Back out matrix-org/dendrite#2421 by restoring http.Clients

This creates problems with non-HTTPS endpoints and should fix #2444.

internal/pushgateway/client.go

@@ -3,28 +3,32 @@ package pushgateway
 import (
 	"bytes"
 	"context"
+	"crypto/tls"
 	"encoding/json"
 	"fmt"
 	"net/http"
 	"time"
 
-	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/opentracing/opentracing-go"
 )
 
 type httpClient struct {
-	hc *gomatrixserverlib.Client
+	hc *http.Client
 }
 
 // NewHTTPClient creates a new Push Gateway client.
 func NewHTTPClient(disableTLSValidation bool) Client {
-	return &httpClient{
-		hc: gomatrixserverlib.NewClient(
-			gomatrixserverlib.WithTimeout(time.Second*30),
-			gomatrixserverlib.WithKeepAlives(false),
-			gomatrixserverlib.WithSkipVerify(disableTLSValidation),
-		),
+	hc := &http.Client{
+		Timeout: 30 * time.Second,
+		Transport: &http.Transport{
+			DisableKeepAlives: true,
+			TLSClientConfig: &tls.Config{
+				InsecureSkipVerify: disableTLSValidation,
+			},
+			Proxy: http.ProxyFromEnvironment,
+		},
 	}
+	return &httpClient{hc: hc}
 }
 
 func (h *httpClient) Notify(ctx context.Context, url string, req *NotifyRequest, resp *NotifyResponse) error {
@@ -41,7 +45,7 @@ func (h *httpClient) Notify(ctx context.Context, url string, req *NotifyRequest,
 	}
 	hreq.Header.Set("Content-Type", "application/json")
 
-	hresp, err := h.hc.DoHTTPRequest(ctx, hreq)
+	hresp, err := h.hc.Do(hreq)
 	if err != nil {
 		return err
 	}