Re-add events package (#2761)

* Re-add events package

* run redis as a dep

* remove redis events

* fix: data race on event subscriber

* fix: data race in tests

* fix: store errors

* fix: lint issues

* feat: default stream

* Update file.go

---------

Co-authored-by: Brian Ketelsen <bketelsen@gmail.com>

Author: asim

cmd/cmd.go

@@ -23,6 +23,7 @@ import (
 	"go-micro.dev/v5/debug/profile/http"
 	"go-micro.dev/v5/debug/profile/pprof"
 	"go-micro.dev/v5/debug/trace"
+	"go-micro.dev/v5/events"
 	"go-micro.dev/v5/logger"
 	mprofile "go-micro.dev/v5/profile"
 	"go-micro.dev/v5/registry"
@@ -293,6 +294,7 @@ var (
 	DefaultCaches = map[string]func(...cache.Option) cache.Cache{
 		"redis": redis.NewRedisCache,
 	}
+	DefaultStreams = map[string]func(...events.Option) (events.Stream, error){}
 )
 
 func init() {
@@ -313,6 +315,7 @@ func newCmd(opts ...Option) Cmd {
 		DebugProfile: &profile.DefaultProfile,
 		Config:       &config.DefaultConfig,
 		Cache:        &cache.DefaultCache,
+		Stream:       &events.DefaultStream,
 
 		Brokers:       DefaultBrokers,
 		Clients:       DefaultClients,
@@ -376,7 +379,10 @@ func (c *cmd) Before(ctx *cli.Context) error {
 	if profileName != "" {
 		switch profileName {
 		case "local":
-			imported := mprofile.LocalProfile()
+			imported, ierr := mprofile.LocalProfile()
+			if ierr != nil {
+				return fmt.Errorf("failed to load local profile: %v", ierr)
+			}
 			*c.opts.Registry = imported.Registry
 			registry.DefaultRegistry = imported.Registry
 			*c.opts.Broker = imported.Broker
@@ -386,7 +392,10 @@ func (c *cmd) Before(ctx *cli.Context) error {
 			*c.opts.Transport = imported.Transport
 			transport.DefaultTransport = imported.Transport
 		case "nats":
-			imported := mprofile.NatsProfile()
+			imported, ierr := mprofile.NatsProfile()
+			if ierr != nil {
+				return fmt.Errorf("failed to load nats profile: %v", ierr)
+			}
 			// Set the registry
 			sopts, clopts := c.setRegistry(imported.Registry)
 			serverOpts = append(serverOpts, sopts...)
@@ -407,6 +416,11 @@ func (c *cmd) Before(ctx *cli.Context) error {
 			serverOpts = append(serverOpts, sopts...)
 			clientOpts = append(clientOpts, clopts...)
 
+			// Set the stream
+			sopts, clopts = c.setStream(imported.Stream)
+			serverOpts = append(serverOpts, sopts...)
+			clientOpts = append(clientOpts, clopts...)
+
 		// Add more profiles as needed
 		default:
 			return fmt.Errorf("unsupported profile: %s", profileName)
@@ -701,6 +715,17 @@ func (c *cmd) setRegistry(r registry.Registry) ([]server.Option, []client.Option
 	registry.DefaultRegistry = *c.opts.Registry
 	return serverOpts, clientOpts
 }
+func (c *cmd) setStream(s events.Stream) ([]server.Option, []client.Option) {
+	var serverOpts []server.Option
+	var clientOpts []client.Option
+	*c.opts.Stream = s
+	// TODO: do server and client need a Stream?
+	// serverOpts = append(serverOpts, server.Registry(*c.opts.Registry))
+	// clientOpts = append(clientOpts, client.Registry(*c.opts.Registry))
+
+	events.DefaultStream = *c.opts.Stream
+	return serverOpts, clientOpts
+}
 
 func (c *cmd) setBroker(b broker.Broker) ([]server.Option, []client.Option) {
 	var serverOpts []server.Option

