From 3a60056bb3c45325d283309ee300f307068cb1ec Mon Sep 17 00:00:00 2001
From: Willy Kloucek <wkloucek@owncloud.com>
Date: Fri, 18 Feb 2022 11:44:26 +0100
Subject: [PATCH] transfer logic into nats server package

---
 nats/pkg/command/server.go      | 50 +++++++------------------------
 nats/pkg/server/nats/nats.go    | 52 ++++++++++++++++++++++++++++-----
 nats/pkg/server/nats/options.go | 16 ++++------
 3 files changed, 61 insertions(+), 57 deletions(-)

diff --git a/nats/pkg/command/server.go b/nats/pkg/command/server.go
index f12538ab6..be2e0ff46 100644
--- a/nats/pkg/command/server.go
+++ b/nats/pkg/command/server.go
@@ -3,7 +3,6 @@ package command
 import (
 	"context"
 	"fmt"
-	"time"
 
 	"github.com/oklog/run"
 
@@ -12,9 +11,6 @@ import (
 	"github.com/owncloud/ocis/nats/pkg/logging"
 	"github.com/owncloud/ocis/nats/pkg/server/nats"
 	"github.com/urfave/cli/v2"
-
-	// TODO: .Logger Option on events/server would make this import redundant
-	stanServer "github.com/nats-io/nats-streaming-server/server"
 )
 
 // Server is the entrypoint for the server command.
@@ -39,46 +35,22 @@ func Server(cfg *config.Config) *cli.Command {
 
 			defer cancel()
 
-			var natsServer *stanServer.StanServer
+			natsServer, err := nats.NewNATSServer(
+				nats.Host(cfg.Nats.Host),
+				nats.Port(cfg.Nats.Port),
+				nats.Logger(logging.NewLogWrapper(logger)),
+			)
+			if err != nil {
+				return err
+			}
 
 			gr.Add(func() error {
-				var err error
-
-				natsServer, err = nats.RunNatsServer(
-					nats.Host(cfg.Nats.Host),
-					nats.Port(cfg.Nats.Port),
-					nats.StanOpts(
-						func(o *stanServer.Options) {
-							o.CustomLogger = logging.NewLogWrapper(logger)
-						},
-					),
-				)
-
-				if err != nil {
-					return err
-				}
-
-				errChan := make(chan error)
-
-				go func() {
-					for {
-						// check if NATs server has an encountered an error
-						if err := natsServer.LastError(); err != nil {
-							errChan <- err
-							return
-						}
-						if ctx.Err() != nil {
-							return // context closed
-						}
-						time.Sleep(1 * time.Second)
-					}
-				}()
-
+				err := make(chan error)
 				select {
 				case <-ctx.Done():
 					return nil
-				case err = <-errChan:
-					return err
+				case err <- natsServer.ListenAndServe():
+					return <-err
 				}
 
 			}, func(_ error) {
diff --git a/nats/pkg/server/nats/nats.go b/nats/pkg/server/nats/nats.go
index 398a4c966..4defe9eed 100644
--- a/nats/pkg/server/nats/nats.go
+++ b/nats/pkg/server/nats/nats.go
@@ -1,17 +1,55 @@
 package nats
 
 import (
+	"time"
+
+	natsServer "github.com/nats-io/nats-server/v2/server"
 	stanServer "github.com/nats-io/nats-streaming-server/server"
 )
 
-// RunNatsServer runs the nats streaming server
-func RunNatsServer(opts ...Option) (*stanServer.StanServer, error) {
-	natsOpts := stanServer.DefaultNatsServerOptions
-	stanOpts := stanServer.GetDefaultOptions()
+type NATSServer struct {
+	natsOpts *natsServer.Options
+	stanOpts *stanServer.Options
+
+	server *stanServer.StanServer
+}
+
+func NewNATSServer(opts ...Option) (*NATSServer, error) {
+	server := &NATSServer{
+		natsOpts: &stanServer.DefaultNatsServerOptions,
+		stanOpts: stanServer.GetDefaultOptions(),
+	}
 
 	for _, o := range opts {
-		o(&natsOpts, stanOpts)
+		o(server.natsOpts, server.stanOpts)
 	}
-	s, err := stanServer.RunServerWithOpts(stanOpts, &natsOpts)
-	return s, err
+
+	return server, nil
+}
+
+func (n *NATSServer) ListenAndServe() (err error) {
+
+	n.server, err = stanServer.RunServerWithOpts(
+		n.stanOpts,
+		n.natsOpts,
+	)
+	if err != nil {
+		return err
+	}
+
+	for {
+		// check if NATs server has an encountered an error
+		if err := n.server.LastError(); err != nil {
+			return err
+		}
+		// check if th NATs server is still running
+		if n.server.State() == stanServer.Shutdown {
+			return nil
+		}
+		time.Sleep(1 * time.Second)
+	}
+}
+
+func (n *NATSServer) Shutdown() {
+	n.server.Shutdown()
 }
diff --git a/nats/pkg/server/nats/options.go b/nats/pkg/server/nats/options.go
index 74e54e51f..0189141ca 100644
--- a/nats/pkg/server/nats/options.go
+++ b/nats/pkg/server/nats/options.go
@@ -2,6 +2,7 @@ package nats
 
 import (
 	natsServer "github.com/nats-io/nats-server/v2/server"
+	"github.com/nats-io/nats-streaming-server/logger"
 	stanServer "github.com/nats-io/nats-streaming-server/server"
 )
 
@@ -22,16 +23,9 @@ func Port(port int) Option {
 	}
 }
 
-// NatsOpts allows setting Options from nats package directly
-func NatsOpts(opt func(*natsServer.Options)) Option {
-	return func(no *natsServer.Options, _ *stanServer.Options) {
-		opt(no)
-	}
-}
-
-// StanOpts allows setting Options from stan package directly
-func StanOpts(opt func(*stanServer.Options)) Option {
-	return func(_ *natsServer.Options, so *stanServer.Options) {
-		opt(so)
+// Port sets the host URL for the nats server
+func Logger(logger logger.Logger) Option {
+	return func(no *natsServer.Options, so *stanServer.Options) {
+		so.CustomLogger = logger
 	}
 }