Support to get the metric data from a prometheus metric api with basic auth enabled

docs/design/usage-based-scheduling.md

@@ -65,6 +65,9 @@ metrics:                               # metrics server related configuration
   type: prometheus                     # Optional, The metrics source type, prometheus by default, support "prometheus", "prometheus_adapt" and "elasticsearch"
   address: http://192.168.0.10:9090    # Mandatory, The metrics source address
   interval: 30s                        # Optional, The scheduler pull metrics from Prometheus with this interval, 30s by default
+  basicauth: "false"                   # Optional, The basic authentication configuration，false by default
+  username: ""                         # Optional, The prometheus username
+  password: ""                         # Optional, The prometheus password
   tls:                                 # Optional, The tls configuration
     insecureSkipVerify: "false"        # Optional, Skip the certificate verification, false by default
   elasticsearch:                       # Optional, The elasticsearch configuration

pkg/scheduler/metrics/source/basicauth.go

@@ -0,0 +1,23 @@
+package source
+
+import (
+	"net/http"
+	"encoding/base64"
+	"fmt"
+)
+
+type BasicAuthTransport struct {
+	Username string
+	Password string
+}
+
+func (bat BasicAuthTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	req.Header.Set("Authorization", fmt.Sprintf("Basic %s",
+		base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf("%s:%s",
+			bat.Username, bat.Password)))))
+	return http.DefaultTransport.RoundTrip(req)
+}
+
+func (bat *BasicAuthTransport) Client() *http.Client {
+	return &http.Client{Transport: bat}
+}

pkg/scheduler/metrics/source/metrics_client_prometheus.go

@@ -60,16 +60,29 @@ func (p *PrometheusMetricsClient) NodeMetricsAvg(ctx context.Context, nodeName s
 	klog.V(4).Infof("Get node metrics from Prometheus: %s", p.address)
 	var client api.Client
 	var err error
+	basicauth := p.conf["basicauth"] == "true"
 	insecureSkipVerify := p.conf["tls.insecureSkipVerify"] == "true"
-	tr := &http.Transport{
-		TLSClientConfig: &tls.Config{
-			InsecureSkipVerify: insecureSkipVerify,
-		},
+	if basicauth {
+		bat := &BasicAuthTransport{
+			Username: p.conf["username"],
+			Password: p.conf["password"],
+		}
+		client, err = api.NewClient(api.Config{
+			Address:      p.address,
+			RoundTripper: bat,
+		})
+	} else {
+		tr := &http.Transport{
+			TLSClientConfig: &tls.Config{
+				InsecureSkipVerify: insecureSkipVerify,
+			},
+		}
+		client, err = api.NewClient(api.Config{
+			Address:      p.address,
+			RoundTripper: tr,
+		})
 	}
-	client, err = api.NewClient(api.Config{
-		Address:      p.address,
-		RoundTripper: tr,
-	})
+
 	if err != nil {
 		return nil, err
 	}