Node_Exporter/collector/netdev_linux.go
Noam Meltzer 501ccf9fb4 Add --collector.netdev.device-whitelist flag (#1279)
* Add --collector.netdev.device-whitelist flag

Sometimes it is desired to monitor only one netdev. The golang regexp
does not support a negated regex, so the ignored-devices flag is too
cumbersome for this task.
This change introduces a new flag: accept-devices, which is mutually
exclusive to ignored-devices. This flag allows specifying ONLY the
netdev you'd like.

Signed-off-by: Noam Meltzer <noam@cynerio.co>
2019-05-31 17:55:50 +02:00

92 lines
2.6 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 !nonetdev
package collector
import (
"bufio"
"fmt"
"io"
"os"
"regexp"
"strings"
"github.com/prometheus/common/log"
)
var (
procNetDevInterfaceRE = regexp.MustCompile(`^(.+): *(.+)$`)
procNetDevFieldSep = regexp.MustCompile(` +`)
)
func getNetDevStats(ignore *regexp.Regexp, accept *regexp.Regexp) (map[string]map[string]string, error) {
file, err := os.Open(procFilePath("net/dev"))
if err != nil {
return nil, err
}
defer file.Close()
return parseNetDevStats(file, ignore, accept)
}
func parseNetDevStats(r io.Reader, ignore *regexp.Regexp, accept *regexp.Regexp) (map[string]map[string]string, error) {
scanner := bufio.NewScanner(r)
scanner.Scan() // skip first header
scanner.Scan()
parts := strings.Split(scanner.Text(), "|")
if len(parts) != 3 { // interface + receive + transmit
return nil, fmt.Errorf("invalid header line in net/dev: %s",
scanner.Text())
}
receiveHeader := strings.Fields(parts[1])
transmitHeader := strings.Fields(parts[2])
headerLength := len(receiveHeader) + len(transmitHeader)
netDev := map[string]map[string]string{}
for scanner.Scan() {
line := strings.TrimLeft(scanner.Text(), " ")
parts := procNetDevInterfaceRE.FindStringSubmatch(line)
if len(parts) != 3 {
return nil, fmt.Errorf("couldn't get interface name, invalid line in net/dev: %q", line)
}
dev := parts[1]
if ignore != nil && ignore.MatchString(dev) {
log.Debugf("Ignoring device: %s", dev)
continue
}
if accept != nil && !accept.MatchString(dev) {
log.Debugf("Ignoring device: %s", dev)
continue
}
values := procNetDevFieldSep.Split(strings.TrimLeft(parts[2], " "), -1)
if len(values) != headerLength {
return nil, fmt.Errorf("couldn't get values, invalid line in net/dev: %q", parts[2])
}
netDev[dev] = map[string]string{}
for i := 0; i < len(receiveHeader); i++ {
netDev[dev]["receive_"+receiveHeader[i]] = values[i]
}
for i := 0; i < len(transmitHeader); i++ {
netDev[dev]["transmit_"+transmitHeader[i]] = values[i+len(receiveHeader)]
}
}
return netDev, scanner.Err()
}