added nats + worker modules

nats/nats.go

@@ -0,0 +1,68 @@
+package nats
+
+import (
+	"time"
+
+	"github.com/nats-io/nats-server/v2/server"
+	"github.com/nats-io/nats.go"
+)
+
+func New(opts ...Option) (*nats.Conn, func(), error) {
+	cfg := &config{
+		readyTimeout: 5 * time.Second,
+	}
+
+	for _, opt := range opts {
+		opt(cfg)
+	}
+
+	var nc *nats.Conn
+	var shutdown func()
+
+	if cfg.externalURL != "" {
+		var err error
+		nc, err = nats.Connect(cfg.externalURL, cfg.connectOpts...)
+		if err != nil {
+			return nil, nil, err
+		}
+		shutdown = func() { nc.Close() }
+		return nc, shutdown, nil
+	}
+
+	serverOpts := cfg.serverOpts
+	if serverOpts == nil {
+		serverOpts = &server.Options{
+			Host:  "127.0.0.1",
+			Port:  -1,
+			NoLog: true,
+		}
+	}
+
+	s, err := server.NewServer(serverOpts)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	go s.Start()
+
+	if !s.ReadyForConnections(cfg.readyTimeout) {
+		s.Shutdown()
+		return nil, nil, ErrNotReady
+	}
+
+	nc, err = nats.Connect(
+		s.ClientURL(),
+		append(cfg.connectOpts, nats.InProcessServer(s), nats.Name("embedded-client"))...,
+	)
+	if err != nil {
+		s.Shutdown()
+		return nil, nil, err
+	}
+
+	shutdown = func() {
+		nc.Close()
+		s.Shutdown()
+	}
+
+	return nc, shutdown, nil
+}