mirror of https://github.com/prometheus/prometheus
73 lines
2.4 KiB
Go
73 lines
2.4 KiB
Go
// Copyright 2020 The Prometheus 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 discovery
|
|
|
|
import (
|
|
"fmt"
|
|
|
|
"github.com/prometheus/client_golang/prometheus"
|
|
)
|
|
|
|
// MetricRegisterer is used by implementations of discovery.Discoverer that need
|
|
// to manage the lifetime of their metrics.
|
|
type MetricRegisterer interface {
|
|
RegisterMetrics() error
|
|
UnregisterMetrics()
|
|
}
|
|
|
|
// metricRegistererImpl is an implementation of MetricRegisterer.
|
|
type metricRegistererImpl struct {
|
|
reg prometheus.Registerer
|
|
metrics []prometheus.Collector
|
|
}
|
|
|
|
var _ MetricRegisterer = &metricRegistererImpl{}
|
|
|
|
// NewMetricRegisterer creates an instance of a MetricRegisterer.
|
|
// Typically called inside the implementation of the NewDiscoverer() method.
|
|
func NewMetricRegisterer(reg prometheus.Registerer, metrics []prometheus.Collector) MetricRegisterer {
|
|
return &metricRegistererImpl{
|
|
reg: reg,
|
|
metrics: metrics,
|
|
}
|
|
}
|
|
|
|
// RegisterMetrics registers the metrics with a Prometheus registerer.
|
|
// If any metric fails to register, it will unregister all metrics that
|
|
// were registered so far, and return an error.
|
|
// Typically called at the start of the SD's Run() method.
|
|
func (rh *metricRegistererImpl) RegisterMetrics() error {
|
|
for _, collector := range rh.metrics {
|
|
err := rh.reg.Register(collector)
|
|
if err != nil {
|
|
// Unregister all metrics that were registered so far.
|
|
// This is so that if RegisterMetrics() gets called again,
|
|
// there will not be an error due to a duplicate registration.
|
|
rh.UnregisterMetrics()
|
|
|
|
return fmt.Errorf("failed to register metric: %w", err)
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// UnregisterMetrics unregisters the metrics from the same Prometheus
|
|
// registerer which was used to register them.
|
|
// Typically called at the end of the SD's Run() method by a defer statement.
|
|
func (rh *metricRegistererImpl) UnregisterMetrics() {
|
|
for _, collector := range rh.metrics {
|
|
rh.reg.Unregister(collector)
|
|
}
|
|
}
|