dom/telegraf
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Rewrite documentation for snmp input (#6802)

Browse Source
This commit is contained in:
Daniel Nelson
2019-12-30 11:33:32 -08:00
committed by GitHub
parent f035d44fe1
commit c325c94a96
6 changed files with 278 additions and 381 deletions
Download Patch File Download Diff File Expand all files Collapse all files

319
plugins/inputs/snmp/README.md
View File

@@ -1,180 +1,221 @@
# SNMP Plugin
# SNMP Input Plugin
The SNMP input plugin gathers metrics from SNMP agents.
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.
## Configuration:
### Prerequisites
See additional SNMP plugin configuration examples [here](./CONFIG-EXAMPLES.md).
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.
### Example:
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`][man snmpcmd] for more
information.
SNMP data:
```
.1.0.0.0.1.1.0 octet_str "foo"
.1.0.0.0.1.1.1 octet_str "bar"
.1.0.0.0.1.102 octet_str "bad"
.1.0.0.0.1.2.0 integer 1
.1.0.0.0.1.2.1 integer 2
.1.0.0.0.1.3.0 octet_str "0.123"
.1.0.0.0.1.3.1 octet_str "0.456"
.1.0.0.0.1.3.2 octet_str "9.999"
.1.0.0.1.1 octet_str "baz"
.1.0.0.1.2 uinteger 54321
.1.0.0.1.3 uinteger 234
```
Telegraf config:
### Configuration
```toml
[[inputs.snmp]]
agents = [ "127.0.0.1:161" ]
version = 2
community = "public"
## Agent addresses to retrieve values from.
## example: agents = ["udp://127.0.0.1:161"]
## agents = ["tcp://127.0.0.1:161"]
agents = ["udp://127.0.0.1:161"]
name = "system"
[[inputs.snmp.field]]
name = "hostname"
oid = ".1.0.0.1.1"
is_tag = true
## Timeout for each request.
# timeout = "5s"
## SNMP version; can be 1, 2, or 3.
# version = 2
## SNMP community string.
# community = "public"
## 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", 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" or "".
# 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"
oid = ".1.0.0.1.2"
[[inputs.snmp.field]]
name = "loadavg"
oid = ".1.0.0.1.3"
conversion = "float(2)"
[[inputs.snmp.table]]
name = "remote_servers"
inherit_tags = [ "hostname" ]
[[inputs.snmp.table.field]]
name = "server"
oid = ".1.0.0.0.1.1"
is_tag = true
[[inputs.snmp.table.field]]
name = "connections"
oid = ".1.0.0.0.1.2"
[[inputs.snmp.table.field]]
name = "latency"
oid = ".1.0.0.0.1.3"
conversion = "float"
```
Resulting output:
```
* Plugin: snmp, Collection 1
> system,agent_host=127.0.0.1,host=mylocalhost,hostname=baz loadavg=2.34,uptime=54321i 1468953135000000000
> remote_servers,agent_host=127.0.0.1,host=mylocalhost,hostname=baz,server=foo connections=1i,latency=0.123 1468953135000000000
> remote_servers,agent_host=127.0.0.1,host=mylocalhost,hostname=baz,server=bar connections=2i,latency=0.456 1468953135000000000
```
#### Configuration via MIB:
This example uses the SNMP data above, but is configured via the MIB.
The example MIB file can be found in the `testdata` directory. See the [MIB lookups](#mib-lookups) section for more information.
Telegraf config:
```toml
[[inputs.snmp]]
agents = [ "127.0.0.1:161" ]
version = 2
community = "public"
[[inputs.snmp.field]]
oid = "TEST::hostname"
oid = "RFC1213-MIB::sysName.0"
name = "source"
is_tag = true
[[inputs.snmp.table]]
oid = "TEST::testTable"
inherit_tags = [ "hostname" ]
oid = "IF-MIB::ifTable"
name = "interface"
inherit_tags = ["source"]
[[inputs.snmp.table.field]]
oid = "IF-MIB::ifDescr"
name = "ifDescr"
is_tag = true
```
Resulting output:
```
* Plugin: snmp, Collection 1
> testTable,agent_host=127.0.0.1,host=mylocalhost,hostname=baz,server=foo connections=1i,latency="0.123" 1468953135000000000
> testTable,agent_host=127.0.0.1,host=mylocalhost,hostname=baz,server=bar connections=2i,latency="0.456" 1468953135000000000
#### 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.
```toml
[[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. Efficively 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.
# conversion = ""
```
### Config parameters
##### Table
* `agents`: Default: `[]`
List of SNMP agents to connect to in the form of `[tcp://]IP[:PORT]`. If `:PORT` is unspecified, it defaults to `161`. When using the optional prefix `tcp://`, SNMP over TCP will be used. Otherwise UDP is used as the transport protocol.
Use a `table` to configure the collection of a SNMP table. SNMP requests
formed with this option operate similarly way to the `snmptable` command.
* `version`: Default: `2`
