Add HTTPClient interface to Pusher struct

Signed-off-by: NghiaLT <nghialt.11@gmail.com>

prometheus/push/http.go

@@ -0,0 +1,21 @@
+// Copyright 2019 The Prometheus Authors
+// 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 push
+
+import "net/http"
+
+// HTTPClient is a interface for http client
+type HTTPClient interface {
+	Do(*http.Request) (*http.Response, error)
+}

prometheus/push/push.go

@@ -61,7 +61,7 @@ type Pusher struct {
 	gatherers  prometheus.Gatherers
 	registerer prometheus.Registerer
 
-	client             *http.Client
+	client             HTTPClient
 	useBasicAuth       bool
 	username, password string
 
@@ -170,7 +170,7 @@ func (p *Pusher) Grouping(name, value string) *Pusher {
 
 // Client sets a custom HTTP client for the Pusher. For convenience, this method
 // returns a pointer to the Pusher itself.
-func (p *Pusher) Client(c *http.Client) *Pusher {
+func (p *Pusher) Client(c HTTPClient) *Pusher {
 	p.client = c
 	return p
 }