gin-metrics
gin-gonic/gin metrics exporter for Prometheus.
Introduction
gin-metrics defines some metrics for gin http-server. There have easy way to use it.
Below is the detailed description for every metric.
| Metric | Type | Description |
|---|---|---|
| gin_request_total | Counter | all the server received request num. |
| gin_request_uv | Counter | all the server received ip num. |
| gin_uri_request_total | Counter | all the server received request num with every uri. |
| gin_request_body_total | Counter | the server received request body size, unit byte. |
| gin_response_body_total | Counter | the server send response body size, unit byte. |
| gin_request_duration | Histogram | the time server took to handle the request. |
| gin_slow_request_total | Counter | the server handled slow requests counter, t=%d. |
Grafana
Set the grafana directory for details.
Installation
$ go get github.com/penglongli/gin-metricsUsage
Your can see some metrics across http://localhost:8080/metrics
package main
import (
"github.com/gin-gonic/gin"
"github.com/penglongli/gin-metrics/ginmetrics"
)
func main() {
r := gin.Default()
// get global Monitor object
m := ginmetrics.GetMonitor()
// +optional set metric path, default /debug/metrics
m.SetMetricPath("/metrics")
// +optional set slow time, default 5s
m.SetSlowTime(10)
// +optional set request duration, default {0.1, 0.3, 1.2, 5, 10}
// used to p95, p99
m.SetDuration([]float64{0.1, 0.3, 1.2, 5, 10})
// set middleware for gin
m.Use(r)
r.GET("/product/:id", func(ctx *gin.Context) {
ctx.JSON(200, map[string]string{
"productId": ctx.Param("id"),
})
})
_ = r.Run()
}Custom Metric
gin-metric provides ways to custom your own metric.
Gauge
With Gauge type metric, you can use three functions to change it's value.
And you should define a Gauge Metric first,
gaugeMetric := &ginmetrics.Metric{
Type: ginmetrics.Gauge,
Name: "example_gauge_metric",
Description: "an example of gauge type metric",
Labels: []string{"label1"},
}
// Add metric to global monitor object
_ = ginmetrics.GetMonitor().AddMetric(gaugeMetric)SetGaugeValue
SetGaugeValue will setting metric value directly。
_ = ginmetrics.GetMonitor().GetMetric("example_gauge_metric").SetGaugeValue([]string{"label_value1"}, 0.1)Inc
Inc will increase 1 to metric value
_ = ginmetrics.GetMonitor().GetMetric("example_gauge_metric").Inc([]string{"label_value1"})Add
Add will add float64 num to metric value
_ = ginmetrics.GetMonitor().GetMetric("example_gauge_metric").Add([]string{"label_value1"}, 0.2)Counter
With Counter type metric, you can use Inc and Add function, don't use SetGaugeValue.
Histogram and Summary
For Histogram and Summary type metric, should use Observe function.
Metric with separate port
For some users, they don't want to merge the port of the metric with the port of the application.
So we provide a way to separate the metric port. Here is the example.
func main() {
appRouter := gin.Default()
metricRouter := gin.Default()
m := ginmetrics.GetMonitor()
// use metric middleware without expose metric path
m.UseWithoutExposingEndpoint(appRouter)
// set metric path expose to metric router
m.Expose(metricRouter)
appRouter.GET("/product/:id", func(ctx *gin.Context) {
ctx.JSON(200, map[string]string{
"productId": ctx.Param("id"),
})
})
go func() {
_ = metricRouter.Run(":8081")
}()
_ = appRouter.Run(":8080")
}Contributing
If someone has a problem or suggestions, you can submit new issues or new pull requests.