client/client.go

@@ -49,6 +49,7 @@ type Message interface {
 	Topic() string
 	Payload() interface{}
 	ContentType() string
+	Metadata() metadata.Metadata
 }
 
 // Request is the interface for a synchronous request used by Call or Stream

client/lookup.go

@@ -12,7 +12,7 @@ import (
 type LookupFunc func(context.Context, Request, CallOptions) ([]string, error)
 
 // LookupRoute for a request using the router and then choose one using the selector
-func LookupRoute(ctx context.Context, req Request, opts CallOptions) ([]string, error) {
+func LookupRoute(_ context.Context, req Request, opts CallOptions) ([]string, error) {
 	// check to see if an address was provided as a call option
 	if len(opts.Address) > 0 {
 		return opts.Address, nil

client/noop.go

@@ -139,6 +139,10 @@ func (n *noopMessage) ContentType() string {
 	return n.opts.ContentType
 }
 
+func (n *noopMessage) Metadata() metadata.Metadata {
+	return n.opts.Metadata
+}
+
 func (n *noopClient) newCodec(contentType string) (codec.Codec, error) {
 	if cf, ok := n.opts.Codecs[contentType]; ok {
 		return cf, nil

client/options.go

@@ -8,6 +8,7 @@ import (
 	"go.unistack.org/micro/v3/broker"
 	"go.unistack.org/micro/v3/codec"
 	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
 	"go.unistack.org/micro/v3/meter"
 	"go.unistack.org/micro/v3/network/transport"
 	"go.unistack.org/micro/v3/register"
@@ -128,7 +129,7 @@ type PublishOptions struct {
 
 // NewMessageOptions creates message options struct
 func NewMessageOptions(opts ...MessageOption) MessageOptions {
-	options := MessageOptions{}
+	options := MessageOptions{Metadata: metadata.New(1)}
 	for _, o := range opts {
 		o(&options)
 	}
@@ -137,7 +138,10 @@ func NewMessageOptions(opts ...MessageOption) MessageOptions {
 
 // MessageOptions holds client message options
 type MessageOptions struct {
+	// Metadata additional metadata
+	Metadata metadata.Metadata
 	// ContentType specify content-type of message
+	// deprecated
 	ContentType string
 }
 
@@ -517,6 +521,7 @@ func WithSelectOptions(sops ...selector.SelectOption) CallOption {
 // Deprecated
 func WithMessageContentType(ct string) MessageOption {
 	return func(o *MessageOptions) {
+		o.Metadata.Set(metadata.HeaderContentType, ct)
 		o.ContentType = ct
 	}
 }
@@ -524,10 +529,18 @@ func WithMessageContentType(ct string) MessageOption {
 // MessageContentType sets the message content type
 func MessageContentType(ct string) MessageOption {
 	return func(o *MessageOptions) {
+		o.Metadata.Set(metadata.HeaderContentType, ct)
 		o.ContentType = ct
 	}
 }
 
+// MessageMetadata sets the message metadata
+func MessageMetadata(k, v string) MessageOption {
+	return func(o *MessageOptions) {
+		o.Metadata.Set(k, v)
+	}
+}
+
 // StreamingRequest specifies that request is streaming
 func StreamingRequest(b bool) RequestOption {
 	return func(o *RequestOptions) {

client/retry.go

@@ -20,7 +20,7 @@ func RetryNever(ctx context.Context, req Request, retryCount int, err error) (bo
 }
 
 // RetryOnError retries a request on a 500 or timeout error
-func RetryOnError(ctx context.Context, req Request, retryCount int, err error) (bool, error) {
+func RetryOnError(_ context.Context, _ Request, _ int, err error) (bool, error) {
 	if err == nil {
 		return false, nil
 	}

config/config.go

@@ -23,6 +23,8 @@ var (
 	ErrInvalidStruct = errors.New("invalid struct specified")
 	// ErrWatcherStopped is returned when source watcher has been stopped
 	ErrWatcherStopped = errors.New("watcher stopped")
+	// ErrWatcherNotImplemented returned when config does not implement watch
+	ErrWatcherNotImplemented = errors.New("watcher not implemented")
 )
 
 // Config is an interface abstraction for dynamic configuration

config/default.go

@@ -2,7 +2,6 @@ package config
 
 import (
 	"context"
-	"fmt"
 	"reflect"
 	"strconv"
 	"strings"
@@ -271,7 +270,7 @@ func (c *defaultConfig) Name() string {
 }
 
 func (c *defaultConfig) Watch(ctx context.Context, opts ...WatchOption) (Watcher, error) {
-	return nil, fmt.Errorf("not implemented")
+	return nil, ErrWatcherNotImplemented
 }
 
 // NewConfig returns new default config source