add monitoring apis

pkg/client/prometheusclient.go

@@ -0,0 +1,106 @@
+/*
+Copyright 2018 The KubeSphere 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 client
+
+import (
+	"io/ioutil"
+	"net/http"
+	"net/url"
+
+	"github.com/emicklei/go-restful"
+	"github.com/golang/glog"
+	"github.com/pkg/errors"
+)
+
+const (
+	DefaultScheme            = "http"
+	DefaultPrometheusService = "prometheus-k8s.monitoring.svc"
+	DefaultPrometheusPort    = "9090"
+	PrometheusApiPath        = "/api/v1/"
+	PrometheusEndpointUrl    = DefaultScheme + "://" + DefaultPrometheusService + ":" + DefaultPrometheusPort + PrometheusApiPath
+)
+
+var client = &http.Client{}
+
+func SendRequest(postfix string, params string) string {
+	epurl := PrometheusEndpointUrl + postfix + params
+	//glog.Info("monitoring epurl:>", epurl)
+	response, err := client.Get(epurl)
+	if err != nil {
+		glog.Error(err)
+	} else {
+		defer response.Body.Close()
+
+		contents, err := ioutil.ReadAll(response.Body)
+
+		if err != nil {
+			glog.Error(err)
+		}
+		return string(contents)
+	}
+	return ""
+}
+
+func SendPrometheusRequest(request *restful.Request, recordingRule string) string {
+	paramsMap, bol, err := ParseRequestHeader(request)
+	if err != nil {
+		glog.Error(err)
+		return ""
+	}
+
+	var res = ""
+	var postfix = ""
+	if bol {
+		// range query
+		postfix = "query_range?"
+	} else {
+		// query
+		postfix = "query?"
+	}
+	paramsMap.Set("query", recordingRule)
+	params := paramsMap.Encode()
+	res = SendRequest(postfix, params)
+	return res
+}
+
+func ParseRequestHeader(request *restful.Request) (url.Values, bool, error) {
+	instantTime := request.QueryParameter("time")
+	start := request.QueryParameter("start")
+	end := request.QueryParameter("end")
+	step := request.QueryParameter("step")
+	timeout := request.QueryParameter("timeout")
+	if timeout == "" {
+		timeout = "30s"
+	}
+	// Whether query or query_range request
+	u := url.Values{}
+	if start != "" && end != "" && step != "" {
+		u.Set("start", start)
+		u.Set("end", end)
+		u.Set("step", step)
+		u.Set("timeout", timeout)
+		return u, true, nil
+	}
+	if instantTime != "" {
+		u.Set("time", instantTime)
+		u.Set("timeout", timeout)
+		return u, false, nil
+	} else {
+		//u.Set("time", strconv.FormatInt(int64(time.Now().Unix()), 10))
+		u.Set("timeout", timeout)
+		return u, false, nil
+	}
+
+	glog.Error("Parse request failed", u)
+	return u, false, errors.Errorf("Parse request failed")
+}