg *any.Any
if marshalledArg, err = ptypes.MarshalAny(protoError); err != nil {
return false, nil // Should never happen
}
return false, marshalledArg
case <-childCtx.Done():
logger.Debugw(ctx, "context-cancelled", log.Fields{"rpc": rpc, "ctx": childCtx.Err()})
// pack the error as proto any type
protoError := &ic.Error{Reason: childCtx.Err().Error(), Code: ic.ErrorCode_DEADLINE_EXCEEDED}
var marshalledArg *any.Any
if marshalledArg, err = ptypes.MarshalAny(protoError); err != nil {
return false, nil // Should never happen
}
return false, marshalledArg
case <-kp.doneCh:
logger.Infow(ctx, "received-exit-signal", log.Fields{"toTopic": toTopic.Name, "rpc": rpc})
return true, nil
}
}
return true, nil
}
// SubscribeWithRequestHandlerInterface allows a caller to assign a target object to be invoked automatically
// when a message is received on a given topic
func (kp *interContainerProxy) SubscribeWithRequestHandlerInterface(ctx context.Context, topic Topic, handler interface{}) error {
// Subscribe to receive messages for that topic
var ch <-chan *ic.InterContainerMessage
var err error
if ch, err = kp.kafkaClient.Subscribe(ctx, &topic); err != nil {
//if ch, err = kp.Subscribe(topic); err != nil {
logger.Errorw(ctx, "failed-to-subscribe", log.Fields{"error": err, "topic": topic.Name})
return err
}
kp.defaultRequestHandlerInterface = handler
kp.addToTopicRequestHandlerChannelMap(topic.Name, &requestHandlerChannel{requesthandlerInterface: handler, ch: ch})
// Launch a go routine to receive and process kafka messages
go kp.waitForMessages(ctx, ch, topic, handler)
return nil
}
// SubscribeWithDefaultRequestHandler allows a caller to add a topic to an existing target object to be invoked automatically
// when a message is received on a given topic. So far there is only 1 target registered per microservice
func (kp *interContainerProxy) SubscribeWithDefaultRequestHandler(ctx context.Context, topic Topic, initialOffset int64) error {
// Subscribe to receive messages for that topic
var ch <-chan *ic.InterContainerMessage
var err error
if ch, err = kp.kafkaClient.Subscribe(ctx, &topic, &KVArg{Key: Offset, Value: initialOffset}); err != nil {
logger.Errorw(ctx, "failed-to-subscribe", log.Fields{"error": err, "topic": topic.Name})
return err
}
kp.addToTopicRequestHandlerChannelMap(topic.Name, &requestHandlerChannel{requesthandlerInterface: kp.defaultRequestHandlerInterface, ch: ch})
// Launch a go routine to receive and process kafka messages
go kp.waitForMessages(ctx, ch, topic, kp.defaultRequestHandlerInterface)
return nil
}
func (kp *interContainerProxy) UnSubscribeFromRequestHandler(ctx context.Context, topic Topic) error {
return kp.deleteFromTopicRequestHandlerChannelMap(ctx, topic.Name)
}
func (kp *interContainerProxy) deleteFromTopicResponseChannelMap(ctx context.Context, topic string) error {
kp.lockTopicResponseChannelMap.Lock()
defer kp.lockTopicResponseChannelMap.Unlock()
if _, exist := kp.topicToResponseChannelMap[topic]; exist {
// Unsubscribe to this topic first - this will close the subscribed channel
var err error
if err = kp.kafkaClient.UnSubscribe(ctx, &Topic{Name: topic}, kp.topicToResponseChannelMap[topic]); err != nil {
logger.Errorw(ctx, "unsubscribing-error", log.Fields{"topic": topic})
}
delete(kp.topicToResponseChannelMap, topic)
return err
} else {
return fmt.Errorf("%s-Topic-not-found", topic)
}
}
// nolint: unused
func (kp *interContainerProxy) deleteAllTopicResponseChannelMap(ctx context.Context) error {
logger.Debug(ctx, "delete-all-topic-response-channel")
kp.lockTopicResponseChannelMap.Lock()
defer kp.lockTopicResponseChannelMap.Unlock()
var unsubscribeFailTopics []string
for topic := range kp.topicToResponseChannelMap {
// Unsubscribe to this topic first - this will close the subscribed channel
if err := kp.kafkaClient.UnSubscribe(ctx, &Topic{Name: topic}, kp.topicToResponseChannelMap[topic]); err != nil {
unsubscribeFailTopics = append(unsubscribeFailTopics, topic)
logger.Errorw(ctx, "unsubscribing-error", log.Fields{"topic": topic, "error": err})
// Do not return. Continue to try to unsubscribe to other topics.
