WIP all: impl dynamic reconfiguration

internal/aghos/filewalker_internal_test.go

@@ -15,11 +15,11 @@ import (
 // errFSOpen.
 type errFS struct{}
 
-// errFSOpen is returned from errGlobFS.Open.
+// errFSOpen is returned from errFS.Open.
 const errFSOpen errors.Error = "test open error"
 
-// Open implements the fs.FS interface for *errGlobFS.  fsys is always nil and
-// err is always errFSOpen.
+// Open implements the fs.FS interface for *errFS.  fsys is always nil and err
+// is always errFSOpen.
 func (efs *errFS) Open(name string) (fsys fs.File, err error) {
 	return nil, errFSOpen
 }

internal/aghos/os.go

@@ -175,11 +175,21 @@ func RootDirFS() (fsys fs.FS) {
 	return os.DirFS("")
 }
 
+// NotifyReconfigureSignal notifies c on receiving reconfigure signals.
+func NotifyReconfigureSignal(c chan<- os.Signal) {
+	notifyReconfigureSignal(c)
+}
+
 // NotifyShutdownSignal notifies c on receiving shutdown signals.
 func NotifyShutdownSignal(c chan<- os.Signal) {
 	notifyShutdownSignal(c)
 }
 
+// IsReconfigureSignal returns true if sig is a reconfigure signal.
+func IsReconfigureSignal(sig os.Signal) (ok bool) {
+	return isReconfigureSignal(sig)
+}
+
 // IsShutdownSignal returns true if sig is a shutdown signal.
 func IsShutdownSignal(sig os.Signal) (ok bool) {
 	return isShutdownSignal(sig)

internal/aghos/os_unix.go

@@ -9,10 +9,18 @@ import (
 	"golang.org/x/sys/unix"
 )
 
+func notifyReconfigureSignal(c chan<- os.Signal) {
+	signal.Notify(c, unix.SIGHUP)
+}
+
 func notifyShutdownSignal(c chan<- os.Signal) {
 	signal.Notify(c, unix.SIGINT, unix.SIGQUIT, unix.SIGTERM)
 }
 
+func isReconfigureSignal(sig os.Signal) (ok bool) {
+	return sig == unix.SIGHUP
+}
+
 func isShutdownSignal(sig os.Signal) (ok bool) {
 	switch sig {
 	case

internal/aghos/os_windows.go

@@ -39,12 +39,20 @@ func isOpenWrt() (ok bool) {
 	return false
 }
 
+func notifyReconfigureSignal(c chan<- os.Signal) {
+	signal.Notify(c, windows.SIGHUP)
+}
+
 func notifyShutdownSignal(c chan<- os.Signal) {
 	// syscall.SIGTERM is processed automatically.  See go doc os/signal,
 	// section Windows.
 	signal.Notify(c, os.Interrupt)
 }
 
+func isReconfigureSignal(sig os.Signal) (ok bool) {
+	return sig == windows.SIGHUP
+}
+
 func isShutdownSignal(sig os.Signal) (ok bool) {
 	switch sig {
 	case

internal/aghtest/interface.go

@@ -6,6 +6,7 @@ import (
 	"net"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/agh"
 	"github.com/AdguardTeam/dnsproxy/upstream"
 	"github.com/miekg/dns"
 )
@@ -88,7 +89,7 @@ func (l *Listener) Close() (err error) {
 	return l.OnClose()
 }
 
-// Module AdGuardHome
+// Module adguard-home
 
 // Package aghos
 
@@ -117,29 +118,31 @@ func (w *FSWatcher) Close() (err error) {
 	return w.OnClose()
 }
 
-// Package websvc
+// Package agh
 
-// ServiceWithConfig is a mock [websvc.ServiceWithConfig] implementation for
-// tests.
+// type check
+var _ agh.ServiceWithConfig[struct{}] = (*ServiceWithConfig[struct{}])(nil)
+
+// ServiceWithConfig is a mock [agh.ServiceWithConfig] implementation for tests.
 type ServiceWithConfig[ConfigType any] struct {
 	OnStart    func() (err error)
 	OnShutdown func(ctx context.Context) (err error)
 	OnConfig   func() (c ConfigType)
 }
 
-// Start implements the [websvc.ServiceWithConfig] interface for
+// Start implements the [agh.ServiceWithConfig] interface for
 // *ServiceWithConfig.
 func (s *ServiceWithConfig[_]) Start() (err error) {
 	return s.OnStart()
 }
 
