rclone/fs/fshttp/prometheus.go
Michał Matczuk 38dc3e93ee fshttp: add prometheus metrics for HTTP status code
This patch adds rclone_http_status_code counter vector labeled by

* host,
* method,
* code.

It allows to see HTTP errors, backoffs etc.

The Metrics struct is designed for extensibility.
Adding new metrics is a matter of adding them to Metrics struct and including them in the response handling.

This feature has been discussed in the forum [1].

[1] https://forum.rclone.org/t/prometheus-metrics/14484
2021-11-17 18:38:12 +03:00

52 lines
1.1 KiB
Go

package fshttp
import (
"fmt"
"net/http"
"github.com/prometheus/client_golang/prometheus"
)
// Metrics provide Transport HTTP level metrics.
type Metrics struct {
StatusCode *prometheus.CounterVec
}
// NewMetrics creates a new metrics instance, the instance shall be assigned to
// DefaultMetrics before any processing takes place.
func NewMetrics(namespace string) *Metrics {
return &Metrics{
StatusCode: prometheus.NewCounterVec(prometheus.CounterOpts{
Namespace: namespace,
Subsystem: "http",
Name: "status_code",
}, []string{"host", "method", "code"}),
}
}
// DefaultMetrics specifies metrics used for new Transports.
var DefaultMetrics = (*Metrics)(nil)
// Collectors returns all prometheus metrics as collectors for registration.
func (m *Metrics) Collectors() []prometheus.Collector {
if m == nil {
return nil
}
return []prometheus.Collector{
m.StatusCode,
}
}
func (m *Metrics) onResponse(req *http.Request, resp *http.Response) {
if m == nil {
return
}
var statusCode = 0
if resp != nil {
statusCode = resp.StatusCode
}
m.StatusCode.WithLabelValues(req.Host, req.Method, fmt.Sprint(statusCode)).Inc()
}