Add sourceInfo to NotificationEvent (#3937)

This change adds information like host, port and user-agent of the
client whose request triggered an event notification.

E.g, if someone uploads an object to a bucket using mc. If notifications
were configured on that bucket, the host, port and user-agent of mc
would be sent as part of event notification data.

Sample output:
```
"source": {
          "host": "127.0.0.1",
          "port": "55808",
          "userAgent": "Minio (linux; amd64) minio-go/2.0.4 mc ..."
}
```

cmd/bucket-handlers.go

@@ -20,6 +20,7 @@ import (
 	"encoding/base64"
 	"encoding/xml"
 	"io"
+	"net"
 	"net/http"
 	"net/url"
 	"path"
@@ -322,6 +323,13 @@ func (api objectAPIHandlers) DeleteMultipleObjectsHandler(w http.ResponseWriter,
 	// Write success response.
 	writeSuccessResponseXML(w, encodedSuccessResponse)
 
+	// Get host and port from Request.RemoteAddr failing which
+	// fill them with empty strings.
+	host, port, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		host, port = "", ""
+	}
+
 	// Notify deleted event for objects.
 	for _, dobj := range deletedObjects {
 		eventNotify(eventData{
@@ -331,6 +339,9 @@ func (api objectAPIHandlers) DeleteMultipleObjectsHandler(w http.ResponseWriter,
 				Name: dobj.ObjectName,
 			},
 			ReqParams: extractReqParams(r),
+			UserAgent: r.UserAgent(),
+			Host:      host,
+			Port:      port,
 		})
 	}
 }
@@ -520,12 +531,21 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 	w.Header().Set("ETag", `"`+objInfo.MD5Sum+`"`)
 	w.Header().Set("Location", getObjectLocation(bucket, object))
 
+	// Get host and port from Request.RemoteAddr.
+	host, port, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		host, port = "", ""
+	}
+
 	// Notify object created event.
 	defer eventNotify(eventData{
 		Type:      ObjectCreatedPost,
 		Bucket:    objInfo.Bucket,
 		ObjInfo:   objInfo,
 		ReqParams: extractReqParams(r),
+		UserAgent: r.UserAgent(),
+		Host:      host,
+		Port:      port,
 	})
 
 	if successRedirect != "" {

cmd/bucket-notification-datatypes.go

@@ -176,6 +176,14 @@ const (
 	eventVersion = "2.0"
 )
 
+// sourceInfo represents information on the client that triggered the
+// event notification.
+type sourceInfo struct {
+	Host      string `json:"host"`
+	Port      string `json:"port"`
+	UserAgent string `json:"userAgent"`
+}
+
 // NotificationEvent represents an Amazon an S3 bucket notification event.
 type NotificationEvent struct {
 	EventVersion      string            `json:"eventVersion"`
@@ -187,6 +195,7 @@ type NotificationEvent struct {
 	RequestParameters map[string]string `json:"requestParameters"`
 	ResponseElements  map[string]string `json:"responseElements"`
 	S3                eventMeta         `json:"s3"`
+	Source            sourceInfo        `json:"source"`
 }
 
 // Represents the minio sqs type and account id's.

cmd/event-notifier.go

@@ -29,6 +29,10 @@ import (
 	"github.com/Sirupsen/logrus"
 )
 
+const (
+	minioEventSource = "minio:s3"
+)
+
 type externalNotifier struct {
 	// Per-bucket notification config. This is updated via
 	// PutBucketNotification API.
@@ -82,6 +86,9 @@ type eventData struct {
 	Bucket    string
 	ObjInfo   ObjectInfo
 	ReqParams map[string]string
+	Host      string
+	Port      string
+	UserAgent string
 }
 
 // New notification event constructs a new notification event message from
@@ -114,7 +121,7 @@ func newNotificationEvent(event eventData) NotificationEvent {
 	// http://docs.aws.amazon.com/AmazonS3/latest/dev/notification-content-structure.html
 	nEvent := NotificationEvent{
 		EventVersion:      eventVersion,
-		EventSource:       eventSource,
+		EventSource:       minioEventSource,
 		AwsRegion:         region,
 		EventTime:         eventTime.Format(timeFormatAMZ),
 		EventName:         event.Type.String(),
@@ -135,6 +142,11 @@ func newNotificationEvent(event eventData) NotificationEvent {
 				ARN:           bucketARNPrefix + event.Bucket,
 			},
 		},
+		Source: sourceInfo{
+			Host:      event.Host,
+			Port:      event.Port,
+			UserAgent: event.UserAgent,
+		},
 	}
 
 	// Escape the object name. For example "red flower.jpg" becomes "red+flower.jpg".

cmd/object-handlers.go

@@ -20,6 +20,7 @@ import (
 	"encoding/hex"
 	"encoding/xml"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"net/url"
 	"path"
@@ -372,12 +373,21 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 	// Write success response.
 	writeSuccessResponseXML(w, encodedSuccessResponse)
 
+	// Get host and port from Request.RemoteAddr.
+	host, port, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		host, port = "", ""
+	}
+
 	// Notify object created event.
 	eventNotify(eventData{
 		Type:      ObjectCreatedCopy,
 		Bucket:    dstBucket,
 		ObjInfo:   objInfo,
 		ReqParams: extractReqParams(r),
+		UserAgent: r.UserAgent(),
+		Host:      host,
+		Port:      port,
 	})
 }
 
@@ -503,12 +513,21 @@ func (api objectAPIHandlers) PutObjectHandler(w http.ResponseWriter, r *http.Req
 	w.Header().Set("ETag", "\""+objInfo.MD5Sum+"\"")
 	writeSuccessResponseHeadersOnly(w)
 
+	// Get host and port from Request.RemoteAddr.
+	host, port, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		host, port = "", ""
+	}
+
 	// Notify object created event.
 	eventNotify(eventData{
 		Type:      ObjectCreatedPut,
 		Bucket:    bucket,
 		ObjInfo:   objInfo,
 		ReqParams: extractReqParams(r),
+		UserAgent: r.UserAgent(),
+		Host:      host,
+		Port:      port,
 	})
 }
 
@@ -930,12 +949,21 @@ func (api objectAPIHandlers) CompleteMultipartUploadHandler(w http.ResponseWrite
 	// Write success response.
 	writeSuccessResponseXML(w, encodedSuccessResponse)
 
+	// Get host and port from Request.RemoteAddr.
+	host, port, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		host, port = "", ""
+	}
+
 	// Notify object created event.
 	eventNotify(eventData{
 		Type:      ObjectCreatedCompleteMultipartUpload,
 		Bucket:    bucket,
 		ObjInfo:   objInfo,
 		ReqParams: extractReqParams(r),
+		UserAgent: r.UserAgent(),
+		Host:      host,
+		Port:      port,
 	})
 }
 
@@ -971,6 +999,12 @@ func (api objectAPIHandlers) DeleteObjectHandler(w http.ResponseWriter, r *http.
 	}
 	writeSuccessNoContent(w)
 
+	// Get host and port from Request.RemoteAddr.
+	host, port, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		host, port = "", ""
+	}
+
 	// Notify object deleted event.
 	eventNotify(eventData{
 		Type:   ObjectRemovedDelete,
@@ -979,5 +1013,8 @@ func (api objectAPIHandlers) DeleteObjectHandler(w http.ResponseWriter, r *http.
 			Name: object,
 		},
 		ReqParams: extractReqParams(r),
+		UserAgent: r.UserAgent(),
+		Host:      host,
+		Port:      port,
 	})
 }