aptly/api/middleware.go

104 lines
3.3 KiB
Go

package api
import (
"fmt"
"math"
"strconv"
"strings"
"time"
"github.com/gin-gonic/gin"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
)
var (
apiRequestsInFlightGauge = promauto.NewGaugeVec(
prometheus.GaugeOpts{
Name: "aptly_api_http_requests_in_flight",
Help: "Number of concurrent HTTP api requests currently handled.",
},
[]string{"method", "path"},
)
apiRequestsTotalCounter = promauto.NewCounterVec(
prometheus.CounterOpts{
Name: "aptly_api_http_requests_total",
Help: "Total number of api requests.",
},
[]string{"code", "method", "path"},
)
apiRequestSizeSummary = promauto.NewSummaryVec(
prometheus.SummaryOpts{
Name: "aptly_api_http_request_size_bytes",
Help: "Api HTTP request size in bytes.",
},
[]string{"code", "method", "path"},
)
apiResponseSizeSummary = promauto.NewSummaryVec(
prometheus.SummaryOpts{
Name: "aptly_api_http_response_size_bytes",
Help: "Api HTTP response size in bytes.",
},
[]string{"code", "method", "path"},
)
apiRequestsDurationSummary = promauto.NewSummaryVec(
prometheus.SummaryOpts{
Name: "aptly_api_http_request_duration_seconds",
Help: "Duration of api requests in seconds.",
},
[]string{"code", "method", "path"},
)
)
// Only use base path as label value (e.g.: /api/repos) because of time series cardinality
// See https://prometheus.io/docs/practices/naming/#labels
func getBasePath(c *gin.Context) string {
return fmt.Sprintf("%s%s", getURLSegment(c.Request.URL.Path, 0), getURLSegment(c.Request.URL.Path, 1))
}
func getURLSegment(url string, idx int) string {
var urlSegments = strings.Split(url, "/")
// Remove segment at index 0 because it's an empty string
var segmentAtIndex = urlSegments[1:cap(urlSegments)][idx]
return fmt.Sprintf("/%s", segmentAtIndex)
}
func instrumentHandlerInFlight(g *prometheus.GaugeVec, pathFunc func(*gin.Context) string) func(*gin.Context) {
return func(c *gin.Context) {
g.WithLabelValues(c.Request.Method, pathFunc(c)).Inc()
defer g.WithLabelValues(c.Request.Method, pathFunc(c)).Dec()
c.Next()
}
}
func instrumentHandlerCounter(counter *prometheus.CounterVec, pathFunc func(*gin.Context) string) func(*gin.Context) {
return func(c *gin.Context) {
c.Next()
counter.WithLabelValues(strconv.Itoa(c.Writer.Status()), c.Request.Method, pathFunc(c)).Inc()
}
}
func instrumentHandlerRequestSize(obs prometheus.ObserverVec, pathFunc func(*gin.Context) string) func(*gin.Context) {
return func(c *gin.Context) {
c.Next()
obs.WithLabelValues(strconv.Itoa(c.Writer.Status()), c.Request.Method, pathFunc(c)).Observe(float64(c.Request.ContentLength))
}
}
func instrumentHandlerResponseSize(obs prometheus.ObserverVec, pathFunc func(*gin.Context) string) func(*gin.Context) {
return func(c *gin.Context) {
c.Next()
var responseSize = math.Max(float64(c.Writer.Size()), 0)
obs.WithLabelValues(strconv.Itoa(c.Writer.Status()), c.Request.Method, pathFunc(c)).Observe(responseSize)
}
}
func instrumentHandlerDuration(obs prometheus.ObserverVec, pathFunc func(*gin.Context) string) func(*gin.Context) {
return func(c *gin.Context) {
now := time.Now()
c.Next()
obs.WithLabelValues(strconv.Itoa(c.Writer.Status()), c.Request.Method, pathFunc(c)).Observe(time.Since(now).Seconds())
}
}