} else {
// Only delete from channel map if successfully unsubscribed.
delete(kp.topicToResponseChannelMap, topic)
}
}
if len(unsubscribeFailTopics) > 0 {
return fmt.Errorf("unsubscribe-errors: %v", unsubscribeFailTopics)
}
return nil
}
func (kp *interContainerProxy) addToTopicRequestHandlerChannelMap(topic string, arg *requestHandlerChannel) {
kp.lockTopicRequestHandlerChannelMap.Lock()
defer kp.lockTopicRequestHandlerChannelMap.Unlock()
if _, exist := kp.topicToRequestHandlerChannelMap[topic]; !exist {
kp.topicToRequestHandlerChannelMap[topic] = arg
}
}
func (kp *interContainerProxy) deleteFromTopicRequestHandlerChannelMap(ctx context.Context, topic string) error {
kp.lockTopicRequestHandlerChannelMap.Lock()
defer kp.lockTopicRequestHandlerChannelMap.Unlock()
if _, exist := kp.topicToRequestHandlerChannelMap[topic]; exist {
// Close the kafka client client first by unsubscribing to this topic
if err := kp.kafkaClient.UnSubscribe(ctx, &Topic{Name: topic}, kp.topicToRequestHandlerChannelMap[topic].ch); err != nil {
return err
}
delete(kp.topicToRequestHandlerChannelMap, topic)
return nil
} else {
return fmt.Errorf("%s-Topic-not-found", topic)
}
}
// nolint: unused
func (kp *interContainerProxy) deleteAllTopicRequestHandlerChannelMap(ctx context.Context) error {
logger.Debug(ctx, "delete-all-topic-request-channel")
kp.lockTopicRequestHandlerChannelMap.Lock()
defer kp.lockTopicRequestHandlerChannelMap.Unlock()
var unsubscribeFailTopics []string
for topic := range kp.topicToRequestHandlerChannelMap {
// Close the kafka client client first by unsubscribing to this topic
if err := kp.kafkaClient.UnSubscribe(ctx, &Topic{Name: topic}, kp.topicToRequestHandlerChannelMap[topic].ch); err != nil {
unsubscribeFailTopics = append(unsubscribeFailTopics, topic)
logger.Errorw(ctx, "unsubscribing-error", log.Fields{"topic": topic, "error": err})
// Do not return. Continue to try to unsubscribe to other topics.
} else {
// Only delete from channel map if successfully unsubscribed.
