fetch DHCP leases from networkd

[bhoopesh369]

See xPU sZTP provisioning block

today we pass lease file via cmdline arguments like this: --dhcp-lease-file /var/lib/dhclient/dhclient.leases.

for detecting this automatically using Network manger : #418
but if detection through Network Manager doesn't work, we can then look through networkd same as the above

can we detect that info automatically from networkd over dbus?

[bhoopesh369]

It seems we can't get the lease info via dbus for systemd-networkd. Dbus does not expose the info.
So the only way to to parse all the lease files present in the /run/systemd/netif/leases folder.

WDYT? @glimchb

[bhoopesh369]

The maximum info we can get via dbus is:

array [
      dict entry(
         string "OperationalState"
         variant             string "routable"
      )
      dict entry(
         string "CarrierState"
         variant             string "carrier"
      )
      dict entry(
         string "AddressState"
         variant             string "routable"
      )
      dict entry(
         string "IPv4AddressState"
         variant             string "routable"
      )
      dict entry(
         string "IPv6AddressState"
         variant             string "degraded"
      )
      dict entry(
         string "OnlineState"
         variant             string "online"
      )
      dict entry(
         string "AdministrativeState"
         variant             string "configured"
      )
      dict entry(
         string "BitRates"
         variant             struct {
               uint64 18446744073709551615
               uint64 18446744073709551615
            }
      )
   ]

[glimchb]

It seems we can't get the lease info via dbus for systemd-networkd. Dbus does not expose the info. So the only way to to parse all the lease files present in the /run/systemd/netif/leases folder.

WDYT? @glimchb

copy paste please an example of this folder