snmp

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Version: v1.20.4 Latest Latest
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Published: Nov 17, 2021 License: MIT Imports: 19 Imported by: 160

README

SNMP Input Plugin

The snmp input plugin uses polling to gather metrics from SNMP agents. Support for gathering individual OIDs as well as complete SNMP tables is included.

Prerequisites

This plugin uses the snmptable and snmptranslate programs from the net-snmp project. These tools will need to be installed into the PATH in order to be located. Other utilities from the net-snmp project may be useful for troubleshooting, but are not directly used by the plugin.

These programs will load available MIBs on the system. Typically the default directory for MIBs is /usr/share/snmp/mibs, but if your MIBs are in a different location you may need to make the paths known to net-snmp. The location of these files can be configured in the snmp.conf or via the MIBDIRS environment variable. See man 1 snmpcmd for more information.

Configuration
[[inputs.snmp]]
  ## Agent addresses to retrieve values from.
  ##   format:  agents = ["<scheme://><hostname>:<port>"]
  ##   scheme:  optional, either udp, udp4, udp6, tcp, tcp4, tcp6.  
  ##            default is udp
  ##   port:    optional
  ##   example: agents = ["udp://127.0.0.1:161"]
  ##            agents = ["tcp://127.0.0.1:161"]
  ##            agents = ["udp4://v4only-snmp-agent"]
  agents = ["udp://127.0.0.1:161"]

  ## Timeout for each request.
  # timeout = "5s"

  ## SNMP version; can be 1, 2, or 3.
  # version = 2

  ## SNMP community string.
  # community = "public"

  ## Agent host tag
  # agent_host_tag = "agent_host"

  ## Number of retries to attempt.
  # retries = 3

  ## The GETBULK max-repetitions parameter.
  # max_repetitions = 10

  ## SNMPv3 authentication and encryption options.
  ##
  ## Security Name.
  # sec_name = "myuser"
  ## Authentication protocol; one of "MD5", "SHA", "SHA224", "SHA256", "SHA384", "SHA512" or "".
  # auth_protocol = "MD5"
  ## Authentication password.
  # auth_password = "pass"
  ## Security Level; one of "noAuthNoPriv", "authNoPriv", or "authPriv".
  # sec_level = "authNoPriv"
  ## Context Name.
  # context_name = ""
  ## Privacy protocol used for encrypted messages; one of "DES", "AES", "AES192", "AES192C", "AES256", "AES256C", or "".
  ### Protocols "AES192", "AES192", "AES256", and "AES256C" require the underlying net-snmp tools 
  ### to be compiled with --enable-blumenthal-aes (http://www.net-snmp.org/docs/INSTALL.html)
  # priv_protocol = ""
  ## Privacy password used for encrypted messages.
  # priv_password = ""

  ## Add fields and tables defining the variables you wish to collect.  This
  ## example collects the system uptime and interface variables.  Reference the
  ## full plugin documentation for configuration details.
  [[inputs.snmp.field]]
    oid = "RFC1213-MIB::sysUpTime.0"
    name = "uptime"

  [[inputs.snmp.field]]
    oid = "RFC1213-MIB::sysName.0"
    name = "source"
    is_tag = true

  [[inputs.snmp.table]]
    oid = "IF-MIB::ifTable"
    name = "interface"
    inherit_tags = ["source"]

    [[inputs.snmp.table.field]]
      oid = "IF-MIB::ifDescr"
      name = "ifDescr"
      is_tag = true
Configure SNMP Requests

This plugin provides two methods for configuring the SNMP requests: fields and tables. Use the field option to gather single ad-hoc variables. To collect SNMP tables, use the table option.

Field

Use a field to collect a variable by OID. Requests specified with this option operate similar to the snmpget utility.

[[inputs.snmp]]
  # ... snip ...

  [[inputs.snmp.field]]
    ## Object identifier of the variable as a numeric or textual OID.
    oid = "RFC1213-MIB::sysName.0"

    ## Name of the field or tag to create.  If not specified, it defaults to
    ## the value of 'oid'. If 'oid' is numeric, an attempt to translate the
    ## numeric OID into a textual OID will be made.
    # name = ""

    ## If true the variable will be added as a tag, otherwise a field will be
    ## created.
    # is_tag = false

    ## Apply one of the following conversions to the variable value:
    ##   float(X):    Convert the input value into a float and divides by the
    ##                Xth power of 10. Effectively just moves the decimal left
    ##                X places. For example a value of `123` with `float(2)`
    ##                will result in `1.23`.
    ##   float:       Convert the value into a float with no adjustment. Same
    ##                as `float(0)`.
    ##   int:         Convert the value into an integer.
    ##   hwaddr:      Convert the value to a MAC address.
    ##   ipaddr:      Convert the value to an IP address.
    ##   hextoint:X:Y Convert a hex string value to integer. Where X is the Endian
    ##                and Y the bit size. For example: hextoint:LittleEndian:uint64
    ##                or hextoint:BigEndian:uint32. Valid options for the Endian are:
    ##                BigEndian and LittleEndian. For the bit size: uint16, uint32
    ##                and uint64.
    ##                      
    # conversion = ""
Table

Use a table to configure the collection of a SNMP table. SNMP requests formed with this option operate similarly way to the snmptable command.