delete(kp.topicToRequestHandlerChannelMap, topic)
}
}
if len(unsubscribeFailTopics) > 0 {
return fmt.Errorf("unsubscribe-errors: %v", unsubscribeFailTopics)
}
return nil
}
func (kp *interContainerProxy) addToTransactionIdToChannelMap(id string, topic *Topic, arg chan *ic.InterContainerMessage) {
kp.lockTransactionIdToChannelMap.Lock()
defer kp.lockTransactionIdToChannelMap.Unlock()
if _, exist := kp.transactionIdToChannelMap[id]; !exist {
kp.transactionIdToChannelMap[id] = &transactionChannel{topic: topic, ch: arg}
}
}
func (kp *interContainerProxy) deleteFromTransactionIdToChannelMap(id string) {
kp.lockTransactionIdToChannelMap.Lock()
defer kp.lockTransactionIdToChannelMap.Unlock()
if transChannel, exist := kp.transactionIdToChannelMap[id]; exist {
// Close the channel first
close(transChannel.ch)
delete(kp.transactionIdToChannelMap, id)
}
}
func (kp *interContainerProxy) deleteTopicTransactionIdToChannelMap(id string) {
kp.lockTransactionIdToChannelMap.Lock()
defer kp.lockTransactionIdToChannelMap.Unlock()
for key, value := range kp.transactionIdToChannelMap {
if value.topic.Name == id {
close(value.ch)
delete(kp.transactionIdToChannelMap, key)
}
}
}
// nolint: unused
func (kp *interContainerProxy) deleteAllTransactionIdToChannelMap(ctx context.Context) {
logger.Debug(ctx, "delete-all-transaction-id-channel-map")
kp.lockTransactionIdToChannelMap.Lock()
defer kp.lockTransactionIdToChannelMap.Unlock()
for key, value := range kp.transactionIdToChannelMap {
close(value.ch)
delete(kp.transactionIdToChannelMap, key)
}
}
func (kp *interContainerProxy) DeleteTopic(ctx context.Context, topic Topic) error {
// If we have any consumers on that topic we need to close them
if err := kp.deleteFromTopicResponseChannelMap(ctx, topic.Name); err != nil {
logger.Errorw(ctx, "delete-from-topic-responsechannelmap-failed", log.Fields{"error": err})
}
if err := kp.deleteFromTopicRequestHandlerChannelMap(ctx, topic.Name); err != nil {
logger.Errorw(ctx, "delete-from-topic-requesthandlerchannelmap-failed", log.Fields{"error": err})
}
kp.deleteTopicTransactionIdToChannelMap(topic.Name)
return kp.kafkaClient.DeleteTopic(ctx, &topic)
}
func encodeReturnedValue(ctx context.Context, returnedVal interface{}) (*any.Any, error) {
// Encode the response argument - needs to be a proto message
if returnedVal == nil {
return nil, nil
}
protoValue, ok := returnedVal.(proto.Message)
if !ok {
logger.Warnw(ctx, "response-value-not-proto-message", log.Fields{"error": ok, "returnVal": returnedVal})
err := errors.New("response-value-not-proto-message")
return nil, err
}
// Marshal the returned value, if any
var marshalledReturnedVal *any.Any
var err error
if marshalledReturnedVal, err = ptypes.MarshalAny(protoValue); err != nil {
logger.Warnw(ctx, "cannot-marshal-returned-val", log.Fields{"error": err})
return nil, err
}
return marshalledReturnedVal, nil
}
func encodeDefaultFailedResponse(ctx context.Context, request *ic.InterContainerMessage) *ic.InterContainerMessage {
responseHeader := &ic.Header{
Id: request.Header.Id,
Type: ic.MessageType_RESPONSE,
FromTopic: request.Header.ToTopic,
ToTopic: request.Header.FromTopic,
Timestamp: ptypes.TimestampNow(),
}
responseBody := &ic.InterContainerResponseBody{
Success: false,
Result: nil,
}
var marshalledResponseBody *any.Any
var err error
// Error should never happen here
if marshalledResponseBody, err = ptypes.MarshalAny(responseBody); err != nil {
logger.Warnw(ctx, "cannot-marshal-failed-response-body", log.Fields{"error": err})
}
return &ic.InterContainerMessage{
Header: responseHeader,
Body: marshalledResponseBody,
}
}
//formatRequest formats a request to send over kafka and returns an InterContainerMessage message on success
//or an error on failure
func encodeResponse(ctx context.Context, request *ic.InterContainerMessage, success bool, returnedValues ...interface{}) (*ic.InterContainerMessage, error) {
//logger.Debugw(ctx, "encodeResponse", log.Fields{"success": success, "returnedValues": returnedValues})
