Add emitter

README.md

@@ -2,7 +2,7 @@
 
 # Go channels at horizontal scale [![Build Status](https://travis-ci.org/matryer/vice.svg?branch=master)](https://travis-ci.org/matryer/vice)
 
-* Use Go channels transparently over a [messaging queue technology of your choice](https://github.com/matryer/vice/tree/master/queues) (Currently [NATS](http://nats.io), [Redis](http://redis.io) or [NSQ](http://nsq.io), [Amazon SQS](https://aws.amazon.com/sqs/))
+* Use Go channels transparently over a [messaging queue technology of your choice](https://github.com/matryer/vice/tree/master/queues) (Currently [NATS](http://nats.io), [Redis](http://redis.io), [NSQ](http://nsq.io), [Amazon SQS](https://aws.amazon.com/sqs/), or [Emitter](https://emitter.io))
 * Swap `vice.Transport` to change underlying queueing technologies transparently
 * Write idiomatic Go code instead of learning queue specific APIs
 * Develop against in-memory implementation before putting it into the wild

docs/writing-transports.md

@@ -15,7 +15,7 @@ package my_transport
 
 import (
 	"testing"
-	"github.com/matryer/vice/vicetest"
+	"github.com/matryer/vice/v2/vicetest"
 )
 
 func TestTransport(t *testing.T) {

example/emitter/README.md

@@ -0,0 +1,24 @@
+# Emitter: Example Vice service
+
+## Running
+
+1. In a shell, install Emitter [https://emitter.io/download/](https://emitter.io/download/)
+   - `go install github.com/emitter-io/emitter@latest && emitter`
+   - The first run of emitter will create an `emitter.conf` file and
+     print a new license key and a new secret key to stdout.
+2. In the same shell, save the new license in an environment variable:
+   - `export EMITTER_LICENSE=...`
+3. In the same shell, start `emitter` again:
+   - `emitter |& tee emitter.log`
+4. In a new shell, save the new secret key in an environment variable:
+   - `export EMITTER_SECRET_KEY=...`
+   then navigate to `example/emitter/server` and execute it with `go run main.go`
+5. In another new shell, save the new secret key in an environment variable:
+   - `export EMITTER_SECRET_KEY=...`
+   then navigate to `example/emitter/client` and execute it with `go run main.go`
+6. Type in names into the client, and see the responses coming from the service
+
+Note that there is no reason why you can start up _multiple_ servers and
+_multiple_ clients, but realize that a message from a client will only be
+received (and responded to) by one of the running servers and likewise the
+response will be randomly received by one of the clients.

example/emitter/client/main.go

@@ -0,0 +1,58 @@
+// client is a simple Greeter client that uses the emitter transport.
+
+package main
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"log"
+	"os"
+	"os/signal"
+
+	"github.com/matryer/vice/v2/queues/emitter"
+)
+
+func main() {
+	ctx := context.Background()
+	ctx, cancel := context.WithCancel(ctx)
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, os.Interrupt)
+	defer func() {
+		signal.Stop(c)
+		cancel()
+	}()
+	go func() {
+		select {
+		case <-c:
+			cancel()
+		case <-ctx.Done():
+		}
+	}()
+	transport := emitter.New()
+	names := transport.Send("names")
+	greetings := transport.Receive("greetings")
+	go func() {
+		for greeting := range greetings {
+			fmt.Println(string(greeting))
+		}
+	}()
+	go func() {
+		fmt.Println("Type some names to send through the |names| channel:")
+		s := bufio.NewScanner(os.Stdin)
+		for s.Scan() {
+			b := s.Bytes()
+			if len(b) == 0 {
+				continue
+			}
+			names <- b
+		}
+		if err := s.Err(); err != nil {
+			log.Println(err)
+		}
+	}()
+	<-ctx.Done()
+	transport.Stop()
+	<-transport.Done()
+	log.Println("transport stopped")
+}

