// Copyright 2019 The Operator-SDK Authors
//
// 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 kubemetrics
import (
"fmt"
"net"
"net/http"
kcollector "k8s.io/kube-state-metrics/pkg/collector"
)
const (
metricsPath = "/metrics"
healthzPath = "/healthz"
)
func ServeMetrics(collectors [][]kcollector.Collector, host string, port int32) {
listenAddress := net.JoinHostPort(host, fmt.Sprint(port))
mux := http.NewServeMux()
// Add metricsPath
mux.Handle(metricsPath, &metricHandler{collectors})
// Add healthzPath
mux.HandleFunc(healthzPath, func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(200)
w.Write([]byte("ok"))
})
// Add index
mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte(`
Operator SDK Metrics
kube-metrics
`))
})
err := http.ListenAndServe(listenAddress, mux)
log.Error(err, "Failed to serve custom metrics")
}
type metricHandler struct {
collectors [][]kcollector.Collector
}
func (m *metricHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
resHeader := w.Header()
// 0.0.4 is the exposition format version of prometheus
// https://prometheus.io/docs/instrumenting/exposition_formats/#text-based-format
resHeader.Set("Content-Type", `text/plain; version=`+"0.0.4")
for _, collectors := range m.collectors {
for _, c := range collectors {
c.Collect(w)
}
}
}