responseHeader := &ic.Header{
Id: request.Header.Id,
Type: ic.MessageType_RESPONSE,
FromTopic: request.Header.ToTopic,
ToTopic: request.Header.FromTopic,
KeyTopic: request.Header.KeyTopic,
Timestamp: ptypes.TimestampNow(),
}
// Go over all returned values
var marshalledReturnedVal *any.Any
var err error
// for now we support only 1 returned value - (excluding the error)
if len(returnedValues) > 0 {
if marshalledReturnedVal, err = encodeReturnedValue(ctx, returnedValues[0]); err != nil {
logger.Warnw(ctx, "cannot-marshal-response-body", log.Fields{"error": err})
}
}
responseBody := &ic.InterContainerResponseBody{
Success: success,
Result: marshalledReturnedVal,
}
// Marshal the response body
var marshalledResponseBody *any.Any
if marshalledResponseBody, err = ptypes.MarshalAny(responseBody); err != nil {
logger.Warnw(ctx, "cannot-marshal-response-body", log.Fields{"error": err})
return nil, err
}
return &ic.InterContainerMessage{
Header: responseHeader,
Body: marshalledResponseBody,
}, nil
}
func CallFuncByName(ctx context.Context, myClass interface{}, funcName string, params ...interface{}) (out []reflect.Value, err error) {
myClassValue := reflect.ValueOf(myClass)
// Capitalize the first letter in the funcName to workaround the first capital letters required to
// invoke a function from a different package
funcName = strings.Title(funcName)
m := myClassValue.MethodByName(funcName)
if !m.IsValid() {
return make([]reflect.Value, 0), fmt.Errorf("method-not-found \"%s\"", funcName)
}
in := make([]reflect.Value, len(params)+1)
in[0] = reflect.ValueOf(ctx)
for i, param := range params {
in[i+1] = reflect.ValueOf(param)
}
out = m.Call(in)
return
}
func (kp *interContainerProxy) addTransactionId(ctx context.Context, transactionId string, currentArgs []*ic.Argument) []*ic.Argument {
arg := &KVArg{
Key: TransactionKey,
Value: &ic.StrType{Val: transactionId},
}
var marshalledArg *any.Any
var err error
if marshalledArg, err = ptypes.MarshalAny(&ic.StrType{Val: transactionId}); err != nil {
logger.Warnw(ctx, "cannot-add-transactionId", log.Fields{"error": err})
return currentArgs
}
protoArg := &ic.Argument{
Key: arg.Key,
Value: marshalledArg,
}
return append(currentArgs, protoArg)
}
func (kp *interContainerProxy) addFromTopic(ctx context.Context, fromTopic string, currentArgs []*ic.Argument) []*ic.Argument {
var marshalledArg *any.Any
var err error
if marshalledArg, err = ptypes.MarshalAny(&ic.StrType{Val: fromTopic}); err != nil {
logger.Warnw(ctx, "cannot-add-transactionId", log.Fields{"error": err})
return currentArgs
}
protoArg := &ic.Argument{
Key: FromTopic,
Value: marshalledArg,
}
return append(currentArgs, protoArg)
}
func (kp *interContainerProxy) handleMessage(ctx context.Context, msg *ic.InterContainerMessage, targetInterface interface{}) {
// First extract the header to know whether this is a request - responses are handled by a different handler
if msg.Header.Type == ic.MessageType_REQUEST {
var out []reflect.Value
var err error
// Get the request body
requestBody := &ic.InterContainerRequestBody{}
if err = ptypes.UnmarshalAny(msg.Body, requestBody); err != nil {
logger.Warnw(ctx, "cannot-unmarshal-request", log.Fields{"error": err})
} else {
logger.Debugw(ctx, "received-request", log.Fields{"rpc": requestBody.Rpc, "header": msg.Header})
// let the callee unpack the arguments as its the only one that knows the real proto type
// Augment the requestBody with the message Id as it will be used in scenarios where cores
// are set in pairs and competing
requestBody.Args = kp.addTransactionId(ctx, msg.Header.Id, requestBody.Args)
// Augment the requestBody with the From topic name as it will be used in scenarios where a container
// needs to send an unsollicited message to the currently requested container
requestBody.Args = kp.addFromTopic(ctx, msg.Header.FromTopic, requestBody.Args)
out, err = CallFuncByName(ctx, targetInterface, requestBody.Rpc, requestBody.Args)
if err != nil {
logger.Warn(ctx, err)
}
}
// Response required?
