package jetstream import ( "fmt" "reflect" "strings" "sync" "time" "github.com/getsentry/sentry-go" "github.com/matrix-org/dendrite/setup/config" "github.com/matrix-org/dendrite/setup/process" "github.com/sirupsen/logrus" natsserver "github.com/nats-io/nats-server/v2/server" natsclient "github.com/nats-io/nats.go" ) var natsServer *natsserver.Server var natsServerMutex sync.Mutex func Prepare(process *process.ProcessContext, cfg *config.JetStream) (natsclient.JetStreamContext, *natsclient.Conn) { // check if we need an in-process NATS Server if len(cfg.Addresses) != 0 { return setupNATS(process, cfg, nil) } natsServerMutex.Lock() if natsServer == nil { var err error natsServer, err = natsserver.NewServer(&natsserver.Options{ ServerName: "monolith", DontListen: true, JetStream: true, StoreDir: string(cfg.StoragePath), NoSystemAccount: true, MaxPayload: 16 * 1024 * 1024, }) if err != nil { panic(err) } natsServer.ConfigureLogger() go func() { process.ComponentStarted() natsServer.Start() }() go func() { <-process.WaitForShutdown() natsServer.Shutdown() natsServer.WaitForShutdown() process.ComponentFinished() }() } natsServerMutex.Unlock() if !natsServer.ReadyForConnections(time.Second * 10) { logrus.Fatalln("NATS did not start in time") } nc, err := natsclient.Connect("", natsclient.InProcessServer(natsServer)) if err != nil { logrus.Fatalln("Failed to create NATS client") } return setupNATS(process, cfg, nc) } func setupNATS(process *process.ProcessContext, cfg *config.JetStream, nc *natsclient.Conn) (natsclient.JetStreamContext, *natsclient.Conn) { if nc == nil { var err error nc, err = natsclient.Connect(strings.Join(cfg.Addresses, ",")) if err != nil { logrus.WithError(err).Panic("Unable to connect to NATS") return nil, nil } } s, err := nc.JetStream() if err != nil { logrus.WithError(err).Panic("Unable to get JetStream context") return nil, nil } for _, stream := range streams { // streams are defined in streams.go name := cfg.Prefixed(stream.Name) info, err := s.StreamInfo(name) if err != nil && err != natsclient.ErrStreamNotFound { logrus.WithError(err).Fatal("Unable to get stream info") } subjects := stream.Subjects if len(subjects) == 0 { // By default we want each stream to listen for the subjects // that are either an exact match for the stream name, or where // the first part of the subject is the stream name. ">" is a // wildcard in NATS for one or more subject tokens. In the case // that the stream is called "Foo", this will match any message // with the subject "Foo", "Foo.Bar" or "Foo.Bar.Baz" etc. subjects = []string{name, name + ".>"} } if info != nil { switch { case !reflect.DeepEqual(info.Config.Subjects, subjects): fallthrough case info.Config.Retention != stream.Retention: fallthrough case info.Config.Storage != stream.Storage: if err = s.DeleteStream(name); err != nil { logrus.WithError(err).Fatal("Unable to delete stream") } info = nil } } if info == nil { // If we're trying to keep everything in memory (e.g. unit tests) // then overwrite the storage policy. if cfg.InMemory { stream.Storage = natsclient.MemoryStorage } // Namespace the streams without modifying the original streams // array, otherwise we end up with namespaces on namespaces. namespaced := *stream namespaced.Name = name namespaced.Subjects = subjects if _, err = s.AddStream(&namespaced); err != nil { logger := logrus.WithError(err).WithFields(logrus.Fields{ "stream": namespaced.Name, "subjects": namespaced.Subjects, }) // If the stream was supposed to be in-memory to begin with // then an error here is fatal so we'll give up. if namespaced.Storage == natsclient.MemoryStorage { logger.WithError(err).Fatal("Unable to add in-memory stream") } // The stream was supposed to be on disk. Let's try starting // Dendrite with the stream in-memory instead. That'll mean that // we can't recover anything that was queued on the disk but we // will still be able to start and run hopefully in the meantime. logger.WithError(err).Error("Unable to add stream") sentry.CaptureException(fmt.Errorf("Unable to add stream %q: %w", namespaced.Name, err)) namespaced.Storage = natsclient.MemoryStorage if _, err = s.AddStream(&namespaced); err != nil { // We tried to add the stream in-memory instead but something // went wrong. That's an unrecoverable situation so we will // give up at this point. logger.WithError(err).Fatal("Unable to add in-memory stream") } if stream.Storage != namespaced.Storage { // We've managed to add the stream in memory. What's on the // disk will be left alone, but our ability to recover from a // future crash will be limited. Yell about it. sentry.CaptureException(fmt.Errorf("Stream %q is running in-memory; this may be due to data corruption in the JetStream storage directory, investigate as soon as possible", namespaced.Name)) logrus.Warn("Stream is running in-memory; this may be due to data corruption in the JetStream storage directory, investigate as soon as possible") process.Degraded() } } } } return s, nc }