networkmanager: network-online --wants--> NetworkManager-wait-online

[dtzWill]

Motivation for this change

Services relying on network-online.target were running before
the network was ready, every time.

Looking at why this was happening, it seems our network-online
had no actual dependency on the appropriate connectivity check
when using networkmanager, namely NetworkManager-wait-online.service.

(we get this right for configurations using networkd, I believe)

Looking at networkmanager's provided service
etc/systemd/system/NetworkManager-wait-online.service there's
a WantedBy in [Install] that should be accounted for.

Running this command before/after the included commit should
help see the difference:

(this is after:)

$ systemctl show -p Wants,After network-online.target
Wants=NetworkManager-wait-online.service
After=network.target NetworkManager-wait-online.service

Now my services don't all complain when trying to run
just a tiny bit too early in my boot :).

If there's agreement this is the correct configuration
please 'backport' to at least 19.03.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.

---

[etu]

@dtzWill I've just tried this on my 19.03 system that didn't run NetworkManager and had this very same issue. Now it runs network manager with this wait online target added and it works like a charm. So I'm very much in favor of pulling this in, not sure about @NixOS/backports though.

Also, this same issue does exists with the regular networking.dhcpcd.enable, but yeah, that's another issue.

[samueldr]

I feel backporting should be fine, considering this is a bugfix, unless it is expected that adding this dependency could break setups.

I'm not familiar enough with systemd to say for sure if this could cause issues for dependency chains. Though from what I know it feels alright.

[dtzWill]

(requesting review from networkmanager maintainers)

[dtzWill]

Beep boop, is lack of feedback approval or a request for more time?

[dtzWill]

Welp, here we go. Hopefully it fixes more than it breaks overall. LMK if you have questions/problems.

[fpletz]

Thanks! 👍