feat(GODT-2814): Standalone Server Manager

Convert ServerManger into a standalone service so that it can become a
self contained module.

internal/services/imapsmtpserver/imap.go

@@ -0,0 +1,194 @@
+// Copyright (c) 2023 Proton AG
+//
+// This file is part of Proton Mail Bridge.
+//
+// Proton Mail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Proton Mail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Proton Mail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package imapsmtpserver
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/Masterminds/semver/v3"
+	"github.com/ProtonMail/gluon"
+	"github.com/ProtonMail/gluon/async"
+	imapEvents "github.com/ProtonMail/gluon/events"
+	"github.com/ProtonMail/gluon/imap"
+	"github.com/ProtonMail/gluon/reporter"
+	"github.com/ProtonMail/gluon/store"
+	"github.com/ProtonMail/gluon/store/fallback_v0"
+	"github.com/ProtonMail/proton-bridge/v3/internal/constants"
+	"github.com/ProtonMail/proton-bridge/v3/internal/files"
+	"github.com/ProtonMail/proton-bridge/v3/internal/logging"
+	"github.com/sirupsen/logrus"
+)
+
+type IMAPSettingsProvider interface {
+	TLSConfig() *tls.Config
+	LogClient() bool
+	LogServer() bool
+	Port() int
+	SetPort(int) error
+	UseSSL() bool
+	CacheDirectory() string
+	DataDirectory() (string, error)
+	SetCacheDirectory(string) error
+	EventPublisher() IMAPEventPublisher
+	Version() *semver.Version
+}
+
+type IMAPEventPublisher interface {
+	PublishIMAPEvent(ctx context.Context, event imapEvents.Event)
+}
+
+func ApplyGluonCachePathSuffix(basePath string) string {
+	return filepath.Join(basePath, "backend", "store")
+}
+
+func ApplyGluonConfigPathSuffix(basePath string) string {
+	return filepath.Join(basePath, "backend", "db")
+}
+
+func newIMAPServer(
+	gluonCacheDir, gluonConfigDir string,
+	version *semver.Version,
+	tlsConfig *tls.Config,
+	reporter reporter.Reporter,
+	logClient, logServer bool,
+	eventPublisher IMAPEventPublisher,
+	tasks *async.Group,
+	uidValidityGenerator imap.UIDValidityGenerator,
+	panicHandler async.PanicHandler,
+) (*gluon.Server, error) {
+	gluonCacheDir = ApplyGluonCachePathSuffix(gluonCacheDir)
+	gluonConfigDir = ApplyGluonConfigPathSuffix(gluonConfigDir)
+
+	logrus.WithFields(logrus.Fields{
+		"gluonStore": gluonCacheDir,
+		"gluonDB":    gluonConfigDir,
+		"version":    version,
+		"logClient":  logClient,
+		"logServer":  logServer,
+	}).Info("Creating IMAP server")
+
+	if logClient || logServer {
+		log := logrus.WithField("protocol", "IMAP")
+		log.Warning("================================================")
+		log.Warning("THIS LOG WILL CONTAIN **DECRYPTED** MESSAGE DATA")
+		log.Warning("================================================")
+	}
+
+	var imapClientLog io.Writer
+
+	if logClient {
+		imapClientLog = logging.NewIMAPLogger()
+	} else {
+		imapClientLog = io.Discard
+	}
+
+	var imapServerLog io.Writer
+
+	if logServer {
+		imapServerLog = logging.NewIMAPLogger()
+	} else {
+		imapServerLog = io.Discard
+	}
+
+	imapServer, err := gluon.New(
+		gluon.WithTLS(tlsConfig),
+		gluon.WithDataDir(gluonCacheDir),
+		gluon.WithDatabaseDir(gluonConfigDir),
+		gluon.WithStoreBuilder(new(storeBuilder)),
+		gluon.WithLogger(imapClientLog, imapServerLog),
+		getGluonVersionInfo(version),
+		gluon.WithReporter(reporter),
+		gluon.WithUIDValidityGenerator(uidValidityGenerator),
+		gluon.WithPanicHandler(panicHandler),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	tasks.Once(func(ctx context.Context) {
+		watcher := imapServer.AddWatcher()
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case e, ok := <-watcher:
+				if !ok {
+					return
+				}
+
+				eventPublisher.PublishIMAPEvent(ctx, e)
+			}
+		}
+	})
+
+	tasks.Once(func(ctx context.Context) {
+		async.RangeContext(ctx, imapServer.GetErrorCh(), func(err error) {
+			logrus.WithError(err).Error("IMAP server error")
+		})
+	})
+
+	return imapServer, nil
+}
+
+func getGluonVersionInfo(version *semver.Version) gluon.Option {
+	return gluon.WithVersionInfo(
+		int(version.Major()),
+		int(version.Minor()),
+		int(version.Patch()),
+		constants.FullAppName,
+		"TODO",
+		"TODO",
+	)
+}
+
+type storeBuilder struct{}
+
+func (*storeBuilder) New(path, userID string, passphrase []byte) (store.Store, error) {
+	return store.NewOnDiskStore(
+		filepath.Join(path, userID),
+		passphrase,
+		store.WithFallback(fallback_v0.NewOnDiskStoreV0WithCompressor(&fallback_v0.GZipCompressor{})),
+	)
+}
+
+func (*storeBuilder) Delete(path, userID string) error {
+	return os.RemoveAll(filepath.Join(path, userID))
+}
+
+func moveGluonCacheDir(settings IMAPSettingsProvider, oldGluonDir, newGluonDir string) error {
+	logrus.Infof("gluon cache moving from %s to %s", oldGluonDir, newGluonDir)
+	oldCacheDir := ApplyGluonCachePathSuffix(oldGluonDir)
+	if err := files.CopyDir(oldCacheDir, ApplyGluonCachePathSuffix(newGluonDir)); err != nil {
+		return fmt.Errorf("failed to copy gluon dir: %w", err)
+	}
+
+	if err := settings.SetCacheDirectory(newGluonDir); err != nil {
+		return fmt.Errorf("failed to set new gluon cache dir: %w", err)
+	}
+
+	if err := os.RemoveAll(oldCacheDir); err != nil {
+		logrus.WithError(err).Error("failed to remove old gluon cache dir")
+	}
+
+	return nil
+}