Awesome
Sunt
SNMP Agent for Linux written in Rust.
Intro
SNMP is still the common ground for getting data into various kinds of monitoring systems. Sunt aims to be a modern SNMP agent that is aware of how things are run nowadays, stripped to the essentials but adding features where they make sense.
Supported tables:
- hrStorageTable
- dskTable
- diskIOTable
- ifTable
- nsExtendOutput1Table (SNMP extend)
Example queries
snmpwalk -v2c -c test 127.0.0.1 .1
snmptable -v2c -c sunt 127.0.0.1 hrStorageTable
snmptable -v2c -c sunt 127.0.0.1 dskTable
snmptable -v2c -c sunt 127.0.0.1 diskIOTable
snmptable -v2c -c sunt 127.0.0.1 ifTable
snmpbulkwalk -v2c -c test 127.0.0.1 dskTable
snmpbulkwalk -v2c -c derp 127.0.0.1 .1.3.6.1.2.1.31.1.1.1
.
# snmptable -v2c -c sunt 192.168.0.1 dskTable | cut -c -140
SNMP table: UCD-SNMP-MIB::dskTable
dskIndex dskPath dskDevice dskMinimum dskMinPercent dskTotal dskAvail dskUsed dskPercent dskPercentNode
1 / /dev/vghive/root 0 -1 20511356 11301592 8144804 39 16
2 /data /dev/md0 0 -1 961300936 333643156 627657780 65 0
3 /var/lib/lxc /dev/vghive/var-lxc 0 -1 20961280 16288304 4672976 22 0
4 /var/log /dev/vghive/var-log 0 -1 10483712 9686808 719080 6 0
5 /media/prometheus /dev/vghive/prometheus 0 -1 10475520 3404028 7071492 67 0
6 /var/lib/libvirt/images /dev/vghive/var-libvirt 0 -1 26204160 6710120 19494040 74 0
7 /media/bkp /dev/bkp 0 -1 15348720 13136192 1409816 9 4
Notable differences to net-snmpd
-
No write access whatsoever
-
No access control, community string is completely ignored
-
hrStorageTable:
- Only actual mountpoints are included (no RAM etc).
- Duplicate mountpoints (bind mounts) are filtered out (useful for Docker/LXC hosts).
-
diskIOTable:
dm-*devices are reported as the actual device, e.g.vghive/dataorcrypted_home.
-
ifTable
- Only Physical interfaces, Bridges and VLAN interfaces are exported (VM interfaces and VPN tunnels are filtered).
-
Considerably faster response
Tested using
time snmptable -v2c -c community host diskIOTable time snmptable -v2c -c community host hrStorageTable time snmptable -v2c -c community host ifTable time snmpbulkwalk -v2c -c community host .1 > /dev/nullOver a local gigabit connection:
Table | Sunt | net-snmpd ---------------- | ---------------------- | -------------------- diskIOTable | real 0m0,028s | real 0m0,038s (26 entries) | user 0m0,019s | user 0m0,020s | sys 0m0,005s | sys 0m0,006s | | hrStorageTable | real 0m0,028s | real 0m0,031s (17 entries) | user 0m0,020s | user 0m0,017s | sys 0m0,006s | sys 0m0,008s | | ifTable | real 0m0,041s | real 0m0,088s (26 entries) | user 0m0,019s | user 0m0,027s | sys 0m0,012s | sys 0m0,011s | | full bulkwalk | real 0m0,041s | real 0m3,183s (start at .1) | user 0m0,021s | user 0m0,360s | sys 0m0,008s | sys 0m0,105s | |Over a remote connection with about 20ms latency:
Table | Sunt | net-snmpd ---------------- | ---------------------- | -------------------- diskIOTable | real 0m0,103s | real 0m0,624s (26 entries) | user 0m0,026s | user 0m0,020s | sys 0m0,012s | sys 0m0,011s | | hrStorageTable | real 0m0,057s | real 0m0,317s (17 entries) | user 0m0,025s | user 0m0,027s | sys 0m0,008s | sys 0m0,012s | | ifTable | real 0m0,130s | real 0m3,474s (26 entries) | user 0m0,022s | user 0m0,044s | sys 0m0,019s | sys 0m0,030s | | full bulkwalk | real 0m0,265s | real 0m55,677s (start at .1) | user 0m0,021s | user 0m0,620s | sys 0m0,007s | sys 0m0,253sNote that this test is somewhat unfair because sunt returns way fewer data.
