bug#63516: Static networking should wait for interfaces to be up

["Ludovic Courtès" <ludovic.courtes@inria.fr>]

Hi!

With shepherd 0.10.0 starting services in parallel, I observed
‘networking’ (from ‘static-networking-service-type’) starting too early,
before the corresponding interfaces were available:

--8<---------------cut here---------------start------------->8---
[   21.863249] shepherd[1]: Service udev started.
[   21.863414] shepherd[1]: Service udev running with value 196.
[   21.865686] shepherd[1]: Starting service networking...
[   21.865822] shepherd[1]: Starting service file-system-/boot/efi...
[   21.986025] shepherd[1]: Exception caught while starting #<<service> 7f9bf08434e0>: (no-such-device "eno1"
[   22.738237] udevd[196]: starting eudev-3.2.11
[   22.767830] udevd[196]: no sender credentials received, message ignored

[...]

[   23.562275] tg3 0000:05:00.0 eth0: Tigon3 [partno(BCM95720) rev 5720000] (PCI Express) MAC address b8:cb:2
[   23.562290] tg3 0000:05:00.0 eth0: attached PHY is 5720C (10/100/1000Base-T Ethernet) (WireSpeed[1], EEE[1
[   23.562298] tg3 0000:05:00.0 eth0: RXcsums[1] LinkChgREG[0] MIirq[0] ASF[1] TSOcap[1]
[   23.562305] tg3 0000:05:00.0 eth0: dma_rwctrl[00000001] dma_mask[64-bit]
[   23.596221] tg3 0000:05:00.1 eth1: Tigon3 [partno(BCM95720) rev 5720000] (PCI Express) MAC address b8:cb:2
[   23.596234] tg3 0000:05:00.1 eth1: attached PHY is 5720C (10/100/1000Base-T Ethernet) (WireSpeed[1], EEE[1
[   23.596242] tg3 0000:05:00.1 eth1: RXcsums[1] LinkChgREG[0] MIirq[0] ASF[1] TSOcap[1]
[   23.596249] tg3 0000:05:00.1 eth1: dma_rwctrl[00000001] dma_mask[64-bit]
[   23.599725] tg3 0000:05:00.0 eno1: renamed from eth0
[   23.613468] iTCO_vendor_support: vendor-support=0
[   23.619114] iTCO_wdt iTCO_wdt: Found a Intel PCH TCO device (Version=6, TCOBASE=0x0400)
[   23.619327] iTCO_wdt iTCO_wdt: initialized. heartbeat=30 sec (nowayout=0)
[   23.645196] tg3 0000:05:00.1 eno2: renamed from eth1
[   23.727153] Error: Driver 'pcspkr' is already registered, aborting...
[   23.738237] ipmi_si dmi-ipmi-si.0: Removing SMBIOS-specified kcs state machine in favor of ACPI
[   23.738239] ipmi_si: Adding ACPI-specified kcs state machine
[   23.738273] ipmi_si: Trying ACPI-specified kcs state machine at i/o address 0xca8, slave address 0x20, irq
[   23.926348] shepherd[1]: Service file-system-/boot/efi has been started.
[   23.927164] shepherd[1]: Service networking failed to start.
--8<---------------cut here---------------end--------------->8---

Before doing ‘addr-add’ in ‘network-set-up/linux’, should we wait for
the interface to show up, by calling ‘get-links’ from Guile-Netlink or
something like that?

Ludo’.