Control the handling of specific table columns using a nested field. These nested fields are specified similarly to a top-level field.

By default all columns of the SNMP table will be collected - it is not required to add a nested field for each column, only those which you wish to modify. To only collect certain columns, omit the oid from the table section and only include oid settings in field sections. For more complex include/exclude cases for columns use metric filtering.

One metric is created for each row of the SNMP table.

[[inputs.snmp]]
  # ... snip ...

  [[inputs.snmp.table]]
    ## Object identifier of the SNMP table as a numeric or textual OID.
    oid = "IF-MIB::ifTable"

    ## Name of the field or tag to create.  If not specified, it defaults to
    ## the value of 'oid'.  If 'oid' is numeric an attempt to translate the
    ## numeric OID into a textual OID will be made.
    # name = ""

    ## Which tags to inherit from the top-level config and to use in the output
    ## of this table's measurement.
    ## example: inherit_tags = ["source"]
    # inherit_tags = []

    ## Add an 'index' tag with the table row number.  Use this if the table has
    ## no indexes or if you are excluding them.  This option is normally not
    ## required as any index columns are automatically added as tags.
    # index_as_tag = false

    [[inputs.snmp.table.field]]
      ## OID to get. May be a numeric or textual module-qualified OID.
      oid = "IF-MIB::ifDescr"

      ## Name of the field or tag to create.  If not specified, it defaults to
      ## the value of 'oid'. If 'oid' is numeric an attempt to translate the
      ## numeric OID into a textual OID will be made.
      # name = ""

      ## Output this field as a tag.
      # is_tag = false

      ## The OID sub-identifier to strip off so that the index can be matched
      ## against other fields in the table.
      # oid_index_suffix = ""

      ## Specifies the length of the index after the supplied table OID (in OID
      ## path segments). Truncates the index after this point to remove non-fixed
      ## value or length index suffixes.
      # oid_index_length = 0

      ## Specifies if the value of given field should be snmptranslated
      ## by default no field values are translated
      # translate = true
Troubleshooting

Check that a numeric field can be translated to a textual field:

$ snmptranslate .1.3.6.1.2.1.1.3.0
DISMAN-EVENT-MIB::sysUpTimeInstance

Request a top-level field:

$ snmpget -v2c -c public 127.0.0.1 sysUpTime.0

Request a table:

$ snmptable -v2c -c public 127.0.0.1 ifTable

To collect a packet capture, run this command in the background while running Telegraf or one of the above commands. Adjust the interface, host and port as needed:

$ sudo tcpdump -s 0 -i eth0 -w telegraf-snmp.pcap host 127.0.0.1 and port 161
Example Output
snmp,agent_host=127.0.0.1,source=loaner uptime=11331974i 1575509815000000000
interface,agent_host=127.0.0.1,ifDescr=wlan0,ifIndex=3,source=example.org ifAdminStatus=1i,ifInDiscards=0i,ifInErrors=0i,ifInNUcastPkts=0i,ifInOctets=3436617431i,ifInUcastPkts=2717778i,ifInUnknownProtos=0i,ifLastChange=0i,ifMtu=1500i,ifOperStatus=1i,ifOutDiscards=0i,ifOutErrors=0i,ifOutNUcastPkts=0i,ifOutOctets=581368041i,ifOutQLen=0i,ifOutUcastPkts=1354338i,ifPhysAddress="c8:5b:76:c9:e6:8c",ifSpecific=".0.0",ifSpeed=0i,ifType=6i 1575509815000000000
interface,agent_host=127.0.0.1,ifDescr=eth0,ifIndex=2,source=example.org ifAdminStatus=1i,ifInDiscards=0i,ifInErrors=0i,ifInNUcastPkts=21i,ifInOctets=3852386380i,ifInUcastPkts=3634004i,ifInUnknownProtos=0i,ifLastChange=9088763i,ifMtu=1500i,ifOperStatus=1i,ifOutDiscards=0i,ifOutErrors=0i,ifOutNUcastPkts=0i,ifOutOctets=434865441i,ifOutQLen=0i,ifOutUcastPkts=2110394i,ifPhysAddress="c8:5b:76:c9:e6:8c",ifSpecific=".0.0",ifSpeed=1000000000i,ifType=6i 1575509815000000000
interface,agent_host=127.0.0.1,ifDescr=lo,ifIndex=1,source=example.org ifAdminStatus=1i,ifInDiscards=0i,ifInErrors=0i,ifInNUcastPkts=0i,ifInOctets=51555569i,ifInUcastPkts=339097i,ifInUnknownProtos=0i,ifLastChange=0i,ifMtu=65536i,ifOperStatus=1i,ifOutDiscards=0i,ifOutErrors=0i,ifOutNUcastPkts=0i,ifOutOctets=51555569i,ifOutQLen=0i,ifOutUcastPkts=339097i,ifSpecific=".0.0",ifSpeed=10000000i,ifType=24i 1575509815000000000

