feat: support for prometheus (#1784)

object/prometheus.go

@@ -0,0 +1,129 @@
+// Copyright 2023 The Casdoor Authors. All Rights Reserved.
+//
+// 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 object
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	"github.com/prometheus/client_model/go"
+)
+
+type PrometheusInfo struct {
+	APIThroughput   []GaugeVecInfo     `json:"apiThroughput"`
+	APILatency      []HistogramVecInfo `json:"apiLatency"`
+	TotalThroughput float64            `json:"totalThroughput"`
+}
+
+type GaugeVecInfo struct {
+	Method     string  `json:"method"`
+	Name       string  `json:"name"`
+	Throughput float64 `json:"throughput"`
+}
+
+type HistogramVecInfo struct {
+	Name    string `json:"name"`
+	Method  string `json:"method"`
+	Count   uint64 `json:"count"`
+	Latency string `json:"latency"`
+}
+
+var (
+	APIThroughput = promauto.NewGaugeVec(prometheus.GaugeOpts{
+		Name: "casdoor_api_throughput",
+		Help: "The throughput of each api access",
+	}, []string{"path", "method"})
+
+	APILatency = promauto.NewHistogramVec(prometheus.HistogramOpts{
+		Name: "casdoor_api_latency",
+		Help: "API processing latency in milliseconds",
+	}, []string{"path", "method"})
+
+	CpuUsage = promauto.NewGaugeVec(prometheus.GaugeOpts{
+		Name: "casdoor_cpu_usage",
+		Help: "Casdoor cpu usage",
+	}, []string{"cpuNum"})
+
+	MemoryUsage = promauto.NewGaugeVec(prometheus.GaugeOpts{
+		Name: "casdoor_memory_usage",
+		Help: "Casdoor memory usage in Byte",
+	}, []string{"type"})
+
+	TotalThroughput = promauto.NewGauge(prometheus.GaugeOpts{
+		Name: "casdoor_total_throughput",
+		Help: "The total throughput of casdoor",
+	})
+)
+
+func ClearThroughputPerSecond() {
+	// Clear the throughput every second
+	ticker := time.NewTicker(time.Second)
+	for range ticker.C {
+		APIThroughput.Reset()
+		TotalThroughput.Set(0)
+	}
+}
+
+func GetPrometheusInfo() (*PrometheusInfo, error) {
+	res := &PrometheusInfo{}
+	metricFamilies, err := prometheus.DefaultGatherer.Gather()
+	if err != nil {
+		return nil, err
+	}
+	for _, metricFamily := range metricFamilies {
+		switch metricFamily.GetName() {
+		case "casdoor_api_throughput":
+			res.APIThroughput = getGaugeVecInfo(metricFamily)
+		case "casdoor_api_latency":
+			res.APILatency = getHistogramVecInfo(metricFamily)
+		case "casdoor_total_throughput":
+			res.TotalThroughput = metricFamily.GetMetric()[0].GetGauge().GetValue()
+		}
+	}
+
+	return res, nil
+}
+
+func getHistogramVecInfo(metricFamily *io_prometheus_client.MetricFamily) []HistogramVecInfo {
+	var histogramVecInfos []HistogramVecInfo
+	for _, metric := range metricFamily.GetMetric() {
+		sampleCount := metric.GetHistogram().GetSampleCount()
+		sampleSum := metric.GetHistogram().GetSampleSum()
+		latency := sampleSum / float64(sampleCount)
+		histogramVecInfo := HistogramVecInfo{
+			Method:  metric.Label[0].GetValue(),
+			Name:    metric.Label[1].GetValue(),
+			Count:   sampleCount,
+			Latency: fmt.Sprintf("%.3f", latency),
+		}
+		histogramVecInfos = append(histogramVecInfos, histogramVecInfo)
+	}
+	return histogramVecInfos
+}
+
+func getGaugeVecInfo(metricFamily *io_prometheus_client.MetricFamily) []GaugeVecInfo {
+	var counterVecInfos []GaugeVecInfo
+	for _, metric := range metricFamily.GetMetric() {
+		counterVecInfo := GaugeVecInfo{
+			Method:     metric.Label[0].GetValue(),
+			Name:       metric.Label[1].GetValue(),
+			Throughput: metric.Gauge.GetValue(),
+		}
+		counterVecInfos = append(counterVecInfos, counterVecInfo)
+	}
+	return counterVecInfos
+}