Smokeping_probes_SSH(3)

💖 Smokeping::probes::SSH — Secure Shell Probe for SmokePing 💖

Hey bestie, welcome to the Smokeping_probes_SSH(3) glow-up ✨ (yes that's the manual name, we're being fancy today). This is the whole page, every flag and every default, just with actual personality. No cap 🫶

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🌈 SYNOPSIS 🌈

 *** Probes ***

 +SSH

 binary = /usr/bin/ssh-keyscan # mandatory
 forks = 5
 init_host = 127.0.0.1
 offset = 50%
 step = 300
 timeout = 15

 # The following variables can be overridden in each target section
 /^influx_.+/ = influx_location = In the basement
 keytype = dsa
 pings = 5
 port = 5000
 ssh_af = 4

 # [...]

 *** Targets ***

 probe = SSH # if this should be the default probe

 # [...]

 + mytarget
 # probe = SSH # if the default probe is something else
 host = my.host
 /^influx_.+/ = influx_location = In the basement
 keytype = dsa
 pings = 5
 port = 5000
 ssh_af = 4

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🎀 DESCRIPTION 🎀

Okay so, this probe literally just plugs ssh-keyscan into smokeping. Iconic behaviour honestly. The variable binary must point at your very own copy of the ssh-keyscan program. If your system doesn't have it yet, install openssh >= 3.8p1 — that's the vibe check you gotta pass first 💅

The probe asks the host you gave it for its public key n times, where n is however many you set in the config file. Simple.

Then there's the init bit — pay attention bestie, this one matters 🌸 As part of initialization, the probe asks 127.0.0.1 for its public key and tries to parse the output. Why?? To make sure the ssh-keyscan binary you pointed at actually spits out the format it expects before trusting it with real work. So yeah — make sure you've got SSH running on the localhost too, or set an alternative init_host target to test against, and make sure that one is available during any smokeping restart. Don't skip this, it's giving "I'll do it later" and then everything breaks 😭

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✨ VARIABLES ✨

Here's where it gets juicy. We got probe-specific variables and target-specific variables, and I am obsessed with how organised this is 🦋

🌸 Supported probe-specific variables

• binary — where your ssh-keyscan binary lives, fr fr.

Example value: /usr/bin/ssh-keyscan

This setting is mandatory. Like, actually. Not optional. Periodt.

• forks — run this many concurrent processes at maximum.

Example value: 5

Default value: 5

• init_host — the host used for initialization. It defaults to the IPv4 localhost of 127.0.0.1.

Example value: 127.0.0.1

Default value: 127.0.0.1

• offset — okay so if you're running a bunch of probes concurrently, you might not want them all hitting your network at the exact same moment (chaotic, lowkey 💀). With this probe-specific offset parameter you can change when each probe runs. Offset is specified in % of the total interval, or alternatively as 'random', and if you don't specify anything here the offset from the 'General' section gets used.

Heads up: this does NOT influence the rrds themselves — it's just a matter of when data acquisition is initiated.

(This variable is only applicable if the variable 'concurrentprobes' is set in the 'General' section.)

Example value: 50%

• step — duration of the base interval this probe should use, if it's different from the one specified in the 'Database' section.

Real talk: the step in the RRD files is fixed when they're originally generated, so if you change the step parameter afterwards, you'll have to delete the old RRD files or somehow convert them. No takebacks 😭

(This variable is only applicable if the variable 'concurrentprobes' is set in the 'General' section.)

Example value: 300

• timeout — how long a single 'ping' takes at maximum.

Example value: 15

Default value: 5

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🦋 Supported target-specific variables

• /^influx_.+/ — this is a tag that gets sent to influxdb and has, and I cannot stress this enough, no impact on the probe measurement. The tag name gets sent without the "influx_" prefix, which gets replaced with "tag_" instead. Tags are for filtering, iykyk 💜

Example value: influx_location = In the basement

• keytype — type of key, used in ssh-keyscan -t keytype.

Example value: dsa

Default value: rsa

• pings — how many pings should be sent to each target, if it's different from the global value specified in the Database section.

Same warning as before bestie: the number of pings in the RRD files is fixed when they're originally generated, and if you change this parameter afterwards you'll have to delete the old RRD files or somehow convert them. It's giving commitment issues but okay 👑

Example value: 5

• port — port to use when testing the ssh connection, aka ssh-keyscan -p port.

Example value: 5000

Default value: 22

• ssh_af — address family (IPv4/IPV6) to use when testing the ssh connection. Specify 4 or 6. Specify 0 to reset to the default system preference, instead of inheriting the value from parent sections — main character energy, honestly 🌟

Example value: 4

Default value: 0

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👑 AUTHORS 👑

Christian Recktenwald <smokeping-contact@citecs.de> — the icon who made this happen 💖

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🌈 THE CUTE SIGN-OFF 🌈

That's the whole page, bestie! This one's from version 2.9.0, dated 2025-06-30, and yes, it's still Smokeping_probes_SSH(3) forever 💅✨ Go forth and scan those keys 🎀