（GitHub） telegraf snmp input plugin README

说明

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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.

Note about Paths

Path is a global variable, separate snmp instances will append the specified path onto the global path variable

Global configuration options

In addition to the plugin-specific configuration settings, plugins support additional global and plugin configuration settings. These settings are used to modify metrics, tags, and field or create aliases and configure ordering, etc. See the CONFIGURATION.md CONFIGURATION.md] for more details.

SNMP backend: gosmi and netsnmp

Telegraf has two backends to translate SNMP objects. By default, Telegraf will use netsnmp, however, this option is deprecated and it is encouraged that users migrate to gosmi. If users find issues with gosmi that do not occur with netsnmp please open a project issue on GitHub.

The SNMP backend setting is a global-level setting that applies to all use of SNMP in Telegraf. Users can set this option in the [agent] configuration via the snmp_translator option. See the agent configuration for more details.

Configuration

# Retrieves SNMP values from remote agents
[[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

  ## Unconnected UDP socket
  ## When true, SNMP responses are accepted from any address not just
  ## the requested address. This can be useful when gathering from
  ## redundant/failover systems.
  # unconnected_udp_socket = false

  ## Path to mib files
  ## Used by the gosmi translator.
  ## To add paths when translating with netsnmp, use the MIBDIRS environment variable
  # path = ["/usr/share/snmp/mibs"]

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

  ## Agent host tag; should be set to "source" for consistent usage across plugins
  ##   example: agent_host_tag = "source"
  ## The default value is inconsistent with other plugins. Users will get a
  ## warning that can be ignored if this is not changed. However, to have a
  ## consistent experience, set this to "source" in your config to align with
  ## other plugins.
  # 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 = "sysUptime"
    conversion = "float(2)"

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

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

    [[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.
    ##   enum(1):     Convert the value according to its syntax in the MIB (full).
    ##                (Only supported with gosmi translator)
    ##   enum:        Convert the value according to its syntax in the MIB.
    ##                (Only supported with gosmi translator)
    ##
    # 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

      ## Secondary index table allows to merge data from two tables with
      ## different index that this filed will be used to join them. There can
      ## be only one secondary index table.
      # secondary_index_table = false

      ## This field is using secondary index, and will be later merged with
      ## primary index using SecondaryIndexTable. SecondaryIndexTable and
      ## SecondaryIndexUse are exclusive.
      # secondary_index_use = false

      ## Controls if entries from secondary table should be added or not
      ## if joining index is present or not. I set to true, means that join
      ## is outer, and index is prepended with "Secondary." for missing values
      ## to avoid overlapping indexes from both tables. Can be set per field or
      ## globally with SecondaryIndexTable, global true overrides per field false.
      # secondary_outer_join = false

Two Table Join

Snmp plugin can join two snmp tables that have different indexes. For this to work one table should have translation field that return index of second table as value. Examples of such fields are:

• Cisco portTable with translation field: CISCO-STACK-MIB::portIfIndex, which value is IfIndex from ifTable
• Adva entityFacilityTable with translation field: ADVA-FSPR7-MIB::entityFacilityOneIndex, which value is IfIndex from ifTable
• Cisco cpeExtPsePortTable with translation field: CISCO-POWER-ETHERNET-EXT-MIB::cpeExtPsePortEntPhyIndex, which value is index from entPhysicalTable

Such field can be used to translate index to secondary table with secondary_index_table = true and all fields from secondary table (with index pointed from translation field), should have added option secondary_index_use = true. Telegraf cannot duplicate entries during join so translation must be 1-to-1 (not 1-to-many). To add fields from secondary table with index that is not present in translation table (outer join), there is a second option for translation index secondary_outer_join = true.

Example configuration for table joins

CISCO-POWER-ETHERNET-EXT-MIB table before join:

[[inputs.snmp.table]]
name = "ciscoPower"
index_as_tag = true

[[inputs.snmp.table.field]]
name = "PortPwrConsumption"
oid = "CISCO-POWER-ETHERNET-EXT-MIB::cpeExtPsePortPwrConsumption"

[[inputs.snmp.table.field]]
name = "EntPhyIndex"
oid = "CISCO-POWER-ETHERNET-EXT-MIB::cpeExtPsePortEntPhyIndex"

Partial result (removed agent and host tags from all following outputs in this section):

> ciscoPower,index=1.2 EntPhyIndex=1002i,PortPwrConsumption=6643i 1621460628000000000
> ciscoPower,index=1.6 EntPhyIndex=1006i,PortPwrConsumption=10287i 1621460628000000000
> ciscoPower,index=1.5 EntPhyIndex=1005i,PortPwrConsumption=8358i 1621460628000000000

Note here that EntPhyIndex column carries index from ENTITY-MIB table, config for it:

[[inputs.snmp.table]]
name = "entityTable"
index_as_tag = true

[[inputs.snmp.table.field]]
name = "EntPhysicalName"
oid = "ENTITY-MIB::entPhysicalName"

Partial result:

> entityTable,index=1006 EntPhysicalName="GigabitEthernet1/6" 1621460809000000000
> entityTable,index=1002 EntPhysicalName="GigabitEthernet1/2" 1621460809000000000
> entityTable,index=1005 EntPhysicalName="GigabitEthernet1/5" 1621460809000000000

Now, lets attempt to join these results into one table. EntPhyIndex matches index from second table, and lets convert EntPhysicalName into tag, so second table will only provide tags into result. Configuration:

[[inputs.snmp.table]]
name = "ciscoPowerEntity"
index_as_tag = true

[[inputs.snmp.table.field]]
name = "PortPwrConsumption"
oid = "CISCO-POWER-ETHERNET-EXT-MIB::cpeExtPsePortPwrConsumption"

[[inputs.snmp.table.field]]
name = "EntPhyIndex"
oid = "CISCO-POWER-ETHERNET-EXT-MIB::cpeExtPsePortEntPhyIndex"
secondary_index_table = true    # enables joining

[[inputs.snmp.table.field]]
name = "EntPhysicalName"
oid = "ENTITY-MIB::entPhysicalName"
secondary_index_use = true      # this tag is indexed from secondary table
is_tag = true

Result:

> ciscoPowerEntity,EntPhysicalName=GigabitEthernet1/2,index=1.2 EntPhyIndex=1002i,PortPwrConsumption=6643i 1621461148000000000
> ciscoPowerEntity,EntPhysicalName=GigabitEthernet1/6,index=1.6 EntPhyIndex=1006i,PortPwrConsumption=10287i 1621461148000000000
> ciscoPowerEntity,EntPhysicalName=GigabitEthernet1/5,index=1.5 EntPhyIndex=1005i,PortPwrConsumption=8358i 1621461148000000000

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

Metrics

The field and tags will depend on the table and fields configured.

• snmp
  • tags:
    • agent_host (deprecated in 1.29: use source instead)

Example Output

snmp,agent_host=127.0.0.1,sysName=example.org uptime=113319.74 1575509815000000000
interface,agent_host=127.0.0.1,ifDescr=wlan0,ifIndex=3,sysName=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,sysName=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,sysName=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