-// Shutdown implements the [websvc.ServiceWithConfig] interface for
+// Shutdown implements the [agh.ServiceWithConfig] interface for
 // *ServiceWithConfig.
 func (s *ServiceWithConfig[_]) Shutdown(ctx context.Context) (err error) {
 	return s.OnShutdown(ctx)
 }
 
-// Config implements the [websvc.ServiceWithConfig] interface for
+// Config implements the [agh.ServiceWithConfig] interface for
 // *ServiceWithConfig.
 func (s *ServiceWithConfig[ConfigType]) Config() (c ConfigType) {
 	return s.OnConfig()

internal/aghtest/interface_test.go

@@ -1,9 +1,3 @@
 package aghtest_test
 
-import (
-	"github.com/AdguardTeam/AdGuardHome/internal/aghtest"
-	"github.com/AdguardTeam/AdGuardHome/internal/next/websvc"
-)
-
-// type check
-var _ websvc.ServiceWithConfig[struct{}] = (*aghtest.ServiceWithConfig[struct{}])(nil)
+// Put interface checks that cause import cycles here.

internal/next/agh/agh.go

@@ -1,6 +1,4 @@
 // Package agh contains common entities and interfaces of AdGuard Home.
-//
-// TODO(a.garipov): Move to the upper-level internal/.
 package agh
 
 import "context"
@@ -23,11 +21,43 @@ type Service interface {
 // type check
 var _ Service = EmptyService{}
 
-// EmptyService is a Service that does nothing.
+// EmptyService is a [Service] that does nothing.
+//
+// TODO(a.garipov): Remove if unnecessary.
 type EmptyService struct{}
 
-// Start implements the Service interface for EmptyService.
+// Start implements the [Service] interface for EmptyService.
 func (EmptyService) Start() (err error) { return nil }
 
-// Shutdown implements the Service interface for EmptyService.
+// Shutdown implements the [Service] interface for EmptyService.
 func (EmptyService) Shutdown(_ context.Context) (err error) { return nil }
+
+// ServiceWithConfig is an extension of the [Service] interface for services
+// that can return their configuration.
+//
+// TODO(a.garipov): Consider removing this generic interface if we figure out
+// how to make it testable in a better way.
+type ServiceWithConfig[ConfigType any] interface {
+	Service
+
+	Config() (c ConfigType)
+}
+
+// type check
+var _ ServiceWithConfig[struct{}] = (*EmptyServiceWithConfig[struct{}])(nil)
+
+// EmptyServiceWithConfig is a ServiceWithConfig that does nothing.  Its Config
+// method returns Conf.
+//
+// TODO(a.garipov): Remove if unnecessary.
+type EmptyServiceWithConfig[T any] struct {
+	EmptyService
+
+	Conf T
+}
+
+// Config implements the [ServiceWithConfig] interface for
+// *EmptyServiceWithConfig.
+func (s *EmptyServiceWithConfig[ConfigType]) Config() (conf ConfigType) {
+	return s.Conf
+}

internal/next/cmd/cmd.go

@@ -8,10 +8,11 @@ import (
 	"context"
 	"io/fs"
 	"math/rand"
-	"net/netip"
+	"os"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/internal/next/websvc"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/svc"
+	"github.com/AdguardTeam/AdGuardHome/internal/version"
 	"github.com/AdguardTeam/golibs/log"
 )
 
@@ -24,29 +25,33 @@ func Main(clientBuildFS fs.FS) {
 
 	// TODO(a.garipov): Set up logging.
 
+	log.Info("starting adguard home, version %s, pid %d", version.Version(), os.Getpid())
+
 	// Web Service
 
 	// TODO(a.garipov): Use in the Web service.
 	_ = clientBuildFS
 
-	// TODO(a.garipov): Make configurable.
-	web := websvc.New(&websvc.Config{
-		// TODO(a.garipov): Use an actual implementation.
-		ConfigManager: nil,
-		Addresses:     []netip.AddrPort{netip.MustParseAddrPort("127.0.0.1:3001")},
-		Start:         start,
-		Timeout:       60 * time.Second,
-		ForceHTTPS:    false,
-	})
-
-	err := web.Start()
+	// TODO(a.garipov): Set up configuration file name.
+	const confFile = "AdGuardHome.1.yaml"
+
+	confMgr, err := svc.New(confFile, start)
+	fatalOnError(err)
+
+	web := confMgr.Web()
+	err = web.Start()
+	fatalOnError(err)
+
+	dns := confMgr.DNS()
+	err = dns.Start()
 	fatalOnError(err)
 
 	sigHdlr := newSignalHandler(
 		web,
+		dns,
 	)
 
