Split code into modules

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>

cmd/headscale/cli/routes.go

@@ -7,7 +7,7 @@ import (
 	"strconv"
 
 	v1 "github.com/juanfont/headscale/gen/go/headscale/v1"
-	"github.com/juanfont/headscale/hscontrol"
+	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/pterm/pterm"
 	"github.com/spf13/cobra"
 	"google.golang.org/grpc/status"
@@ -277,7 +277,7 @@ func routesToPtables(routes []*v1.Route) pterm.TableData {
 
 			continue
 		}
-		if prefix == hscontrol.ExitRouteV4 || prefix == hscontrol.ExitRouteV6 {
+		if prefix == types.ExitRouteV4 || prefix == types.ExitRouteV6 {
 			isPrimaryStr = "-"
 		} else {
 			isPrimaryStr = strconv.FormatBool(route.IsPrimary)

cmd/headscale/cli/utils.go

@@ -10,6 +10,7 @@ import (
 
 	v1 "github.com/juanfont/headscale/gen/go/headscale/v1"
 	"github.com/juanfont/headscale/hscontrol"
+	"github.com/juanfont/headscale/hscontrol/policy"
 	"github.com/juanfont/headscale/hscontrol/util"
 	"github.com/rs/zerolog/log"
 	"google.golang.org/grpc"
@@ -41,13 +42,15 @@ func getHeadscaleApp() (*hscontrol.Headscale, error) {
 
 	if cfg.ACL.PolicyPath != "" {
 		aclPath := util.AbsolutePathFromConfigPath(cfg.ACL.PolicyPath)
-		err = app.LoadACLPolicyFromPath(aclPath)
+		pol, err := policy.LoadACLPolicyFromPath(aclPath)
 		if err != nil {
 			log.Fatal().
 				Str("path", aclPath).
 				Err(err).
 				Msg("Could not load the ACL policy")
 		}
+
+		app.ACLPolicy = pol
 	}
 
 	return app, nil

hscontrol/api.go

@@ -18,9 +18,6 @@ const (
 	// TODO(juan): remove this once https://github.com/juanfont/headscale/issues/727 is fixed.
 	registrationHoldoff        = time.Second * 5
 	reservedResponseHeaderSize = 4
-	RegisterMethodAuthKey      = "authkey"
-	RegisterMethodOIDC         = "oidc"
-	RegisterMethodCLI          = "cli"
 )
 
 var ErrRegisterMethodCLIDoesNotSupportExpire = errors.New(
@@ -56,7 +53,7 @@ func (h *Headscale) HealthHandler(
 		}
 	}
 
-	if err := h.db.pingDB(req.Context()); err != nil {
+	if err := h.db.PingDB(req.Context()); err != nil {
 		respond(err)
 
 		return

hscontrol/api_common.go

@@ -3,20 +3,21 @@ package hscontrol
 import (
 	"time"
 
+	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/juanfont/headscale/hscontrol/util"
 	"github.com/rs/zerolog/log"
 	"tailscale.com/tailcfg"
 )
 
 func (h *Headscale) generateMapResponse(
 	mapRequest tailcfg.MapRequest,
-	machine *Machine,
+	machine *types.Machine,
 ) (*tailcfg.MapResponse, error) {
 	log.Trace().
 		Str("func", "generateMapResponse").
 		Str("machine", mapRequest.Hostinfo.Hostname).
 		Msg("Creating Map response")
-	node, err := h.db.toNode(*machine, h.aclPolicy, h.cfg.BaseDomain, h.cfg.DNSConfig)
+	node, err := h.db.TailNode(*machine, h.ACLPolicy, h.cfg.DNSConfig)
 	if err != nil {
 		log.Error().
 			Caller().
@@ -27,7 +28,7 @@ func (h *Headscale) generateMapResponse(
 		return nil, err
 	}
 
-	peers, err := h.db.getValidPeers(h.aclPolicy, h.aclRules, machine)
+	peers, err := h.db.GetValidPeers(h.aclRules, machine)
 	if err != nil {
 		log.Error().
 			Caller().
@@ -38,9 +39,9 @@ func (h *Headscale) generateMapResponse(
 		return nil, err
 	}
 
-	profiles := h.db.getMapResponseUserProfiles(*machine, peers)
+	profiles := h.db.GetMapResponseUserProfiles(*machine, peers)
 
-	nodePeers, err := h.db.toNodes(peers, h.aclPolicy, h.cfg.BaseDomain, h.cfg.DNSConfig)
+	nodePeers, err := h.db.TailNodes(peers, h.ACLPolicy, h.cfg.DNSConfig)
 	if err != nil {
 		log.Error().
 			Caller().