Adding discovering and polling support for BGP sessions defined inside VRFs on Arista.

[lprosch]

Reads VRFs from DB and executes snmp walks tailored to Arista to discover BGP sessions defined in VRFs other than "default". Also supports polling data from non-default BGP sessions.

DO NOT DELETE THE UNDERLYING TEXT

Please note

Please read this information carefully. You can run ./lnms dev:check to check your code before submitting.

• [x] Have you followed our code guidelines?
• [x] If my Pull Request does some changes/fixes/enhancements in the WebUI, I have inserted a screenshot of it.
• [x] If my Pull Request makes discovery/polling/yaml changes, I have added/updated test data.

Testers

If you would like to test this pull request then please run: ./scripts/github-apply <pr_id>, i.e ./scripts/github-apply 5926 After you are done testing, you can remove the changes with ./scripts/github-remove. If there are schema changes, you can ask on discord how to revert.

[CLAassistant]

All committers have signed the CLA.

[dhunteratg]

@lprosch Does this support SNMPv3 credentials or just v2? I see some mentions of community in your added code, so I wouldn't be able to test this if it doesn't support v3. Thanks!

[murrant]

using the modern SnmpQuery instead of snmp_walk, this can support snmpv2 and v3 easily with the ->context() modifier.

[PipoCanaja]

force test re-run

[murrant]

If someone can generate some test data for this, I can convert it to SnmpQuery as required.

[github-actions[bot]]

Please add test data so we can ensure your change is not broken in the future. Read the docs to find out how: https://docs.librenms.org/Developing/os/Test-Units

[lprosch]

We produced this testdata. Is this correct? testdata.zip

[lprosch]

@murrant I hope, its ok to ping you this way. We provided some testdata. Is this helpful this way?