feat: docs api design

pkg/middlewares/metrics/config.go

@@ -0,0 +1,29 @@
+package metrics
+
+import "github.com/gofiber/fiber/v2"
+
+// Config defines the config for middleware.
+type Config struct {
+	// Next defines a function to skip this middleware when returned true.
+	//
+	// Optional. Default: nil
+	Next func(c *fiber.Ctx) bool
+}
+
+// ConfigDefault is the default config
+var ConfigDefault = Config{
+	Next: nil,
+}
+
+// Helper function to set default values
+func configDefault(config ...Config) Config {
+	// Return default config if nothing provided
+	if len(config) < 1 {
+		return ConfigDefault
+	}
+
+	// Override default config
+	cfg := config[0]
+
+	return cfg
+}

pkg/middlewares/metrics/middleware.go

@@ -0,0 +1,135 @@
+package metrics
+
+import (
+	"strconv"
+	"time"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+const serviceName = "cp-service"
+
+var (
+	labels = prometheus.Labels{"service": serviceName}
+
+	KafkaConsumeSuccessCounter = promauto.NewCounterVec(
+		prometheus.CounterOpts{
+			Name:        prometheus.BuildFQName("cp", "kafka", "consume_success"),
+			Help:        "记录kafka消息消费成功的次数",
+			ConstLabels: labels,
+		}, []string{"topic", "bid"},
+	)
+	KafkaConsumeErrorCounter = promauto.NewCounterVec(
+		prometheus.CounterOpts{
+			Name:        prometheus.BuildFQName("cp", "kafka", "consume_error"),
+			Help:        "记录kafka消息消费失败的次数",
+			ConstLabels: labels,
+		}, []string{"topic", "bid"},
+	)
+	KafkaConsumeProcessingCounter = promauto.NewGaugeVec(prometheus.GaugeOpts{
+		Name:        prometheus.BuildFQName("cp", "kafka", "consume_processing"),
+		Help:        "当前正在处理的kafka消息个数",
+		ConstLabels: labels,
+	}, []string{"topic", "bid"},
+	)
+
+	requestInProgressTotal = promauto.NewGaugeVec(prometheus.GaugeOpts{
+		Name:        prometheus.BuildFQName("cp", "http", "requests_in_progress_total"),
+		Help:        "All the requests in progress",
+		ConstLabels: labels,
+	}, []string{"method"})
+
+	requestsTotal = promauto.NewCounterVec(prometheus.CounterOpts{
+		Name:        prometheus.BuildFQName("cp", "http", "requests_total"),
+		Help:        "Count all http requests by status code, method and path.",
+		ConstLabels: labels,
+	},
+		[]string{"status_code", "method", "path"},
+	)
+	requestDuration = promauto.NewHistogramVec(prometheus.HistogramOpts{
+		Name:        prometheus.BuildFQName("cp", "http", "request_duration_seconds"),
+		Help:        "Duration of all HTTP requests by status code, method and path.",
+		ConstLabels: labels,
+		Buckets: []float64{
+			0.000000001, // 1ns
+			0.000000002,
+			0.000000005,
+			0.00000001, // 10ns
+			0.00000002,
+			0.00000005,
+			0.0000001, // 100ns
+			0.0000002,
+			0.0000005,
+			0.000001, // 1µs
+			0.000002,
+			0.000005,
+			0.00001, // 10µs
+			0.00002,
+			0.00005,
+			0.0001, // 100µs
+			0.0002,
+			0.0005,
+			0.001, // 1ms
+			0.002,
+			0.005,
+			0.01, // 10ms
+			0.02,
+			0.05,
+			0.1, // 100 ms
+			0.2,
+			0.5,
+			1.0, // 1s
+			2.0,
+			5.0,
+			10.0, // 10s
+			15.0,
+			20.0,
+			30.0,
+		},
+	},
+		[]string{"status_code", "method", "path"},
+	)
+)
+
+func NewMiddleware(cfgs ...Config) fiber.Handler {
+	cfg := configDefault(cfgs...)
+	return func(ctx *fiber.Ctx) error {
+		if cfg.Next != nil && cfg.Next(ctx) {
+			return ctx.Next()
+		}
+		start := time.Now()
+		method := ctx.Route().Method
+
+		if ctx.Route().Path == "/metrics" {
+			return ctx.Next()
+		}
+
+		requestInProgressTotal.WithLabelValues(method).Inc()
+		defer requestInProgressTotal.WithLabelValues(method).Dec()
+
+		err := ctx.Next()
+		// initialize with default error code
+		// https://docs.gofiber.io/guide/error-handling
+		status := fiber.StatusInternalServerError
+		if err != nil {
+			if e, ok := err.(*fiber.Error); ok {
+				// Get correct error code from fiber.Error type
+				status = e.Code
+			}
+		} else {
+			status = ctx.Response().StatusCode()
+		}
+
+		path := ctx.Route().Path
+
+		statusCode := strconv.Itoa(status)
+		requestsTotal.WithLabelValues(statusCode, method, path).Inc()
+
+		elapsed := float64(time.Since(start).Nanoseconds()) / 1e9
+		requestDuration.WithLabelValues(statusCode, method, path).Observe(elapsed)
+
+		return err
+	}
+}