This commits removes the locks used to guard data integrity for the
database and replaces them with Transactions, turns out that SQL had
a way to deal with this all along.
This reduces the complexity we had with multiple locks that might stack
or recurse (database, nofitifer, mapper). All notifications and state
updates are now triggered _after_ a database change.
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
This is a massive commit that restructures the code into modules:
db/
All functions related to modifying the Database
types/
All type definitions and methods that can be exclusivly used on
these types without dependencies
policy/
All Policy related code, now without dependencies on the Database.
policy/matcher/
Dedicated code to match machines in a list of FilterRules
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
