[feature] spe_switch: Add spe_switch power feature

[ActionHOSchT]

This PR adds the feature to set power for a phoenix_fl_switch over telnet.

Devices connected with single-pair-ethernet can now be set to power off/on/cycle.

To verify, this Driver was tested on a FL SWITCH 2303-8SP1 with FW-version 3.27.01 BETA.
Even if it's a BETA, we got the information that the power control won't experience breaking changes.

Checklist

• Documentation for the feature
• Tests for the feature

• The arguments and description in doc/configuration.rst have been updated

• PR has been tested

[Bastian-Krause]

Looks mostly good to me.

CI test errors are not your fault, #1277 fixes them.

FYI: there is also https://github.com/pdudaemon/pdudaemon, a project that focuses only on PDUs. labgrid's PDUDaemonDriver interfaces with it. So it might be worth a thought to implement this rather over there. Let us know how you think about this.

Note: we should wait for #1277 and rebase this to make CI run this before merging.

[Bastian-Krause]

I am not sure about the backend name. The complete name of your device is "Phoenix Contact FL SWITCH 2303-8SP1". Could you find out which products use the same "telnet API"? Maybe have look at the firmware? Maybe something like "phoenixcontact_fl_2300"?

[SeminSey]

Name has been adjusted.

[jluebbe]

Please also squashfs the existing commits into one with a title following our usual conventions, like "driver/power: add backend for Phoenix Contact FL 2303-8SP1 SPE switch".

Adding support for the telnet scheme in labgrid/driver/powerdriver.py should be a separate commit.

Otherwise it looks good.

[jluebbe]

Instead of hardcoding the credentials, you could use a URL like telnet://admin:private@1.2.3.4/ as the host. You'd need to add telnet as a scheme in https://github.com/labgrid-project/labgrid/blob/master/labgrid/driver/powerdriver.py#L194

[ActionHOSchT]

This would indeed be nice.

I used netio_kshell.py as inspiration for the phoenix_fl_switch.py .
Implementing a new scheme would be some effort.

If you want me to put this suggestion on our todo this will be noted ?

[ChHapp]

Is this request mandantory to get this PR upstream ?
The overall goal is to port all labgrid-drivers to PDUDaemon, right ?

[SeminSey]

Commits have been squashed as requested.

[ActionHOSchT]

Since I will be no longer collaborating with JUMO and therefore have no setup to test changes, I close this PR.

[Bastian-Krause]

Reopened as requested by @JUMO-GmbH-Co-KG.

[Emantor]

According to the product page, this device also supports snmp, does it support power switching via SNMP as well? This would be less fragile vs implementing this via pexpect over telnet.

[ChHapp]

Hi @Emantor,

We contacted Phoenix Contact round about seven months ago and asked them how we could remotely control the ports.
They prepared a test firmware (FW version 3.27.01 BETA) for us and we sent them feedback that everything worked just fine with this beta FW. So they told us that this feature would definitely be part of the next release. I understand your concerns about the Telenet API, to be honest I have no idea if it will break soon or not.
To put it in a nutshell, as far as we know, that's the way to go at the moment.