all: add ts_omit_tailnetlock as a start of making it build-time modular

Updates #17115

Change-Id: I6b083c0db4c4d359e49eb129d626b7f128f0a9d2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

ipn/ipnlocal/local.go

@@ -82,7 +82,6 @@ import (
 	"tailscale.com/posture"
 	"tailscale.com/syncs"
 	"tailscale.com/tailcfg"
-	"tailscale.com/tka"
 	"tailscale.com/tsd"
 	"tailscale.com/tstime"
 	"tailscale.com/types/appctype"
@@ -7179,53 +7178,6 @@ func (b *LocalBackend) SwitchProfile(profile ipn.ProfileID) error {
 	return b.resetForProfileChangeLockedOnEntry(unlock)
 }
 
-func (b *LocalBackend) initTKALocked() error {
-	cp := b.pm.CurrentProfile()
-	if cp.ID() == "" {
-		b.tka = nil
-		return nil
-	}
-	if b.tka != nil {
-		if b.tka.profile == cp.ID() {
-			// Already initialized.
-			return nil
-		}
-		// As we're switching profiles, we need to reset the TKA to nil.
-		b.tka = nil
-	}
-	root := b.TailscaleVarRoot()
-	if root == "" {
-		b.tka = nil
-		b.logf("network-lock unavailable; no state directory")
-		return nil
-	}
-
-	chonkDir := b.chonkPathLocked()
-	if _, err := os.Stat(chonkDir); err == nil {
-		// The directory exists, which means network-lock has been initialized.
-		storage, err := tka.ChonkDir(chonkDir)
-		if err != nil {
-			return fmt.Errorf("opening tailchonk: %v", err)
-		}
-		authority, err := tka.Open(storage)
-		if err != nil {
-			return fmt.Errorf("initializing tka: %v", err)
-		}
-		if err := authority.Compact(storage, tkaCompactionDefaults); err != nil {
-			b.logf("tka compaction failed: %v", err)
-		}
-
-		b.tka = &tkaState{
-			profile:   cp.ID(),
-			authority: authority,
-			storage:   storage,
-		}
-		b.logf("tka initialized at head %x", authority.Head())
-	}
-
-	return nil
-}
-
 // resetDialPlan resets the dialPlan for this LocalBackend. It will log if
 // anything is reset.
 //