Checking for network online

[Johnathan Mantey]

/I/ntel has recently run into an issue regarding a systemd service, and 
we're interested in soliciting feedback from the community.

Issue: systemd-networkd-wait-online.service stalls for 120 seconds when 
the managed NICs do not have a network connection.

TLDR: Should OpenBMC remove systemd-networkd-wait-online.service 
universally?

System Config: All NICs in the system are not connected to an active 
network.

Test Process: The system under test (SUT) has AC removed, and some time 
later AC applied. Wait for BMC/BIOS to boot

Behavior: U-Boot hands control to the Linux boot process, and the 
systemd services are started. When systemd-networkd-wait-online.service 
starts it stalls waiting for the NICs to enter a fully functional state. 
This never happens during the default 120 second timeout period for this 
service. When the timeout elapses, an error message is logged to the 
journal reporting the service exited unsuccessfully.

Issues: This service blocks entry to multi-user.target.
phosphor-state-manager uses multi-user.target to report the BMC is ready 
to use.
This is reported via IPMI Get Device ID.
The Intel BIOS is blocked from booting until 
systemd-networkd-wait-online times out.
BMC entry to multi-user.target is delayed. Journal entries are created.

Question for the community: Given the negative side effects caused by 
running this service does the community want to have this service 
collectively removed from global build image?

-- 
Johnathan Mantey
Senior Software Engineer
*azad te**chnology partners*
Contributing to Technology Innovation since 1992
Phone: (503) 712-6764
Email: johnathanx.mantey at intel.com

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