telegraf/plugins/inputs/snmp/snmp.go

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package snmp
import (
"io/ioutil"
"log"
"net"
"regexp"
"strconv"
"strings"
"time"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/plugins/inputs"
"github.com/soniah/gosnmp"
)
// Snmp is a snmp plugin
type Snmp struct {
Host []Host
Get []Data
Bulk []Data
SnmptranslateFile string
}
type Host struct {
Address string
Community string
// SNMP version. Default 2
Version int
// SNMP timeout, in seconds. 0 means no timeout
Timeout float64
// SNMP retries
Retries int
// Data to collect (list of Data names)
Collect []string
// easy get oids
GetOids []string
// Oids
getOids []Data
bulkOids []Data
}
type Data struct {
Name string
// OID (could be numbers or name)
Oid string
// Unit
Unit string
// SNMP getbulk max repetition
MaxRepetition uint8 `toml:"max_repetition"`
// SNMP Instance (default 0)
// (only used with GET request and if
// OID is a name from snmptranslate file)
Instance string
// OID (only number) (used for computation)
rawOid string
}
type Node struct {
id string
name string
subnodes map[string]Node
}
var initNode = Node{
id: "1",
name: "",
subnodes: make(map[string]Node),
}
var NameToOid = make(map[string]string)
var sampleConfig = `
### Use 'oids.txt' file to translate oids to names
### To generate 'oids.txt' you need to run:
### snmptranslate -m all -Tz -On | sed -e 's/"//g' > /tmp/oids.txt
### Or if you have an other MIB folder with custom MIBs
### snmptranslate -M /mycustommibfolder -Tz -On -m all | sed -e 's/"//g' > oids.txt
snmptranslate_file = "/tmp/oids.txt"
[[inputs.snmp.host]]
address = "192.168.2.2:161"
# SNMP community
community = "public" # default public
# SNMP version (1, 2 or 3)
# Version 3 not supported yet
version = 2 # default 2
# SNMP response timeout
timeout = 2.0 # default 2.0
# SNMP request retries
retries = 2 # default 2
# Which get/bulk do you want to collect for this host
collect = ["mybulk", "sysservices", "sysdescr"]
# Simple list of OIDs to get, in addition to "collect"
get_oids = []
[[inputs.snmp.host]]
address = "192.168.2.3:161"
community = "public"
version = 2
timeout = 2.0
retries = 2
collect = ["mybulk"]
get_oids = [
"ifNumber",
".1.3.6.1.2.1.1.3.0",
]
[[inputs.snmp.get]]
name = "ifnumber"
oid = "ifNumber"
[[inputs.snmp.get]]
name = "interface_speed"
oid = "ifSpeed"
instance = 0
[[inputs.snmp.get]]
name = "sysuptime"
oid = ".1.3.6.1.2.1.1.3.0"
unit = "second"
[[inputs.snmp.bulk]]
name = "mybulk"
max_repetition = 127
oid = ".1.3.6.1.2.1.1"
[[inputs.snmp.bulk]]
name = "ifoutoctets"
max_repetition = 127
oid = "ifOutOctets"
`
// SampleConfig returns sample configuration message
func (s *Snmp) SampleConfig() string {
return sampleConfig
}
// Description returns description of Zookeeper plugin
func (s *Snmp) Description() string {
return `Reads oids value from one or many snmp agents`
}
func fillnode(parentNode Node, oid_name string, ids []string) {
// ids = ["1", "3", "6", ...]
id, ids := ids[0], ids[1:]
node, ok := parentNode.subnodes[id]
if ok == false {
node = Node{
id: id,
name: "",
subnodes: make(map[string]Node),
}
if len(ids) == 0 {
node.name = oid_name
}
parentNode.subnodes[id] = node
}
if len(ids) > 0 {
fillnode(node, oid_name, ids)
}
}
func findnodename(node Node, ids []string) (string, string) {
// ids = ["1", "3", "6", ...]
if len(ids) == 1 {
return node.name, ids[0]
}
id, ids := ids[0], ids[1:]
// Get node
subnode, ok := node.subnodes[id]
if ok {
return findnodename(subnode, ids)
}
// We got a node
// Get node name
if node.name != "" && len(ids) == 0 && id == "0" {
// node with instance 0
return node.name, "0"
} else if node.name != "" && len(ids) == 0 && id != "0" {
// node with an instance
return node.name, string(id)
} else if node.name != "" && len(ids) > 0 {
// node with subinstances
return node.name, strings.Join(ids, ".")
