chore(settings): refactor settings processing (#756)

- Better settings tree structure logged using `qdm12/gotree`
- Read settings from environment variables, then files, then secret files
- Settings methods to default them, merge them and override them
- `DNS_PLAINTEXT_ADDRESS` default changed to `127.0.0.1` to use DoT. Warning added if set to something else.
- `HTTPPROXY_LISTENING_ADDRESS` instead of `HTTPPROXY_PORT` (with retro-compatibility)

internal/httpproxy/loop.go

@@ -5,7 +5,7 @@ import (
 	"context"
 	"time"
 
-	"github.com/qdm12/gluetun/internal/configuration"
+	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/httpproxy/state"
 	"github.com/qdm12/gluetun/internal/loopstate"
@@ -36,7 +36,7 @@ type Loop struct {
 
 const defaultBackoffTime = 10 * time.Second
 
-func NewLoop(logger Logger, settings configuration.HTTPProxy) *Loop {
+func NewLoop(logger Logger, settings settings.HTTPProxy) *Loop {
 	start := make(chan struct{})
 	running := make(chan models.LoopStatus)
 	stop := make(chan struct{})

internal/httpproxy/run.go

@@ -2,7 +2,6 @@ package httpproxy
 
 import (
 	"context"
-	"strconv"
 
 	"github.com/qdm12/gluetun/internal/constants"
 )
@@ -14,7 +13,7 @@ type Runner interface {
 func (l *Loop) Run(ctx context.Context, done chan<- struct{}) {
 	defer close(done)
 
-	if !l.state.GetSettings().Enabled {
+	if !*l.state.GetSettings().Enabled {
 		select {
 		case <-l.start:
 		case <-ctx.Done():
@@ -26,8 +25,9 @@ func (l *Loop) Run(ctx context.Context, done chan<- struct{}) {
 		runCtx, runCancel := context.WithCancel(ctx)
 
 		settings := l.state.GetSettings()
-		address := ":" + strconv.Itoa(int(settings.Port))
-		server := New(runCtx, address, l.logger, settings.Stealth, settings.Log, settings.User, settings.Password)
+		server := New(runCtx, settings.ListeningAddress, l.logger,
+			*settings.Stealth, *settings.Log, *settings.User,
+			*settings.Password)
 
 		errorCh := make(chan error)
 		go server.Run(runCtx, errorCh)

internal/httpproxy/settings.go

@@ -3,17 +3,17 @@ package httpproxy
 import (
 	"context"
 
-	"github.com/qdm12/gluetun/internal/configuration"
+	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/httpproxy/state"
 )
 
 type SettingsGetSetter = state.SettingsGetSetter
 
-func (l *Loop) GetSettings() (settings configuration.HTTPProxy) {
+func (l *Loop) GetSettings() (settings settings.HTTPProxy) {
 	return l.state.GetSettings()
 }
 
-func (l *Loop) SetSettings(ctx context.Context, settings configuration.HTTPProxy) (
+func (l *Loop) SetSettings(ctx context.Context, settings settings.HTTPProxy) (
 	outcome string) {
 	return l.state.SetSettings(ctx, settings)
 }

internal/httpproxy/state/settings.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"reflect"
 
-	"github.com/qdm12/gluetun/internal/configuration"
+	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/constants"
 )
 
@@ -14,10 +14,10 @@ type SettingsGetSetter interface {
 }
 
 type SettingsGetter interface {
-	GetSettings() (settings configuration.HTTPProxy)
+	GetSettings() (settings settings.HTTPProxy)
 }
 
-func (s *State) GetSettings() (settings configuration.HTTPProxy) {
+func (s *State) GetSettings() (settings settings.HTTPProxy) {
 	s.settingsMu.RLock()
 	defer s.settingsMu.RUnlock()
 	return s.settings
@@ -25,19 +25,19 @@ func (s *State) GetSettings() (settings configuration.HTTPProxy) {
 
 type SettingsSetter interface {
 	SetSettings(ctx context.Context,
-		settings configuration.HTTPProxy) (outcome string)
+		settings settings.HTTPProxy) (outcome string)
 }
 
 func (s *State) SetSettings(ctx context.Context,
-	settings configuration.HTTPProxy) (outcome string) {
+	settings settings.HTTPProxy) (outcome string) {
 	s.settingsMu.Lock()
 	settingsUnchanged := reflect.DeepEqual(settings, s.settings)
 	if settingsUnchanged {
 		s.settingsMu.Unlock()
 		return "settings left unchanged"
 	}
-	newEnabled := settings.Enabled
-	previousEnabled := s.settings.Enabled
+	newEnabled := *settings.Enabled
+	previousEnabled := *s.settings.Enabled
 	s.settings = settings
 	s.settingsMu.Unlock()
 	// Either restart or set changed status

internal/httpproxy/state/state.go

@@ -3,7 +3,7 @@ package state
 import (
 	"sync"
 
-	"github.com/qdm12/gluetun/internal/configuration"
+	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/loopstate"
 )
 
@@ -14,7 +14,7 @@ type Manager interface {
 }
 
 func New(statusApplier loopstate.Applier,
-	settings configuration.HTTPProxy) *State {
+	settings settings.HTTPProxy) *State {
 	return &State{
 		statusApplier: statusApplier,
 		settings:      settings,
@@ -23,6 +23,6 @@ func New(statusApplier loopstate.Applier,
 
 type State struct {
 	statusApplier loopstate.Applier
-	settings      configuration.HTTPProxy
+	settings      settings.HTTPProxy
 	settingsMu    sync.RWMutex
 }