dendrite/setup/jetstream/nats.go
Neil Alexander 98a5e410d7
Per-room consumers (#2293)
* Roomserver input refactoring — again!

* Ensure the actor runs again

* Preserve consumer after unsubscribe

* Another sprinkling of magic

* Rename `TopicFor` to `Prefixed`

* Recreate the stream if the config is bad

* Check streams too

* Prefix subjects, preserve inboxes

* Recreate if subjects wrong

* Remove stream subject

* Reconstruct properly

* Fix mutex unlock

* Comments

* Fix tests

* Don't drop events

* Review comments

* Separate `queueInputRoomEvents` function

* Re-jig control flow a bit
2022-03-23 10:20:18 +00:00

127 lines
3.6 KiB
Go

package jetstream
import (
"reflect"
"strings"
"sync"
"time"
"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(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(cfg, nc)
}
func setupNATS(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 {
logrus.WithError(err).WithField("stream", name).WithField("subjects", subjects).Fatal("Unable to add stream")
}
}
}
return s, nc
}