Documentation

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func SnmpTranslate added in v1.14.0

func SnmpTranslate(oid string) (mibName string, oidNum string, oidText string, conversion string, err error)

snmpTranslate resolves the given OID.

Types

type Field added in v1.14.0

type Field struct {
	// Name will be the name of the field.
	Name string
	// OID is prefix for this field. The plugin will perform a walk through all
	// OIDs with this as their parent. For each value found, the plugin will strip
	// off the OID prefix, and use the remainder as the index. For multiple fields
	// to show up in the same row, they must share the same index.
	Oid string
	// OidIndexSuffix is the trailing sub-identifier on a table record OID that will be stripped off to get the record's index.
	OidIndexSuffix string
	// OidIndexLength specifies the length of the index in OID path segments. It can be used to remove sub-identifiers that vary in content or length.
	OidIndexLength int
	// IsTag controls whether this OID is output as a tag or a value.
	IsTag bool
	// Conversion controls any type conversion that is done on the value.
	//  "float"/"float(0)" will convert the value into a float.
	//  "float(X)" will convert the value into a float, and then move the decimal before Xth right-most digit.
	//  "int" will conver the value into an integer.
	//  "hwaddr" will convert a 6-byte string to a MAC address.
	//  "ipaddr" will convert the value to an IPv4 or IPv6 address.
	Conversion string
	// Translate tells if the value of the field should be snmptranslated
	Translate bool
	// contains filtered or unexported fields
}

Field holds the configuration for a Field to look up.

type RTable added in v1.14.0

type RTable struct {
	// Name is the name of the field, copied from Table.Name.
	Name string
	// Time is the time the table was built.
	Time time.Time
	// Rows are the rows that were found, one row for each table OID index found.
	Rows []RTableRow
}

RTable is the resulting table built from a Table.

type RTableRow added in v1.14.0

type RTableRow struct {
	// Tags are all the Field values which had IsTag=true.
	Tags map[string]string
	// Fields are all the Field values which had IsTag=false.
	Fields map[string]interface{}
}

RTableRow is the resulting row containing all the OID values which shared the same index.

type Snmp

type Snmp struct {
	// The SNMP agent to query. Format is [SCHEME://]ADDR[:PORT] (e.g.
	// udp://1.2.3.4:161).  If the scheme is not specified then "udp" is used.
	Agents []string `toml:"agents"`

	// The tag used to name the agent host
	AgentHostTag string `toml:"agent_host_tag"`

	snmp.ClientConfig

	Tables []Table `toml:"table"`

	// Name & Fields are the elements of a Table.
	// Telegraf chokes if we try to embed a Table. So instead we have to embed the
	// fields of a Table, and construct a Table during runtime.
	Name   string  // deprecated in 1.14; use name_override
	Fields []Field `toml:"field"`
	// contains filtered or unexported fields
}

Snmp holds the configuration for the plugin.

func (*Snmp) Description

func (s *Snmp) Description() string

Description returns a one-sentence description on the input.

func (*Snmp) Gather

func (s *Snmp) Gather(acc telegraf.Accumulator) error

Gather retrieves all the configured fields and tables. Any error encountered does not halt the process. The errors are accumulated and returned at the end.

func (*Snmp) SampleConfig

func (s *Snmp) SampleConfig() string

SampleConfig returns the default configuration of the input.

type Table added in v1.14.0

type Table struct {
	// Name will be the name of the measurement.
	Name string

	// Which tags to inherit from the top-level config.
	InheritTags []string

	// Adds each row's table index as a tag.
	IndexAsTag bool

	// Fields is the tags and values to look up.
	Fields []Field `toml:"field"`

	// OID for automatic field population.
	// If provided, init() will populate Fields with all the table columns of the
	// given OID.
	Oid string
	// contains filtered or unexported fields
}

Table holds the configuration for a SNMP table.

func (Table) Build added in v1.14.0

func (t Table) Build(gs snmpConnection, walk bool) (*RTable, error)

Build retrieves all the fields specified in the table and constructs the RTable.

func (*Table) Init added in v1.15.0

func (t *Table) Init() error

Init() builds & initializes the nested fields.

Source Files

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