Saves 328 KB (2.5%) off the minimal binary.
For IoT devices that don't need MagicDNS (e.g. they don't make
outbound connections), this provides a knob to disable all the DNS
functionality.
Rather than a massive refactor today, this uses constant false values
as a deadcode sledgehammer, guided by shotizam to find the largest DNS
functions which survived deadcode.
A future refactor could make it so that the net/dns/resolver and
publicdns packages don't even show up in the import graph (along with
their imports) but really it's already pretty good looking with just
these consts, so it's not at the top of my list to refactor it more
soon.
Also do the same in a few places with the ACME (cert) functionality,
as I saw those while searching for DNS stuff.
Updates #12614
Change-Id: I8e459f595c2fde68ca16503ff61c8ab339871f97
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We update profileManager to allow registering a single state (profile+prefs) change hook.
This is to invert the dependency between the profileManager and the LocalBackend, so that
instead of LocalBackend asking profileManager for the state, we can have profileManager
call LocalBackend when the state changes.
We also update feature.Hook with a new (*feature.Hook).GetOk method to avoid calling both
IsSet and Get.
Updates tailscale/corp#28014
Updates #12614
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Now that 25c4dc5fd7 removed unregistering hooks and made them into
slices, just expose the slices and remove the setter funcs.
This removes boilerplate ceremony around adding new hooks.
This does export the hooks and make them mutable at runtime in theory,
but that'd be a data race. If we really wanted to lock it down in the
future we could make the feature.Hooks slice type be an opaque struct
with an All() iterator and a "frozen" bool and we could freeze all the
hooks after init. But that doesn't seem worth it.
This means that hook registration is also now all in one place, rather
than being mixed into ProfilesService vs ipnext.Host vs FooService vs
BarService. I view that as a feature. When we have a ton of hooks and
the list is long, then we can rearrange the fields in the Hooks struct
as needed, or make sub-structs, or big comments.
Updates #12614
Change-Id: I05ce5baa45a61e79c04591c2043c05f3288d8587
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Still behind the same ts_omit_tap build tag.
See #14738 for background on the pattern.
Updates #12614
Change-Id: I03fb3d2bf137111e727415bd8e713d8568156ecc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This pulls out the Wake-on-LAN (WoL) code out into its own package
(feature/wakeonlan) that registers itself with various new hooks
around tailscaled.
Then a new build tag (ts_omit_wakeonlan) causes the package to not
even be linked in the binary.
Ohter new packages include:
* feature: to just record which features are loaded. Future:
dependencies between features.
* feature/condregister: the package with all the build tags
that tailscaled, tsnet, and the Tailscale Xcode project
extension can empty (underscore) import to load features
as a function of the defined build tags.
Future commits will move of our "ts_omit_foo" build tags into this
style.
Updates #12614
Change-Id: I9c5378dafb1113b62b816aabef02714db3fc9c4a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Brad Fitzpatrick
Nick Khyl