}
// return an empty node name
return node.name, ""
}
func (s *Snmp) Gather(acc telegraf.Accumulator) error {
// Create oid tree
if s.SnmptranslateFile != "" && len(initNode.subnodes) == 0 {
data, err := ioutil.ReadFile(s.SnmptranslateFile)
if err != nil {
log.Printf("Reading SNMPtranslate file error: %s", err)
return err
} else {
for _, line := range strings.Split(string(data), "\n") {
oidsRegEx := regexp.MustCompile(`([^\t]*)\t*([^\t]*)`)
oids := oidsRegEx.FindStringSubmatch(string(line))
if oids[2] != "" {
oid_name := oids[1]
oid := oids[2]
fillnode(initNode, oid_name, strings.Split(string(oid), "."))
NameToOid[oid_name] = oid
}
}
}
}
// Fetching data
for _, host := range s.Host {
// Set default args
if len(host.Address) == 0 {
host.Address = "127.0.0.1:161"
}
if host.Community == "" {
host.Community = "public"
}
if host.Timeout <= 0 {
host.Timeout = 2.0
}
if host.Retries <= 0 {
host.Retries = 2
}
// Prepare host
// Get Easy GET oids
for _, oidstring := range host.GetOids {
oid := Data{}
if val, ok := NameToOid[oidstring]; ok {
// TODO should we add the 0 instance ?
oid.Name = oidstring
oid.Oid = val
oid.rawOid = "." + val + ".0"
} else {
oid.Name = oidstring
oid.Oid = oidstring
if string(oidstring[:1]) != "." {
oid.rawOid = "." + oidstring
} else {
oid.rawOid = oidstring
}
}
host.getOids = append(host.getOids, oid)
}
for _, oid_name := range host.Collect {
// Get GET oids
for _, oid := range s.Get {
if oid.Name == oid_name {
if val, ok := NameToOid[oid.Oid]; ok {
// TODO should we add the 0 instance ?
if oid.Instance != "" {
oid.rawOid = "." + val + "." + oid.Instance
} else {
oid.rawOid = "." + val + ".0"
}
} else {
oid.rawOid = oid.Oid
}
host.getOids = append(host.getOids, oid)
}
}
// Get GETBULK oids
for _, oid := range s.Bulk {
if oid.Name == oid_name {
if val, ok := NameToOid[oid.Oid]; ok {
oid.rawOid = "." + val
} else {
oid.rawOid = oid.Oid
}
host.bulkOids = append(host.bulkOids, oid)
}
}
}
// Launch Get requests
if err := host.SNMPGet(acc); err != nil {
return err
}
if err := host.SNMPBulk(acc); err != nil {
return err
}
}
return nil
}
func (h *Host) SNMPGet(acc telegraf.Accumulator) error {
// Get snmp client
snmpClient, err := h.GetSNMPClient()
if err != nil {
return err
}
// Deconnection
defer snmpClient.Conn.Close()
// Prepare OIDs
oidsList := make(map[string]Data)
for _, oid := range h.getOids {
oidsList[oid.rawOid] = oid
}
oidsNameList := make([]string, 0, len(oidsList))
for _, oid := range oidsList {
oidsNameList = append(oidsNameList, oid.rawOid)
}
// gosnmp.MAX_OIDS == 60
// TODO use gosnmp.MAX_OIDS instead of hard coded value
max_oids := 60
// limit 60 (MAX_OIDS) oids by requests
for i := 0; i < len(oidsList); i = i + max_oids {
// Launch request
max_index := i + max_oids
if i+max_oids > len(oidsList) {
max_index = len(oidsList)
}
result, err3 := snmpClient.Get(oidsNameList[i:max_index]) // Get() accepts up to g.MAX_OIDS
if err3 != nil {
return err3
}
// Handle response
_, err = h.HandleResponse(oidsList, result, acc)
if err != nil {
return err
}
}
return nil
}
func (h *Host) SNMPBulk(acc telegraf.Accumulator) error {
// Get snmp client
snmpClient, err := h.GetSNMPClient()
if err != nil {
return err
}
// Deconnection
defer snmpClient.Conn.Close()
// Prepare OIDs
oidsList := make(map[string]Data)
