Use default ports for the schemes when dialing (#7960)

Fixes #7946

pkg/event/target/elasticsearch.go

@@ -19,7 +19,6 @@ package target
 import (
 	"context"
 	"fmt"
-	"net"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -83,8 +82,14 @@ func (target *ElasticsearchTarget) Save(eventData event.Event) error {
 	if target.store != nil {
 		return target.store.Put(eventData)
 	}
-	if _, err := net.Dial("tcp", target.args.URL.Host); err != nil {
+	if dErr := target.args.URL.DialHTTP(); dErr != nil {
-		return errNotConnected
+		if urlErr, ok := dErr.(*url.Error); ok {
+			// To treat "connection refused" errors as errNotConnected.
+			if IsConnRefusedErr(urlErr.Err) {
+				return errNotConnected
+			}
+		}
+		return dErr
 	}
 	return target.send(eventData)
 }
@@ -151,8 +156,14 @@ func (target *ElasticsearchTarget) Send(eventKey string) error {
 		}
 	}
 
-	if _, err := net.Dial("tcp", target.args.URL.Host); err != nil {
+	if dErr := target.args.URL.DialHTTP(); dErr != nil {
-		return errNotConnected
+		if urlErr, ok := dErr.(*url.Error); ok {
+			// To treat "connection refused" errors as errNotConnected.
+			if IsConnRefusedErr(urlErr.Err) {
+				return errNotConnected
+			}
+		}
+		return dErr
 	}
 
 	eventData, eErr := target.store.Get(eventKey)
@@ -227,10 +238,10 @@ func NewElasticsearchTarget(id string, args ElasticsearchArgs, doneCh <-chan str
 		}
 	}
 
-	_, derr := net.Dial("tcp", args.URL.Host)
+	dErr := args.URL.DialHTTP()
-	if derr != nil {
+	if dErr != nil {
 		if store == nil {
-			return nil, derr
+			return nil, dErr
 		}
 	} else {
 		client, err = newClient(args)

pkg/event/target/webhook.go

@@ -82,15 +82,16 @@ func (target *WebhookTarget) Save(eventData event.Event) error {
 	if target.store != nil {
 		return target.store.Put(eventData)
 	}
-	urlStr, pErr := xnet.ParseURL(target.args.Endpoint.String())
+	u, pErr := xnet.ParseURL(target.args.Endpoint.String())
 	if pErr != nil {
 		return pErr
 	}
-	_, dErr := net.Dial("tcp", urlStr.Host)
+	if dErr := u.DialHTTP(); dErr != nil {
-	if dErr != nil {
+		if urlErr, ok := dErr.(*url.Error); ok {
-		// To treat "connection refused" errors as errNotConnected.
+			// To treat "connection refused" errors as errNotConnected.
-		if IsConnRefusedErr(dErr) {
+			if IsConnRefusedErr(urlErr.Err) {
-			return errNotConnected
+				return errNotConnected
+			}
 		}
 		return dErr
 	}
@@ -136,15 +137,16 @@ func (target *WebhookTarget) send(eventData event.Event) error {
 // Send - reads an event from store and sends it to webhook.
 func (target *WebhookTarget) Send(eventKey string) error {
 
-	urlStr, pErr := xnet.ParseURL(target.args.Endpoint.String())
+	u, pErr := xnet.ParseURL(target.args.Endpoint.String())
 	if pErr != nil {
 		return pErr
 	}
-	_, dErr := net.Dial("tcp", urlStr.Host)
+	if dErr := u.DialHTTP(); dErr != nil {
-	if dErr != nil {
+		if urlErr, ok := dErr.(*url.Error); ok {
-		// To treat "connection refused" errors as errNotConnected.
+			// To treat "connection refused" errors as errNotConnected.
-		if IsConnRefusedErr(dErr) {
+			if IsConnRefusedErr(urlErr.Err) {
-			return errNotConnected
+				return errNotConnected
+			}
 		}
 		return dErr
 	}

pkg/net/url.go

@@ -19,9 +19,12 @@ package net
 import (
 	"encoding/json"
 	"errors"
+	"net"
+	"net/http"
 	"net/url"
 	"path"
 	"strings"
+	"time"
 )
 
 // URL - improved JSON friendly url.URL.
@@ -79,6 +82,27 @@ func (u *URL) UnmarshalJSON(data []byte) (err error) {
 	return nil
 }
 
+// DialHTTP - dials the url to check the connection.
+func (u URL) DialHTTP() error {
+	var client = &http.Client{
+		Transport: &http.Transport{
+			DialContext: (&net.Dialer{
+				Timeout: 2 * time.Second,
+			}).DialContext,
+		},
+	}
+	req, err := http.NewRequest("POST", u.String(), nil)
+	if err != nil {
+		return err
+	}
+	resp, err := client.Do(req)
+	if err != nil {
+		return err
+	}
+	resp.Body.Close()
+	return nil
+}
+
 // ParseURL - parses string into URL.
 func ParseURL(s string) (u *URL, err error) {
 	var uu *url.URL