SNMP protocol version to use.
Control the handling of specific table columns using a nested `field`. These
nested fields are specified similarly to a top-level `field`.
* `community`: Default: `"public"`
SNMP community to use.
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 exclude
columns use [metric filtering][].
* `max_repetitions`: Default: `50`
Maximum number of iterations for repeating variables.
One [metric][] is created for each row of the SNMP table.
* `sec_name`:
Security name for authenticated SNMPv3 requests.
```toml
[[inputs.snmp]]
# ... snip ...
* `auth_protocol`: Values: `"MD5"`,`"SHA"`,`""`. Default: `""`
Authentication protocol for authenticated SNMPv3 requests.
[[inputs.snmp.table]]
## Object identifier of the SNMP table as a numeric or textual OID.
oid = "IF-MIB::ifTable"
* `auth_password`:
Authentication password for authenticated SNMPv3 requests.
## 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 = ""
* `sec_level`: Values: `"noAuthNoPriv"`,`"authNoPriv"`,`"authPriv"`. Default: `"noAuthNoPriv"`
Security level used for SNMPv3 messages.
## 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 = []
* `context_name`:
Context name used for SNMPv3 requests.
## 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
* `priv_protocol`: Values: `"DES"`,`"AES"`,`""`. Default: `""`
Privacy protocol used for encrypted SNMPv3 messages.
[[inputs.snmp.table.field]]
## OID to get. May be a numeric or textual module-qualified OID.
oid = "IF-MIB::ifDescr"
* `priv_password`:
Privacy password used for encrypted SNMPv3 messages.
## 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
* `name`:
Output measurement name.
## The OID sub-identifier to strip off so that the index can be matched
## against other fields in the table.
# oid_index_suffix = ""
#### Field parameters:
* `oid`:
OID to get. May be a numeric or textual OID.
## 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
```
* `oid_index_suffix`:
The OID sub-identifier to strip off so that the index can be matched against other fields in the table.
### Troubleshooting
* `oid_index_length`:
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.
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
```
* `name`:
Output field/tag name.
If not specified, it defaults to the value of `oid`. If `oid` is numeric, an attempt to translate the numeric OID into a texual OID will be made.
Request a top-level field:
```
$ snmpget -v2c -c public 127.0.0.1 sysUpTime.0
```
* `is_tag`:
Output this field as a tag.
Request a table:
```
$ snmptable -v2c -c public 127.0.0.1 ifTable
```
* `conversion`: Values: `"float(X)"`,`"float"`,`"int"`,`""`. Default: `""`
Converts the value according to the given specification.
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
```
- `float(X)`: Converts the input value into a float and divides by the Xth power of 10. Efficively just moves the decimal left X places. For example a value of `123` with `float(2)` will result in `1.23`.
- `float`: Converts the value into a float with no adjustment. Same as `float(0)`.
- `int`: Convertes the value into an integer.
- `hwaddr`: Converts the value to a MAC address.
- `ipaddr`: Converts the value to an IP address.
### Example Output
#### Table parameters:
* `oid`:
Automatically populates the table's fields using data from the MIB.
```
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
```
* `name`:
Output measurement name.
If not specified, it defaults to the value of `oid`. If `oid` is numeric, an attempt to translate the numeric OID into a texual OID will be made.
* `inherit_tags`:
Which tags to inherit from the top-level config and to use in the output of this table's measurement.
* `index_as_tag`:
Adds each row's index within the table as a tag.
### MIB lookups
If the plugin is configured such that it needs to perform lookups from the MIB, it will use the net-snmp utilities `snmptranslate` and `snmptable`.
When performing the lookups, the plugin will load all available MIBs. If your MIB files are in a custom path, you may add the path using the `MIBDIRS` environment variable. See [`man 1 snmpcmd`](http://net-snmp.sourceforge.net/docs/man/snmpcmd.html#lbAK) for more information on the variable.
[net-snmp]: http://www.net-snmp.org/
[man snmpcmd]: http://net-snmp.sourceforge.net/docs/man/snmpcmd.html#lbAK
[metric filtering]: /docs/CONFIGURATION.md#metric-filtering
[metric]: /docs/METRICS.md