for _, oid := range h.bulkOids {
oidsList[oid.rawOid] = oid
}
oidsNameList := make([]string, 0, len(oidsList))
for _, oid := range oidsList {
oidsNameList = append(oidsNameList, oid.rawOid)
}
// TODO Trying to make requests with more than one OID
// to reduce the number of requests
for _, oid := range oidsNameList {
oid_asked := oid
need_more_requests := true
// Set max repetition
maxRepetition := oidsList[oid].MaxRepetition
if maxRepetition <= 0 {
maxRepetition = 32
}
// Launch requests
for need_more_requests {
// Launch request
result, err3 := snmpClient.GetBulk([]string{oid}, 0, maxRepetition)
if err3 != nil {
return err3
}
// Handle response
last_oid, err := h.HandleResponse(oidsList, result, acc)
if err != nil {
return err
}
// Determine if we need more requests
if strings.HasPrefix(last_oid, oid_asked) {
need_more_requests = true
oid = last_oid
} else {
need_more_requests = false
}
}
}
return nil
}
func (h *Host) GetSNMPClient() (*gosnmp.GoSNMP, error) {
// Prepare Version
var version gosnmp.SnmpVersion
if h.Version == 1 {
version = gosnmp.Version1
} else if h.Version == 3 {
version = gosnmp.Version3
} else {
version = gosnmp.Version2c
}
// Prepare host and port
host, port_str, err := net.SplitHostPort(h.Address)
if err != nil {
port_str = string("161")
}
// convert port_str to port in uint16
port_64, err := strconv.ParseUint(port_str, 10, 16)
port := uint16(port_64)
// Get SNMP client
snmpClient := &gosnmp.GoSNMP{
Target: host,
Port: port,
Community: h.Community,
Version: version,
Timeout: time.Duration(h.Timeout) * time.Second,
Retries: h.Retries,
}
// Connection
err2 := snmpClient.Connect()
if err2 != nil {
return nil, err2
}
// Return snmpClient
return snmpClient, nil
}
func (h *Host) HandleResponse(oids map[string]Data, result *gosnmp.SnmpPacket, acc telegraf.Accumulator) (string, error) {
var lastOid string
for _, variable := range result.Variables {
lastOid = variable.Name
// Remove unwanted oid
for oid_key, oid := range oids {
if strings.HasPrefix(variable.Name, oid_key) {
switch variable.Type {
// handle Metrics
case gosnmp.Boolean, gosnmp.Integer, gosnmp.Counter32, gosnmp.Gauge32,
gosnmp.TimeTicks, gosnmp.Counter64, gosnmp.Uinteger32:
// Prepare tags
tags := make(map[string]string)
if oid.Unit != "" {
tags["unit"] = oid.Unit
}
// Get name and instance
var oid_name string
var instance string
// Get oidname and instannce from translate file
oid_name, instance = findnodename(initNode,
strings.Split(string(variable.Name[1:]), "."))
if instance != "" {
tags["instance"] = instance
}
// Set name
var field_name string
if oid_name != "" {
// Set fieldname as oid name from translate file
field_name = oid_name
} else {
// Set fieldname as oid name from inputs.snmp.get section
// Because the result oid is equal to inputs.snmp.get section
field_name = oid.Name
}
tags["host"], _, _ = net.SplitHostPort(h.Address)
fields := make(map[string]interface{})
fields[string(field_name)] = variable.Value
acc.AddFields(field_name, fields, tags)
case gosnmp.NoSuchObject, gosnmp.NoSuchInstance:
// Oid not found
log.Printf("[snmp input] Oid not found: %s", oid_key)
default:
// delete other data
}
break
}
}
}
return lastOid, nil
}
func init() {
inputs.Add("snmp", func() telegraf.Input {
return &Snmp{}
})
}