73 lines
2.1 KiB
Go
73 lines
2.1 KiB
Go
// Copyright 2020 by the contributors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package healthcheck
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import (
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"net/http"
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"github.com/prometheus/client_golang/prometheus"
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)
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type metricsHandler struct {
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handler Handler
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registry prometheus.Registerer
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}
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// NewMetricsHandler returns a healthy Handler that writes the current check status
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// into the provided Prometheus registry.
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func NewMetricsHandler(handler Handler, registry prometheus.Registerer) Handler {
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return &metricsHandler{
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handler: handler,
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registry: registry,
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}
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}
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func (h *metricsHandler) AddLivenessCheck(name string, check Check) {
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h.handler.AddLivenessCheck(name, h.wrap(prometheus.Labels{"name": name, "check": "live"}, check))
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}
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func (h *metricsHandler) AddReadinessCheck(name string, check Check) {
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h.handler.AddReadinessCheck(name, h.wrap(prometheus.Labels{"name": name, "check": "ready"}, check))
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}
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func (h *metricsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
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h.handler.ServeHTTP(w, r)
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}
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func (h *metricsHandler) LiveEndpoint(w http.ResponseWriter, r *http.Request) {
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h.handler.LiveEndpoint(w, r)
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}
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func (h *metricsHandler) ReadyEndpoint(w http.ResponseWriter, r *http.Request) {
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h.handler.ReadyEndpoint(w, r)
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}
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func (h *metricsHandler) wrap(labels prometheus.Labels, check Check) Check {
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h.registry.MustRegister(prometheus.NewGaugeFunc(
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prometheus.GaugeOpts{
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Name: "healthcheck",
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Help: "Indicates if check is healthy (1 is healthy, 0 is unhealthy)",
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ConstLabels: labels,
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},
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func() float64 {
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if check() != nil {
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return 0
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}
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return 1
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},
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))
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return check
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}
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