SNMP input plugin - Add table feature

[titilambert]

After a discussion with @TheFlyingCorpse, we designed a new config file like this:

[[plugins.snmp]]
  snmptranslatefile = "/tmp/oids.txt"
  # HOST
  [[plugins.snmp.host]]
    address = "192.168.2.2:161"
    community = "public"
    version = 2
    timeout = 2.0
    collect = ["sysuptime", "ifspeed"]
    [[plugins.snmp.host.table]]
      name = "iftable"
      include_instances = ["eth0", "eth1"]

  [[plugins.snmp.host]]
    address = "192.168.2.3:161"
    community = "public"
    version = 2
    timeout = 2.0
    collect = ["sysuptime"]
    [[plugins.snmp.host.table]]
      name = "iftable"
      exclude_instances = ["eth10", "eth20"]

  # SNMP GET
  [[plugins.snmp.get]]
    name = "sysuptime"
    oid = ".1.3.6.1.2.1.1.3.0"
    unit = "seconds"
    snmptranslate = true

  # SNMP BULK
  [[plugins.snmp.bulk]]
    name = "ifspeed"
    max_repetition = 127
    oid = ".1.3.6.1.2.1.2.2.1.5"

  # SNMP TABLE
  [[inputs.snmp.table]]
    name = "iftable"
    oid = ".1.3.6.1.2.1.31.1.1.1"
    # if empty get all instances
    mapping_table = ".1.3.6.1.2.1.31.1.1.1.1" 
    # if empty get all subtables
    # sub_tables could be not "real subtables"  
    sub_tables=[".1.3.6.1.2.1.2.2.1.13", "bytes_recv", "bytes_send"]
    snmptranslate = true

  # SNMP SUBTABLE
  [[plugins.snmp.subtable]]
    name = "bytes_recv"
    oid = ".1.3.6.1.2.1.31.1.1.1.6"
    unit = "octets"

  [[plugins.snmp.subtable]]
    name = "bytes_send"
    oid = ".1.3.6.1.2.1.31.1.1.1.10"
    unit = "octets"

[cwegener]

👍
I would love to be able to easily get multiple metrics(columns) from tables with many instances/rows (~100).

I don't understand the concept of 'SNMP SUBTABLE' and 'mapping_table' though.
Could you explain those 2 concepts? I can't find them used in any of the net-snmp apps.

[titilambert]

@cwegener Hello ! This is not net-snmp concepts. It's just two small concepts for this plugin to make configuration easier.

[tux-00]

Is it possible to change the polling interval by requests ?

[titilambert]

Yes ! This is a feature of telegraf. You can specify an interval by plugin conf :

[[plugins.snmp]]
  interval = "30s"
  snmptranslatefile = "/tmp/oids.txt"
  # HOST
  [[plugins.snmp.host]]
    address = "192.168.2.2:161"
    community = "public"
    version = 2
    timeout = 2.0
    collect = ["sysuptime"]
  # SNMP GET
  [[plugins.snmp.get]]
    name = "sysuptime"
    oid = ".1.3.6.1.2.1.1.3.0"
    unit = "seconds"


[[plugins.snmp]]
  interval = "5m"
  snmptranslatefile = "/tmp/oids.txt"
  # HOST
  [[plugins.snmp.host]]
    address = "192.168.2.2:161"
    community = "public"
    version = 2
    timeout = 2.0
    collect = ["sysuptime"]
  # SNMP GET
  [[plugins.snmp.get]]
    name = "sysuptime"
    oid = ".1.3.6.1.2.1.1.3.0"
    unit = "seconds"

See example: https://github.com/influxdata/telegraf/blob/master/internal/config/testdata/single_plugin.toml

[tux-00]

Nice!
Maybe can we put an example line in the sample config file ?

Because this is not always evident. (#704)