add flag parsing

[thirdeyenick]

Forgot to parse the domain flag we added recently...

[coveralls]

Pull Request Test Coverage Report for Build 13988284675

Details

• 0 of 1 (0.0%) changed or added relevant line in 1 file are covered.
• 149 unchanged lines in 21 files lost coverage.
• Overall coverage decreased (-0.08%) to 51.331%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
cmd/k8s-nameserver/main.go	0	1	0.0%

Files with Coverage Reduction	New Missed Lines	%
wgengine/userspace.go	1	67.15%
control/controlclient/status.go	2	51.28%
derp/derp_server.go	2	72.58%
k8s-operator/sessionrecording/fakes/fakes.go	2	75.61%
portlist/poller.go	2	83.78%
safesocket/safesocket.go	2	72.34%
types/lazy/deferred.go	2	94.12%
util/syspolicy/rsop/resultant_policy.go	2	94.35%
portlist/portlist.go	3	87.8%
tsnet/tsnet.go	4	71.96%

Totals
Change from base Build 13971239083:	-0.08%
Covered Lines:	55938
Relevant Lines:	108975

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💛 - Coveralls