make notification as separate package (#5294)

* Remove old notification files

* Add net package

* Add event package

* Modify minio to take new notification system

pkg/event/target/mqtt.go

@@ -0,0 +1,117 @@
+/*
+ * Minio Cloud Storage, (C) 2018 Minio, Inc.
+ *
+ * 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 target
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/json"
+	"net/url"
+	"time"
+
+	"github.com/eclipse/paho.mqtt.golang"
+	"github.com/minio/minio/pkg/event"
+	xnet "github.com/minio/minio/pkg/net"
+)
+
+// MQTTArgs - MQTT target arguments.
+type MQTTArgs struct {
+	Enable               bool           `json:"enable"`
+	Broker               xnet.URL       `json:"broker"`
+	Topic                string         `json:"topic"`
+	QoS                  byte           `json:"qos"`
+	ClientID             string         `json:"clientId"`
+	User                 string         `json:"username"`
+	Password             string         `json:"password"`
+	MaxReconnectInterval time.Duration  `json:"reconnectInterval"`
+	KeepAlive            time.Duration  `json:"keepAliveInterval"`
+	RootCAs              *x509.CertPool `json:"-"`
+}
+
+// MQTTTarget - MQTT target.
+type MQTTTarget struct {
+	id     event.TargetID
+	args   MQTTArgs
+	client mqtt.Client
+}
+
+// ID - returns target ID.
+func (target *MQTTTarget) ID() event.TargetID {
+	return target.id
+}
+
+// Send - sends event to MQTT.
+func (target *MQTTTarget) Send(eventData event.Event) error {
+	if !target.client.IsConnected() {
+		token := target.client.Connect()
+		if token.Wait() {
+			if err := token.Error(); err != nil {
+				return err
+			}
+		}
+	}
+
+	objectName, err := url.QueryUnescape(eventData.S3.Object.Key)
+	if err != nil {
+		return err
+	}
+	key := eventData.S3.Bucket.Name + "/" + objectName
+
+	data, err := json.Marshal(event.Log{eventData.EventName, key, []event.Event{eventData}})
+	if err != nil {
+		return err
+	}
+
+	token := target.client.Publish(target.args.Topic, target.args.QoS, false, string(data))
+
+	if token.Wait() {
+		return token.Error()
+	}
+
+	return nil
+}
+
+// Close - does nothing and available for interface compatibility.
+func (target *MQTTTarget) Close() error {
+	return nil
+}
+
+// NewMQTTTarget - creates new MQTT target.
+func NewMQTTTarget(id string, args MQTTArgs) (*MQTTTarget, error) {
+	options := &mqtt.ClientOptions{
+		ClientID:             args.ClientID,
+		CleanSession:         true,
+		Username:             args.User,
+		Password:             args.Password,
+		MaxReconnectInterval: args.MaxReconnectInterval,
+		KeepAlive:            args.KeepAlive,
+		TLSConfig:            tls.Config{RootCAs: args.RootCAs},
+	}
+	options.AddBroker(args.Broker.String())
+
+	client := mqtt.NewClient(options)
+	token := client.Connect()
+	if token.Wait() && token.Error() != nil {
+		return nil, token.Error()
+	}
+
+	return &MQTTTarget{
+		id:     event.TargetID{id, "mqtt"},
+		args:   args,
+		client: client,
+	}, nil
+}