Improve power supply information in get_enviornment()

[ckishimo]

This PR will improve the output of get_environment(), as the command show chassis power available in some platforms reports capacity and output per power supply

<rpc-reply xmlns:junos="http://xml.juniper.net/junos/17.3R1/junos">
    <rpc>
        <get-power-usage-information>
        </get-power-usage-information>
    </rpc>
    <cli>
        <banner></banner>
    </cli>
</rpc-reply>

Example:

user@juniper> show chassis power                      

PEM 0:
  State:     Online
  Capacity:  2700 W (maximum 2700 W)
  DC output: 612 W (zone 0, 51 A at 12 V, 22% of capacity)

PEM 1:
  State:     Online
  Capacity:  2700 W (maximum 2700 W)
  DC output: 612 W (zone 0, 51 A at 12 V, 22% of capacity)

PEM 2:
  State:     Online
  Capacity:  2700 W (maximum 2700 W)
  DC output: 612 W (zone 0, 51 A at 12 V, 22% of capacity)

PEM 3:
  State:     Online
  Capacity:  2700 W (maximum 2700 W)
  DC output: 624 W (zone 0, 52 A at 12 V, 23% of capacity)

The output from get_environment() will be now:

    "power": {
        "Power Supply 0": {
            "capacity": 2700, 
            "output": 612, 
            "status": true
        }, 
        "Power Supply 1": {
            "capacity": 2700, 
            "output": 612, 
            "status": true
        }, 
        "Power Supply 2": {
            "capacity": 2700, 
            "output": 612, 
            "status": true
        }, 
        "Power Supply 3": {
            "capacity": 2700, 
            "output": 624, 
            "status": true
        }, 
        .....

Let me know. Thanks

[mirceaulinic]

What platforms have support for this?

[ckishimo]

I don't know... I only know it works for a QFX10k but it does not work in the qfx5110-48s-4c. I do not have access to other platforms to test that...

user@juniper> show chassis power 
error: command is not valid on the qfx5110-48s-4c

According to https://www.juniper.net/documentation/en_US/junos/topics/reference/command-summary/show-chassis-power.html this command is supported in the MX (same output), also
supported in the PTX (but the output is different) and EX9200

[mirceaulinic]

Alright, that tends to be very obscure... I check on MX and it is fine.

[mirceaulinic]

Okay, this seems to break the test case for the virtual chassis, as virtual chassis most probably don't have the power supply section. Can you please check @ckishimo?

[coveralls]

Coverage decreased (-0.08%) to 78.766% when pulling 35bb0e5 on ckishimo:devel-psu into 21c3512 on napalm-automation:develop.

[mirceaulinic]

@ckishimo if you add this file here, it means a device that does not have this capability, for example your qfx5110-48s-4c, does not error when retrieving this RPC & returns exactly this XML back. Is this correct?

[ckishimo]

@mirceaulinic not sure I'm following... the qfx5110 does not have this capability but it does not error as the get() is within the try...except clause. The two files I committed are just to pass the failing tests... The qfx5110 will indeed fail when retrieving the RPC:
jnpr.junos.exception.RpcError: RpcError(severity: error, bad_element: None, message: command is not valid on the qfx5110-48s-4c)
I don't have other devices (ie: virtual chassis) to test this more extensively... 😢

[mirceaulinic]

Yeah, agreed there's no good way to reproduce a RpcError using mock files.