added nats + worker modules

nats/errors.go

@@ -0,0 +1,5 @@
+package nats
+
+import "errors"
+
+var ErrNotReady = errors.New("nats server not ready after ready check timeout")

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
+}

nats/options.go

@@ -0,0 +1,74 @@
+package nats
+
+import (
+	"strings"
+	"time"
+
+	"github.com/nats-io/nats-server/v2/server"
+	"github.com/nats-io/nats.go"
+)
+
+type Option func(*config)
+
+type config struct {
+	serverOpts      *server.Options
+	connectOpts     []nats.Option
+	externalURL     string
+	readyTimeout    time.Duration
+	shutdownTimeout time.Duration
+}
+
+func WithExternalURL(url string) Option {
+	return func(c *config) { c.externalURL = url }
+}
+
+func WithServerOpts(opts *server.Options) Option {
+	return func(c *config) { c.serverOpts = opts }
+}
+
+func WithConnectOpts(opts ...nats.Option) Option {
+	return func(c *config) { c.connectOpts = append(c.connectOpts, opts...) }
+}
+
+func WithReadyTimeout(d time.Duration) Option {
+	return func(c *config) { c.readyTimeout = d }
+}
+
+func WithCluster(name string, routes []string) Option {
+	return func(c *config) {
+		if c.serverOpts == nil {
+			c.serverOpts = &server.Options{}
+		}
+		c.serverOpts.Cluster = server.ClusterOpts{
+			Name: name,
+		}
+		c.serverOpts.Routes = server.RoutesFromStr(strings.Join(routes, ","))
+	}
+}
+
+func WithClusterListen() Option {
+	return func(c *config) {
+		if c.serverOpts == nil {
+			c.serverOpts = &server.Options{}
+		}
+		c.serverOpts.Cluster.ListenStr = "0.0.0.0:6222"
+	}
+}
+
+func WithJetStream(enabled bool, storeDir ...string) Option {
+	return func(c *config) {
+		if c.serverOpts == nil {
+			c.serverOpts = &server.Options{}
+		}
+		c.serverOpts.JetStream = enabled
+		if len(storeDir) > 0 {
+			c.serverOpts.StoreDir = storeDir[0]
+		}
+	}
+}
+
+func WithClientName(name string) Option {
+	return func(c *config) {
+		c.connectOpts = append(c.connectOpts, nats.Name(name))
+	}
+}