example/emitter/server/main.go

@@ -0,0 +1,52 @@
+// server is a simple Greeter server that uses the emitter transport.
+
+package main
+
+import (
+	"context"
+	"log"
+	"time"
+
+	"github.com/matryer/vice/v2/queues/emitter"
+)
+
+// To run this, install emitter and start it with the "emitter" command.
+// Run this program:
+//   $ export EMITTER_SECRET_KEY=...
+//   $ go run main.go
+// Then use the "example/emitter/client" program to send names to the server.
+
+const runDuration = 1 * time.Minute
+
+// Greeter is a service that greets people.
+func Greeter(ctx context.Context, names <-chan []byte, greetings chan<- []byte, errs <-chan error) {
+	for {
+		select {
+		case <-ctx.Done():
+			log.Println("finished")
+			return
+		case err := <-errs:
+			log.Fatalf("an error occurred: %v", err)
+		case name := <-names:
+			greeting := "Hello " + string(name)
+			greetings <- []byte(greeting)
+			log.Printf("Sent greeting: %v", greeting)
+		}
+	}
+}
+
+func main() {
+	ctx := context.Background()
+	ctx, cancel := context.WithTimeout(ctx, runDuration)
+	defer cancel()
+	transport := emitter.New()
+	defer func() {
+		transport.Stop()
+		<-transport.Done()
+	}()
+	names := transport.Receive("names")
+	greetings := transport.Send("greetings")
+	log.Printf("Greeter server listening on 'names' channel and responding on 'greetings' channel...")
+	log.Printf("Note that this server will automatically shut down in %v", runDuration)
+	Greeter(ctx, names, greetings, transport.ErrChan())
+}

example/greeter/client/main.go

@@ -8,7 +8,7 @@ import (
 	"os"
 	"os/signal"
 
-	"github.com/matryer/vice/queues/nsq"
+	"github.com/matryer/vice/v2/queues/nsq"
 )
 
 func main() {

example/greeter/service/main.go

@@ -5,7 +5,7 @@ import (
 	"log"
 	"time"
 
-	"github.com/matryer/vice/queues/nsq"
+	"github.com/matryer/vice/v2/queues/nsq"
 )
 
 // To run this, install NSQ and start it with nsqd command.

go.mod

@@ -4,25 +4,27 @@ go 1.17
 
 require (
 	github.com/aws/aws-sdk-go v1.44.16
+	github.com/emitter-io/go/v2 v2.0.9
 	github.com/go-redis/redis v6.15.9+incompatible
 	github.com/gofrs/uuid v4.2.0+incompatible
 	github.com/matryer/is v1.4.0
-	github.com/matryer/vice v1.0.0
 	github.com/maxbrunsfeld/counterfeiter/v6 v6.5.0
 	github.com/nats-io/nats.go v1.15.0
 	github.com/nats-io/stan.go v0.10.2
 	github.com/nsqio/go-nsq v1.1.0
 	github.com/streadway/amqp v1.0.0
-	github.com/stretchr/testify v1.7.1
+	github.com/stretchr/testify v1.8.0
 	golang.org/x/lint v0.0.0-20210508222113-6edffad5e616
 	honnef.co/go/tools v0.3.2
 )
 
