LLDP Sensor Broken when connecting to Junos devices

[Mierdin]

Just wanted to note that the LLDP sensor is currently broken for Junos devices - hanging on the call to device.open(), just as described in Juniper/py-junos-eznc#579. Totally blocks, so subsequent polls don't happen. Sensor is effectively stopped

I'm running 2.9.1, will try again on 2.10.1

Guessing this is related to the eventlet changes at around the 2.7 timeframe

[Kami]

Just wondering if it's perhaps dns related since eventlet had some issues and regression (which should be fixed in the last version) in the used greendns library.

Or you are directly connecting to the IP and not hostname?

[Mierdin]

I've tried both - and in fact I've even tried cutting NAPALM out and going directly to PyEZ, and hard-coding values in the sensor code directly. I'd bet I would get the same result if I went down to ncclient too, since it appears the source of the problem goes as far down as paramiko.

[Mierdin]

I am on a little bit of a deadline so my current plan is to move forward with 2.6 so I don't have the updated eventlet, and then circle back with this after. Haven't had too much of a chance to dig in super deep yet.

[Mierdin]

Quick update - I'm not entirely sure this is due to the 2.7 changes anymore. I was looking at the ncclient releases, which is a downstream dependency of pyez, which is what NAPALM uses to communicate with Junos devices (and really any NETCONF device) and noticed they moved to selectors instead of select in 0.6.2. I haven't yet drilled into exactly what's causing the problem, but on a hunch, I statically pinned ncclient to v0.6.0, and things are working again.

Obviously pinning to 0.6.0 isn't the most stellar long-term solution, but a good temporary workaround for the time being.

[Kami]

This does sound plausible.

IIRC, we had issues with selectors modules in the past and needed to add some workaround code to make it work - StackStorm/st2@271a54e, StackStorm/st2@922b065.

Do they use selectors backport module for Python 2.x or they only use selectors in Python 3.x where it's available by default?

If they also use it in 2.7, we might need to modify that code to also try to patch it under 2.7 if selectors module is available.

If you feel adventurous and just want to test it out with the latest version of ncclient, I would modify use_select_poll_workaround a bit so it also tries to apply that patch under Python 2.7 and then call it inside your action code (at the very top of the module before ncclientis imported).