Maint: split Go files in dns package

internal/dns/run.go

@@ -0,0 +1,97 @@
+package dns
+
+import (
+	"context"
+	"errors"
+
+	"github.com/qdm12/gluetun/internal/constants"
+)
+
+func (l *looper) Run(ctx context.Context, done chan<- struct{}) {
+	defer close(done)
+
+	const fallback = false
+	l.useUnencryptedDNS(fallback) // TODO remove? Use default DNS by default for Docker resolution?
+	// TODO this one is kept if DNS_KEEP_NAMESERVER=on and should be replaced
+
+	select {
+	case <-l.start:
+	case <-ctx.Done():
+		return
+	}
+
+	for ctx.Err() == nil {
+		// Upper scope variables for Unbound only
+		// Their values are to be used if DOT=off
+		waitError := make(chan error)
+		unboundCancel := func() { waitError <- nil }
+		closeStreams := func() {}
+
+		for l.GetSettings().Enabled {
+			var err error
+			unboundCancel, waitError, closeStreams, err = l.setupUnbound(ctx)
+			if err == nil {
+				l.backoffTime = defaultBackoffTime
+				l.logger.Info("ready")
+				l.signalOrSetStatus(constants.Running)
+				break
+			}
+
+			l.signalOrSetStatus(constants.Crashed)
+
+			if ctx.Err() != nil {
+				return
+			}
+
+			if !errors.Is(err, errUpdateFiles) {
+				const fallback = true
+				l.useUnencryptedDNS(fallback)
+			}
+			l.logAndWait(ctx, err)
+		}
+
+		if !l.GetSettings().Enabled {
+			const fallback = false
+			l.useUnencryptedDNS(fallback)
+		}
+
+		l.userTrigger = false
+
+		stayHere := true
+		for stayHere {
+			select {
+			case <-ctx.Done():
+				unboundCancel()
+				<-waitError
+				close(waitError)
+				closeStreams()
+				return
+			case <-l.stop:
+				l.userTrigger = true
+				l.logger.Info("stopping")
+				const fallback = false
+				l.useUnencryptedDNS(fallback)
+				unboundCancel()
+				<-waitError
+				// do not close waitError or the waitError
+				// select case will trigger
+				closeStreams()
+				l.stopped <- struct{}{}
+			case <-l.start:
+				l.userTrigger = true
+				l.logger.Info("starting")
+				stayHere = false
+			case err := <-waitError: // unexpected error
+				close(waitError)
+				closeStreams()
+
+				unboundCancel()
+				l.state.SetStatus(constants.Crashed)
+				const fallback = true
+				l.useUnencryptedDNS(fallback)
+				l.logAndWait(ctx, err)
+				stayHere = false
+			}
+		}
+	}
+}