 require (
 	github.com/BurntSushi/toml v0.4.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/eclipse/paho.mqtt.golang v1.4.1 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/snappy v0.0.1 // indirect
+	github.com/gorilla/websocket v1.4.2 // indirect
 	github.com/jmespath/go-jmespath v0.4.0 // indirect
 	github.com/kr/pretty v0.3.0 // indirect
 	github.com/nats-io/nats-server/v2 v2.8.2 // indirect
@@ -35,8 +37,10 @@ require (
 	golang.org/x/crypto v0.0.0-20220315160706-3147a52a75dd // indirect
 	golang.org/x/exp/typeparams v0.0.0-20220218215828-6cf2b201936e // indirect
 	golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 // indirect
+	golang.org/x/net v0.0.0-20220225172249-27dd8689420f // indirect
+	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c // indirect
 	golang.org/x/sys v0.0.0-20220412211240-33da011f77ad // indirect
 	golang.org/x/tools v0.1.11-0.20220513221640-090b14e8501f // indirect
 	google.golang.org/protobuf v1.28.0 // indirect
-	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -15,6 +15,11 @@ github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ3
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/eclipse/paho.mqtt.golang v1.2.0/go.mod h1:H9keYFcgq3Qr5OUJm/JZI/i6U7joQ8SYLhZwfeOo6Ts=
+github.com/eclipse/paho.mqtt.golang v1.4.1 h1:tUSpviiL5G3P9SZZJPC4ZULZJsxQKXxfENpMvdbAXAI=
+github.com/eclipse/paho.mqtt.golang v1.4.1/go.mod h1:JGt0RsEwEX+Xa/agj90YJ9d9DH2b7upDZMK9HRbFvCA=
+github.com/emitter-io/go/v2 v2.0.9 h1:qA+cnG3kS2uLzo5ETFY6zbHBGl+FmNj0cGf3da7foA4=
+github.com/emitter-io/go/v2 v2.0.9/go.mod h1:St++epE1u/6ueCVw47xhu4shpkGNxKRVtkWv4Xi33mg=
 github.com/fatih/color v1.7.0 h1:DkWD4oS2D8LGGgTQ6IvwJJXSL5Vp2ffcQg58nFV38Ys=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
@@ -46,6 +51,8 @@ github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/pprof v0.0.0-20210407192527-94a9f03dee38/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
+github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
+github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/hashicorp/go-cleanhttp v0.5.0/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=
 github.com/hashicorp/go-hclog v0.9.1/go.mod h1:5CU+agLiy3J7N7QjHK5d05KxGsuXiQLrjA0H7acj2lQ=
 github.com/hashicorp/go-hclog v1.1.0 h1:QsGcniKx5/LuX2eYoeL+Np3UKYPNaN7YKpTh29h8rbw=
@@ -146,11 +153,13 @@ github.com/sclevine/spec v1.4.0/go.mod h1:LvpgJaFyvQzRvc1kaDs0bulYwzC70PbiYjC4Qn
 github.com/streadway/amqp v1.0.0 h1:kuuDrUJFZL1QYL9hUNuCxNObNzB0bV/ZG5jV3RWAQgo=
 github.com/streadway/amqp v1.0.0/go.mod h1:AZpEONHx3DKn8O/DFsRAY58/XVQiIPMTMB1SddzLXVw=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
-github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/tv42/httpunix v0.0.0-20150427012821-b75d8614f926/go.mod h1:9ESjWnEqriFuLhtthL60Sar/7RFoluCcXsuvEwTV5KM=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
@@ -180,6 +189,8 @@ golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20200425230154-ff2c4b7c35a0/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
+golang.org/x/net v0.0.0-20200513185701-a91f0712d120/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
 golang.org/x/net v0.0.0-20200520004742-59133d7f0dd7/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
 golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
@@ -195,6 +206,7 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c h1:5KslGYwFpkhGh+Q16bwMP3cOontH8FOep7tGV86Y7SQ=
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190130150945-aca44879d564/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -267,7 +279,8 @@ gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 honnef.co/go/tools v0.3.2 h1:ytYb4rOqyp1TSa2EPvNVwtPQJctSELKaMyLfqNP4+34=
 honnef.co/go/tools v0.3.2/go.mod h1:jzwdWgg7Jdq75wlfblQxO4neNaFFSvgc1tD5Wv8U0Yw=

queues/emitter/README.md

@@ -0,0 +1,8 @@
+# Emitter
+
+[Emitter](https://emitter.io) is a real-time communication service
+for connecting online devices. The Publish-Subscribe messaging API
+is built for speed and security.
+
+Kelindar has made a number of excellent videos about Emitter on
+his [YouTube channel](https://www.youtube.com/c/Kelindar/videos).

queues/emitter/client.go

@@ -0,0 +1,23 @@
+package emitter
+
+import (
+	"errors"
+	"fmt"
+
+	eio "github.com/emitter-io/go/v2"
+)
+
+func (t *Transport) newClient() (*eio.Client, error) {
+	if t.emitterAddress == "" {
+		return nil, errors.New("missing emitter address")
+	}
+	if t.secretKey == "" {
+		return nil, errors.New("missing emitter secret key")
+	}
+
+	c := eio.NewClient(eio.WithBrokers(t.emitterAddress), eio.WithAutoReconnect(true))
+	if err := c.Connect(); err != nil {
+		return nil, fmt.Errorf("emitter.Connect(%q): %w - is the emitter service running?", t.emitterAddress, err)
+	}
+	return c, nil
+}