We have several places where we call applySysPolicy, suggestExitNodeLocked, and setExitNodeID.
While there are cases where we want to resolve the exit node specifically, such as when network
conditions change or a new netmap is received, we typically need to perform all three steps.
For example, enforcing policy settings may enable auto exit nodes or set an ExitNodeIP,
which in turn requires picking a suggested exit node or resolving the IP to an ID, respectively.
In this PR, we introduce (*LocalBackend).resolveExitNodeInPrefsLocked and (*LocalBackend).reconcilePrefsLocked,
with the latter calling both applySysPolicy and resolveExitNodeInPrefsLocked.
Consolidating these steps into a single extensibility point would also make it easier to support
future hooks registered by ipnext extensions.
Updates tailscale/corp#29969
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Nick Khyl
cb7b49941e