[launch] add support for --bridged network

[Saviq]

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For context: the other options we were considering (--public, --exposed) would not be intuitive to anyone. Even if "bridging" isn't strictly correct, e.g. on Hyper-V, that is the term other hypervisors use and people that know what it is will likely know from the get go what it's about. Even ourselves we refer to the feature as "bridging", because that's the prevalent term.

I decided against validating on multipass set local.bridged-interface as the given interface may not exist at that point in time for whatever reason, and on launch we'll communicate well what the problem is, if any.

[codecov]

Codecov Report

Merging #2074 (3e98060) into main (9f18346) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #2074      +/-   ##
==========================================
+ Coverage   81.45%   81.48%   +0.02%     
==========================================
  Files         184      184              
  Lines        9442     9456      +14     
==========================================
+ Hits         7691     7705      +14     
  Misses       1751     1751              

Impacted Files	Coverage Δ
src/client/cli/cmd/launch.cpp	75.78% <100.00%> (+0.33%)	⬆️
src/daemon/daemon.cpp	54.41% <100.00%> (+0.35%)	⬆️
src/utils/settings.cpp	22.09% <100.00%> (+0.91%)	⬆️

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[luis4a0]

Thanks for this @Saviq! The name --bridged sounds the best option to me.

The code looks good, I only have a minor concern with respect to the functionality: what happens if the host has an interface named 'bridged'? I think we should provide a way to bridge it. I know this is unlikely, but it's still possible.

One possibility I see to address this corner case is to allow --network id=bridged. WDYT?

[Saviq]

One possibility I see to address this corner case is to allow --network id=bridged. WDYT?

That would require us to change the RPC and CLI (--bridged and --network bridged would no longer be shortcuts for id=bridged) for tiny gain. IMO not worth it, but let me know if you think otherwise.

[luis4a0]

Well, I don't think this is strictly necessary at that cost. It would be nice to have if easier to implement. Let's leave it like it is now and if some user complains at some point, we can think again about it.

[Saviq]

@LuisP I added the tweak to only restart in the daemon if the driver changed. Unfortunately I was unable to add a reliable test, but didn't want to block on it.

[luis4a0]

Looks good, thanks!

[Saviq]

@luis4a0 I reverted the recent changes, went back to just adding the setting and --bridged option. I'll work on preventing the unnecessary restart in a separate PR.

[luis4a0]

bors r+

[bors]

Build failed:

• macOS

[Saviq]

bors retry

[bors]

Canceled.

[Saviq]

bors r=luis4a0,Saviq

[Saviq]

bors cancel

[bors]

Canceled.

[Saviq]

bors retry

[Saviq]

bors r=luis4a0,Saviq

[bors]

Build failed:

• CI (Linux, lxd)

[Saviq]

bors retry

[bors]

Build failed:

• CI (Linux, lxd)

[Saviq]

One last time.

bors retry

[bors]

Build succeeded:

• CI (Linux, lxd)
• CI (Linux, qemu)
• CI (macOS, hyperkit)
• CI (Windows, hyperv)
• Linux
• macOS
• Windows