if requestBody.ResponseRequired {
// If we already have an error before then just return that
var returnError *ic.Error
var returnedValues []interface{}
var success bool
if err != nil {
returnError = &ic.Error{Reason: err.Error()}
returnedValues = make([]interface{}, 1)
returnedValues[0] = returnError
} else {
returnedValues = make([]interface{}, 0)
// Check for errors first
lastIndex := len(out) - 1
if out[lastIndex].Interface() != nil { // Error
if retError, ok := out[lastIndex].Interface().(error); ok {
if retError.Error() == ErrorTransactionNotAcquired.Error() {
logger.Debugw(ctx, "Ignoring request", log.Fields{"error": retError, "txId": msg.Header.Id})
return // Ignore - process is in competing mode and ignored transaction
}
returnError = &ic.Error{Reason: retError.Error()}
returnedValues = append(returnedValues, returnError)
} else { // Should never happen
returnError = &ic.Error{Reason: "incorrect-error-returns"}
returnedValues = append(returnedValues, returnError)
}
} else if len(out) == 2 && reflect.ValueOf(out[0].Interface()).IsValid() && reflect.ValueOf(out[0].Interface()).IsNil() {
logger.Warnw(ctx, "Unexpected response of (nil,nil)", log.Fields{"txId": msg.Header.Id})
return // Ignore - should not happen
} else { // Non-error case
success = true
for idx, val := range out {
//logger.Debugw(ctx, "returned-api-response-loop", log.Fields{"idx": idx, "val": val.Interface()})
if idx != lastIndex {
returnedValues = append(returnedValues, val.Interface())
}
}
}
}
var icm *ic.InterContainerMessage
if icm, err = encodeResponse(ctx, msg, success, returnedValues...); err != nil {
logger.Warnw(ctx, "error-encoding-response-returning-failure-result", log.Fields{"error": err})
icm = encodeDefaultFailedResponse(ctx, msg)
}
// To preserve ordering of messages, all messages to a given topic are sent to the same partition
// by providing a message key. The key is encoded in the topic name. If the deviceId is not
// present then the key will be empty, hence all messages for a given topic will be sent to all
// partitions.
replyTopic := &Topic{Name: msg.Header.FromTopic}
key := msg.Header.KeyTopic
logger.Debugw(ctx, "sending-response-to-kafka", log.Fields{"rpc": requestBody.Rpc, "header": icm.Header, "key": key})
// TODO: handle error response.
go func() {
if err := kp.kafkaClient.Send(ctx, icm, replyTopic, key); err != nil {
logger.Errorw(ctx, "send-reply-failed", log.Fields{
"topic": replyTopic,
"key": key,
"error": err})
}
}()
}
} else if msg.Header.Type == ic.MessageType_RESPONSE {
logger.Debugw(ctx, "response-received", log.Fields{"msg-header": msg.Header})
go kp.dispatchResponse(ctx, msg)
} else {
logger.Warnw(ctx, "unsupported-message-received", log.Fields{"msg-header": msg.Header})
}
}
func (kp *interContainerProxy) waitForMessages(ctx context.Context, ch <-chan *ic.InterContainerMessage, topic Topic, targetInterface interface{}) {
// Wait for messages
for msg := range ch {
//logger.Debugw(ctx, "request-received", log.Fields{"msg": msg, "topic": topic.Name, "target": targetInterface})
go kp.handleMessage(context.Background(), msg, targetInterface)
}
}
func (kp *interContainerProxy) dispatchResponse(ctx context.Context, msg *ic.InterContainerMessage) {
kp.lockTransactionIdToChannelMap.RLock()
defer kp.lockTransactionIdToChannelMap.RUnlock()
if _, exist := kp.transactionIdToChannelMap[msg.Header.Id]; !exist {
logger.Debugw(ctx, "no-waiting-channel", log.Fields{"transaction": msg.Header.Id})
return
}
kp.transactionIdToChannelMap[msg.Header.Id].ch <- msg
}
// subscribeForResponse allows a caller to subscribe to a given topic when waiting for a response.
