Add a publisher in broker service and make everything work

broker-service/cmd/api/event/emitter.go

@@ -0,0 +1,53 @@
+package event
+
+import (
+	"log"
+
+	amqp "github.com/rabbitmq/amqp091-go"
+)
+
+type Emitter struct {
+	conn *amqp.Connection
+}
+
+func NewEmitter(conn *amqp.Connection) (Emitter, error) {
+	emitter := Emitter{
+		conn: conn,
+	}
+
+	err := emitter.setup()
+	if err != nil {
+		return Emitter{}, err
+	}
+	return emitter, err
+}
+
+func (emitter *Emitter) setup() error {
+	channel, err := emitter.conn.Channel()
+	if err != nil {
+		return err
+	}
+	defer channel.Close()
+
+	return declaireExchange(channel)
+}
+
+func (emitter *Emitter) Push(event string, severity string) error {
+	ch, err := emitter.conn.Channel()
+	if err != nil {
+		return err
+	}
+	defer ch.Close()
+
+	log.Println("Pushing to channel")
+
+	err = ch.Publish("logs_topic", severity, false, false, amqp.Publishing{
+		ContentType: "text/plain",
+		Body:        []byte(event),
+	})
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

broker-service/cmd/api/event/event.go

@@ -0,0 +1,28 @@
+package event
+
+import (
+	amqp "github.com/rabbitmq/amqp091-go"
+)
+
+func declaireExchange(ch *amqp.Channel) error {
+	return ch.ExchangeDeclare(
+		"logs_topic", // name
+		"topic",      // type
+		true,         // durable?
+		false,        // auto-deleted?
+		false,        // internal?
+		false,        // no-wait?
+		nil,          // arguments?
+	)
+}
+
+func declaireRandomQueue(ch *amqp.Channel) (amqp.Queue, error) {
+	return ch.QueueDeclare(
+		"",    // name
+		false, // durable
+		false, // delete when unused
+		true,  // exclusive
+		false, // nowait
+		nil,   // table
+	)
+}

broker-service/cmd/api/handlers.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"broker/cmd/api/event"
 	"bytes"
 	"encoding/json"
 	"errors"
@@ -54,7 +55,8 @@ func (app *Config) HandleSubmission(w http.ResponseWriter, r *http.Request) {
 	case "auth":
 		app.authenticate(w, requestPayload.Auth)
 	case "log":
-		app.LogItem(w, requestPayload.Log)
+		// app.LogItem(w, requestPayload.Log)
+		app.logEventViaRabbit(w, requestPayload.Log)
 	case "mail":
 		app.SendMail(w, requestPayload.Mail)
 	default:
@@ -176,3 +178,37 @@ func (app *Config) callService(w http.ResponseWriter, ms Microservice) {
 
 	app.writeJSON(w, http.StatusOK, payload)
 }
+
+func (app *Config) logEventViaRabbit(w http.ResponseWriter, l LogPayload) {
+	err := app.pushToQueue(l.Name, l.Data)
+	if err != nil {
+		app.errorJSON(w, err)
+		return
+	}
+
+	var payload jsonResponse
+	payload.Error = false
+	payload.Message = "logged via RabbitMQ"
+
+	app.writeJSON(w, http.StatusOK, payload)
+}
+
+func (app *Config) pushToQueue(name, msg string) error {
+	emitter, err := event.NewEmitter(app.Rabbit)
+	if err != nil {
+		return err
+	}
+
+	payload := LogPayload{
+		Name: name,
+		Data: msg,
+	}
+
+	j, _ := json.MarshalIndent(&payload, "", "\t")
+	err = emitter.Push(string(j), "log.INFO")
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

broker-service/cmd/api/main.go

@@ -3,15 +3,32 @@ package main
 import (
 	"fmt"
 	"log"
+	"math"
 	"net/http"
+	"os"
+	"time"
+
+	amqp "github.com/rabbitmq/amqp091-go"
 )
 
 const webPort = "80"
 
-type Config struct{}
+type Config struct {
+	Rabbit *amqp.Connection
+}
 
 func main() {
-	app := Config{}
+	// try to connect to rabbitmq
+	rabbitConn, err := connect()
+	if err != nil {
+		log.Println(err)
+		os.Exit(1)
+	}
+	defer rabbitConn.Close()
+	log.Println("Connected to RabbitMQ")
+	app := Config{
+		Rabbit: rabbitConn,
+	}
 
 	log.Printf("Starting broker service on port %s\n", webPort)
 
@@ -21,8 +38,36 @@ func main() {
 		Handler: app.routes(),
 	}
 
-	err := srv.ListenAndServe()
+	err = srv.ListenAndServe()
 	if err != nil {
 		log.Panic(err)
 	}
 }
+
+func connect() (*amqp.Connection, error) {
+	var counts int64
+	var connection *amqp.Connection
+
+	// don't continue until rabbit is ready
+	for {
+		c, err := amqp.Dial("amqp://guest:guest@rabbitmq") // XXX: credentials
+		if err != nil {
+			fmt.Println("RabbitMQ not yet ready...")
+			counts++
+		} else {
+			connection = c
+			break
+		}
+
+		if counts > 5 {
+			fmt.Println(err)
+			return nil, err
+		}
+
+		backOff := time.Duration(math.Pow(float64(counts), 2) * float64(time.Second))
+		log.Println("backing off...")
+		time.Sleep(backOff)
+	}
+
+	return connection, nil
+}

broker-service/go.mod

@@ -6,3 +6,5 @@ require (
 	github.com/go-chi/chi/v5 v5.1.0
 	github.com/go-chi/cors v1.2.1
 )
+
+require github.com/rabbitmq/amqp091-go v1.10.0

broker-service/go.sum

@@ -2,3 +2,7 @@ github.com/go-chi/chi/v5 v5.1.0 h1:acVI1TYaD+hhedDJ3r54HyA6sExp3HfXq7QWEEY/xMw=
 github.com/go-chi/chi/v5 v5.1.0/go.mod h1:DslCQbL2OYiznFReuXYUmQ2hGd1aDpCnlMNITLSKoi8=
 github.com/go-chi/cors v1.2.1 h1:xEC8UT3Rlp2QuWNEr4Fs/c2EAGVKBwy/1vHx3bppil4=
 github.com/go-chi/cors v1.2.1/go.mod h1:sSbTewc+6wYHBBCW7ytsFSn836hqM7JxpglAy2Vzc58=
+github.com/rabbitmq/amqp091-go v1.10.0 h1:STpn5XsHlHGcecLmMFCtg7mqq0RnD+zFr4uzukfVhBw=
+github.com/rabbitmq/amqp091-go v1.10.0/go.mod h1:Hy4jKW5kQART1u+JkDTF9YYOQUHXqMuhrgxOEeS7G4o=
+go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
+go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=