node_exporter/collector/entropy_linux.go
Ben Kochie dfa53f835a
Use Go 1.13 error features
* Use `errors.Is()` for unwrapping errors.
* Use `%w` error verb in internal error formatting.

Signed-off-by: Ben Kochie <superq@gmail.com>
2020-06-16 14:47:03 +02:00

56 lines
1.6 KiB
Go

// Copyright 2015 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.
// +build !noentropy
package collector
import (
"fmt"
"github.com/go-kit/kit/log"
"github.com/prometheus/client_golang/prometheus"
)
type entropyCollector struct {
entropyAvail *prometheus.Desc
logger log.Logger
}
func init() {
registerCollector("entropy", defaultEnabled, NewEntropyCollector)
}
// NewEntropyCollector returns a new Collector exposing entropy stats.
func NewEntropyCollector(logger log.Logger) (Collector, error) {
return &entropyCollector{
entropyAvail: prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "entropy_available_bits"),
"Bits of available entropy.",
nil, nil,
),
logger: logger,
}, nil
}
func (c *entropyCollector) Update(ch chan<- prometheus.Metric) error {
value, err := readUintFromFile(procFilePath("sys/kernel/random/entropy_avail"))
if err != nil {
return fmt.Errorf("couldn't get entropy_avail: %w", err)
}
ch <- prometheus.MustNewConstMetric(
c.entropyAvail, prometheus.GaugeValue, float64(value))
return nil
}