-	go sigHdlr.handle()
+	go sigHdlr.handle(confFile, start)
 
 	select {}
 }

internal/next/cmd/signal.go

@@ -2,9 +2,11 @@ package cmd
 
 import (
 	"os"
+	"time"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
 	"github.com/AdguardTeam/AdGuardHome/internal/next/agh"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/svc"
 	"github.com/AdguardTeam/golibs/log"
 )
 
@@ -18,26 +20,57 @@ type signalHandler struct {
 }
 
 // handle processes OS signals.
-func (h *signalHandler) handle() {
+func (h *signalHandler) handle(confFile string, start time.Time) {
 	defer log.OnPanic("signalHandler.handle")
 
 	for sig := range h.signal {
 		log.Info("sighdlr: received signal %q", sig)
 
-		if aghos.IsShutdownSignal(sig) {
-			h.shutdown()
+		if aghos.IsReconfigureSignal(sig) {
+			h.reconfigure(confFile, start)
+		} else if aghos.IsShutdownSignal(sig) {
+			h.shutdown(true)
 		}
 	}
 }
 
+// reconfigure rereads the configuration file and updates and restarts services.
+func (h *signalHandler) reconfigure(confFile string, start time.Time) {
+	log.Info("sighdlr: reconfiguring adguard home")
+
+	h.shutdown(false)
+
+	// TODO(a.garipov): This is a very rough way to do it.  Some services can be
+	// reconfigured without the full shutdown, and the error handling is
+	// currently not the best.
+
+	confMgr, err := svc.New(confFile, start)
+	fatalOnError(err)
+
+	web := confMgr.Web()
+	err = web.Start()
+	fatalOnError(err)
+
+	dns := confMgr.DNS()
+	err = dns.Start()
+	fatalOnError(err)
+
+	h.services = []agh.Service{
+		dns,
+		web,
+	}
+
+	log.Info("sighdlr: successfully reconfigured adguard home")
+}
+
 // Exit status constants.
 const (
 	statusSuccess = 0
 	statusError   = 1
 )
 
 // shutdown gracefully shuts down all services.
-func (h *signalHandler) shutdown() {
+func (h *signalHandler) shutdown(shouldExit bool) {
 	ctx, cancel := ctxWithDefaultTimeout()
 	defer cancel()
 
@@ -54,7 +87,11 @@ func (h *signalHandler) shutdown() {
 
 	log.Info("sighdlr: shutting down adguard home")
 
-	os.Exit(status)
+	if shouldExit {
+		log.Info("sighdlr: exiting with status %d", status)
+
+		os.Exit(status)
+	}
 }
 
 // newSignalHandler returns a new signalHandler that shuts down svcs.
@@ -65,6 +102,7 @@ func newSignalHandler(svcs ...agh.Service) (h *signalHandler) {
 	}
 
 	aghos.NotifyShutdownSignal(h.signal)
+	aghos.NotifyReconfigureSignal(h.signal)
 
 	return h
 }

internal/next/svc/config.go

@@ -0,0 +1,40 @@
+package svc
+
+import (
+	"net/netip"
+
+	"github.com/AdguardTeam/golibs/timeutil"
+)
+
+// Configuration Structures
+
+// config is the top-level on-disk configuration structure.
+type config struct {
+	DNS  *dnsConfig  `yaml:"dns"`
+	HTTP *httpConfig `yaml:"http"`
+	// TODO(a.garipov): Use.
+	SchemaVersion int `yaml:"schema_version"`
+	// TODO(a.garipov): Use.
+	DebugPprof bool `yaml:"debug_pprof"`
+	Verbose    bool `yaml:"verbose"`
+}
+
+// dnsConfig is the on-disk DNS configuration.
+//
+// TODO(a.garipov): Validate.
+type dnsConfig struct {
+	Addresses       []netip.AddrPort  `yaml:"addresses"`
+	BootstrapDNS    []string          `yaml:"bootstrap_dns"`
+	UpstreamDNS     []string          `yaml:"upstream_dns"`
+	UpstreamTimeout timeutil.Duration `yaml:"upstream_timeout"`
+}
+
+// httpConfig is the on-disk web API configuration.
+//
+// TODO(a.garipov): Validate.
+type httpConfig struct {
+	Addresses       []netip.AddrPort  `yaml:"addresses"`
+	SecureAddresses []netip.AddrPort  `yaml:"secure_addresses"`
+	Timeout         timeutil.Duration `yaml:"timeout"`
+	ForceHTTPS      bool              `yaml:"force_https"`
+}