SNMP Extend support
Sunt has support for SNMP extend. To use it, create a YAML file with a set of commands like this:
extend:
# SNMP extend command for NTP monitoring
ntpq_delay: { cmd: '/usr/local/bin/ntpwatch', args: ['delay' ] }
ntpq_jitter: { cmd: '/usr/local/bin/ntpwatch', args: ['jitter'] }
ntpq_offset: { cmd: '/usr/local/bin/ntpwatch', args: ['offset'] }
"true": { cmd: '/bin/true' }
echo: { cmd: '/bin/echo', args: ["testing"] }
Then start sunt with the -e option, pointing to that yaml file. You can then query the table:
# snmptable -v2c -c wayne 127.0.0.1 nsExtendOutput1Table
SNMP table: NET-SNMP-EXTEND-MIB::nsExtendOutput1Table
nsExtendOutput1Line nsExtendOutputFull nsExtendOutNumLines nsExtendResult
testing testing 1 0
0 0
21217 21217 1 0
650 650 1 0
1580 1580 1 0
Or walk the values:
# snmpwalk -v2c -c wayne 127.0.0.1 nsExtendOutput1Table
NET-SNMP-EXTEND-MIB::nsExtendOutput1Line."echo" = STRING: testing
NET-SNMP-EXTEND-MIB::nsExtendOutput1Line."true" = STRING:
NET-SNMP-EXTEND-MIB::nsExtendOutput1Line."ntpq_delay" = STRING: 21217
NET-SNMP-EXTEND-MIB::nsExtendOutput1Line."ntpq_jitter" = STRING: 650
NET-SNMP-EXTEND-MIB::nsExtendOutput1Line."ntpq_offset" = STRING: 1580
NET-SNMP-EXTEND-MIB::nsExtendOutputFull."echo" = STRING: testing
NET-SNMP-EXTEND-MIB::nsExtendOutputFull."true" = STRING:
NET-SNMP-EXTEND-MIB::nsExtendOutputFull."ntpq_delay" = STRING: 21217
NET-SNMP-EXTEND-MIB::nsExtendOutputFull."ntpq_jitter" = STRING: 650
NET-SNMP-EXTEND-MIB::nsExtendOutputFull."ntpq_offset" = STRING: 1580
NET-SNMP-EXTEND-MIB::nsExtendOutNumLines."echo" = INTEGER: 1
NET-SNMP-EXTEND-MIB::nsExtendOutNumLines."true" = INTEGER: 0
NET-SNMP-EXTEND-MIB::nsExtendOutNumLines."ntpq_delay" = INTEGER: 1
NET-SNMP-EXTEND-MIB::nsExtendOutNumLines."ntpq_jitter" = INTEGER: 1
NET-SNMP-EXTEND-MIB::nsExtendOutNumLines."ntpq_offset" = INTEGER: 1
NET-SNMP-EXTEND-MIB::nsExtendResult."echo" = INTEGER: 0
NET-SNMP-EXTEND-MIB::nsExtendResult."true" = INTEGER: 0
NET-SNMP-EXTEND-MIB::nsExtendResult."ntpq_delay" = INTEGER: 0
NET-SNMP-EXTEND-MIB::nsExtendResult."ntpq_jitter" = INTEGER: 0
NET-SNMP-EXTEND-MIB::nsExtendResult."ntpq_offset" = INTEGER: 0
SNMPv2-SMI::zeroDotZero = No more variables left in this MIB View (It is past the end of the MIB tree)