cmd/options.go

@@ -10,6 +10,7 @@ import (
 	"go-micro.dev/v5/config"
 	"go-micro.dev/v5/debug/profile"
 	"go-micro.dev/v5/debug/trace"
+	"go-micro.dev/v5/events"
 	"go-micro.dev/v5/registry"
 	"go-micro.dev/v5/selector"
 	"go-micro.dev/v5/server"
@@ -42,13 +43,15 @@ type Options struct {
 	Broker     *broker.Broker
 	Auths      map[string]func(...auth.Option) auth.Auth
 	Store      *store.Store
+	Stream     *events.Stream
 	Configs    map[string]func(...config.Option) (config.Config, error)
 	Clients    map[string]func(...client.Option) client.Client
 	Registries map[string]func(...registry.Option) registry.Registry
 	Selectors  map[string]func(...selector.Option) selector.Selector
 	Servers    map[string]func(...server.Option) server.Server
 	Transports map[string]func(...transport.Option) transport.Transport
 	Stores     map[string]func(...store.Option) store.Store
+	Streams    map[string]func(...events.Option) events.Stream
 	Tracers    map[string]func(...trace.Option) trace.Tracer
 	Version    string
 
@@ -141,6 +144,13 @@ func Store(s *store.Store) Option {
 	}
 }
 
+func Stream(s *events.Stream) Option {
+	return func(o *Options) {
+		o.Stream = s
+		events.DefaultStream = *s
+	}
+}
+
 func Tracer(t *trace.Tracer) Option {
 	return func(o *Options) {
 		o.Tracer = t
@@ -169,6 +179,13 @@ func NewBroker(name string, b func(...broker.Option) broker.Broker) Option {
 	}
 }
 
+// New stream func.
+func NewStream(name string, b func(...events.Option) events.Stream) Option {
+	return func(o *Options) {
+		o.Streams[name] = b
+	}
+}
+
 // New cache func.
 func NewCache(name string, c func(...cache.Option) cache.Cache) Option {
 	return func(o *Options) {

events/events.go

@@ -0,0 +1,92 @@
+// Package events is for event streaming and storage
+package events
+
+import (
+	"encoding/json"
+	"errors"
+	"time"
+)
+
+var (
+	// DefaultStream is the default events stream implementation
+	DefaultStream Stream
+	// DefaultStore is the default events store implementation
+	DefaultStore Store
+)
+
+var (
+	// ErrMissingTopic is returned if a blank topic was provided to publish
+	ErrMissingTopic = errors.New("missing topic")
+	// ErrEncodingMessage is returned from publish if there was an error encoding the message option
+	ErrEncodingMessage = errors.New("error encoding message")
+)
+
+// Stream is an event streaming interface
+type Stream interface {
+	Publish(topic string, msg interface{}, opts ...PublishOption) error
+	Consume(topic string, opts ...ConsumeOption) (<-chan Event, error)
+}
+
+// Store is an event store interface
+type Store interface {
+	Read(topic string, opts ...ReadOption) ([]*Event, error)
+	Write(event *Event, opts ...WriteOption) error
+}
+
+type AckFunc func() error
+type NackFunc func() error
+
+// Event is the object returned by the broker when you subscribe to a topic
+type Event struct {
+	// ID to uniquely identify the event
+	ID string
+	// Topic of event, e.g. "registry.service.created"
+	Topic string
+	// Timestamp of the event
+	Timestamp time.Time
+	// Metadata contains the values the event was indexed by
+	Metadata map[string]string
+	// Payload contains the encoded message
+	Payload []byte
+
+	ackFunc  AckFunc
+	nackFunc NackFunc
+}
+
+// Unmarshal the events message into an object
+func (e *Event) Unmarshal(v interface{}) error {
+	return json.Unmarshal(e.Payload, v)
+}
+
+// Ack acknowledges successful processing of the event in ManualAck mode
+func (e *Event) Ack() error {
+	return e.ackFunc()
+}
+
+func (e *Event) SetAckFunc(f AckFunc) {
+	e.ackFunc = f
+}
+
+// Nack negatively acknowledges processing of the event (i.e. failure) in ManualAck mode
+func (e *Event) Nack() error {
+	return e.nackFunc()
+}
+
+func (e *Event) SetNackFunc(f NackFunc) {
+	e.nackFunc = f
+}
+
+// Publish an event to a topic
+func Publish(topic string, msg interface{}, opts ...PublishOption) error {
+	return DefaultStream.Publish(topic, msg, opts...)
+}
+
+// Consume to events
+func Consume(topic string, opts ...ConsumeOption) (<-chan Event, error) {
+	return DefaultStream.Consume(topic, opts...)
+}
+
+// Read events for a topic
+func Read(topic string, opts ...ReadOption) ([]*Event, error) {
+	return DefaultStore.Read(topic, opts...)
+}