// This method is built to prevent all subscribers to receive all messages as is the case of the Subscribe
// API. There is one response channel waiting for kafka messages before dispatching the message to the
// corresponding waiting channel
func (kp *interContainerProxy) subscribeForResponse(ctx context.Context, topic Topic, trnsId string) (chan *ic.InterContainerMessage, error) {
logger.Debugw(ctx, "subscribeForResponse", log.Fields{"topic": topic.Name, "trnsid": trnsId})
// Create a specific channel for this consumers. We cannot use the channel from the kafkaclient as it will
// broadcast any message for this topic to all channels waiting on it.
// Set channel size to 1 to prevent deadlock, see VOL-2708
ch := make(chan *ic.InterContainerMessage, 1)
kp.addToTransactionIdToChannelMap(trnsId, &topic, ch)
return ch, nil
}
func (kp *interContainerProxy) unSubscribeForResponse(ctx context.Context, trnsId string) error {
logger.Debugw(ctx, "unsubscribe-for-response", log.Fields{"trnsId": trnsId})
kp.deleteFromTransactionIdToChannelMap(trnsId)
return nil
}
func (kp *interContainerProxy) EnableLivenessChannel(ctx context.Context, enable bool) chan bool {
return kp.kafkaClient.EnableLivenessChannel(ctx, enable)
}
func (kp *interContainerProxy) EnableHealthinessChannel(ctx context.Context, enable bool) chan bool {
return kp.kafkaClient.EnableHealthinessChannel(ctx, enable)
}
func (kp *interContainerProxy) SendLiveness(ctx context.Context) error {
return kp.kafkaClient.SendLiveness(ctx)
}
//formatRequest formats a request to send over kafka and returns an InterContainerMessage message on success
//or an error on failure
func encodeRequest(ctx context.Context, rpc string, toTopic *Topic, replyTopic *Topic, key string, kvArgs ...*KVArg) (*ic.InterContainerMessage, error) {
requestHeader := &ic.Header{
Id: uuid.New().String(),
Type: ic.MessageType_REQUEST,
FromTopic: replyTopic.Name,
ToTopic: toTopic.Name,
KeyTopic: key,
Timestamp: ptypes.TimestampNow(),
}
requestBody := &ic.InterContainerRequestBody{
Rpc: rpc,
ResponseRequired: true,
ReplyToTopic: replyTopic.Name,
}
for _, arg := range kvArgs {
if arg == nil {
// In case the caller sends an array with empty args
continue
}
var marshalledArg *any.Any
var err error
// ascertain the value interface type is a proto.Message
protoValue, ok := arg.Value.(proto.Message)
if !ok {
logger.Warnw(ctx, "argument-value-not-proto-message", log.Fields{"error": ok, "Value": arg.Value})
err := errors.New("argument-value-not-proto-message")
return nil, err
}
if marshalledArg, err = ptypes.MarshalAny(protoValue); err != nil {
logger.Warnw(ctx, "cannot-marshal-request", log.Fields{"error": err})
return nil, err
}
protoArg := &ic.Argument{
Key: arg.Key,
Value: marshalledArg,
}
requestBody.Args = append(requestBody.Args, protoArg)
}
var marshalledData *any.Any
var err error
if marshalledData, err = ptypes.MarshalAny(requestBody); err != nil {
logger.Warnw(ctx, "cannot-marshal-request", log.Fields{"error": err})
return nil, err
}
request := &ic.InterContainerMessage{
Header: requestHeader,
Body: marshalledData,
}
return request, nil
}
func decodeResponse(ctx context.Context, response *ic.InterContainerMessage) (*ic.InterContainerResponseBody, error) {
// Extract the message body
responseBody := ic.InterContainerResponseBody{}
if err := ptypes.UnmarshalAny(response.Body, &responseBody); err != nil {
logger.Warnw(ctx, "cannot-unmarshal-response", log.Fields{"error": err})
return nil, err
}
//logger.Debugw(ctx, "response-decoded-successfully", log.Fields{"response-status": &responseBody.Success})
return &responseBody, nil
}