invalid memory address or nil pointer dereference Error

[vivekbny]

Hi,

I am getting invalid memory address error when using snmp v3 authentication.
The exporter was working fine with snmpv2 devices with default_if_index module.
Below is the error, yml config , snmpbulwalk command output from the box.

[SuperQ]

Can you run the exporter with -log.level=deubg and attach a text copy (not a screenshot) of the output?

[RichiH]

@SuperQ was minimally faster, so my only remaining point: Please change your login credentials and take care to blank/remove everything, ideally making even the length of the strings invisible to anyone you send this to.

[vivekbny]

@SuperQ and @RichiH thanks for your reply.
Here is the text with the output.
snmpexporter output.txt

[SuperQ]

I traced the error, it looks like it's coming from the upstream SNMP code. I will have to see if there are any related upstream issues filed/fixed.

[vivekbny]

Thanks @SuperQ for your time.
Will wait for the resolution.
Hope i can get the snmp metrics scraped soon.

[SuperQ]

There's nothing specific upstream that I can find after a quick glance through the changes. However it looks like the v3 auth has been refactored since we released the last snmp_exporter. I propose we update the vendoring and test again.

[vivekbny]

okay

[SuperQ]

If possible, can you build a version of the snmp_exporter from master?

[vivekbny]

Never done them before.
i will give a try to build from master.

[SuperQ]

If you have a Golang compiler/build env setup, it should be as easy as go get github.com/prometheus/snmp_exporter and the binary will end up in the bin dir of your build env.

[vivekbny]

No i have not setup Golang
I am off on wed will be back on Thursday to check this.
Meanwhile, is the docker version of the image from dockerhub uses a different buid?
https://hub.docker.com/r/prom/snmp-exporter/
If this image is a latest build can i try with this.
Thanks for your help @SuperQ

[SuperQ]

Here is a snmp_exporter test binary built for Linux x86-64.

snmp_exporter.gz

[vivekbny]

Thanks @SuperQ
Iam now able to scrape the metrics using snmpv3 auth using the new binary you have provided.

Thanks again :)

[SuperQ]

Great! We'll have to make a new official release that contains the updated vendor code.

[SuperQ]

FYI, I've made an official release of the new version.

[tricycleHack]

Hi,

the problem seems to be back:

Using version 0.12.0 with docker image.
SNMPv3 with authPriv mode

Configured everything in configs accordingly:
version: 3
max_repetitions: 25
retries: 3
timeout: 20s
auth: 
security_level: authPriv
username: user
password: safePassword
auth_protocol: SHA
priv_protocol: AES
priv_password: privatePassword

snmpwalk is working with the device, so the problem is not on the side of the device for sure. From log.level=debug returns:

snmp-exporter_1         | time="2018-10-24T13:30:17Z" level=debug msg="Scraping target '192.168.1.1:161' with module 'if_mib'" source="main.go:86"
snmp-exporter_1         | time="2018-10-24T13:30:17Z" level=debug msg="Walking target \"192.168.1.1:161\" subtree \"1.3.6.1.2.1.1.3\"" source="collector.go:125"
snmp-exporter_1         | time="2018-10-24T13:30:17Z" level=info msg="Error scraping target 192.168.1.1:161: Error walking target 192.168.178.6: recover: runtime error: invalid memory address or nil pointer dereference" source="collector.go:180"
snmp-exporter_1         | time="2018-10-24T13:30:17Z" level=debug msg="Scrape of target '192.168.1.1:161' with module 'if_mib' took 60.002449 seconds" source="main.go:97"