start server in goroutine and shutdown gracefully

cmd/manager/main.go

@@ -19,6 +19,7 @@ package main
 import (
 	"flag"
 	"fmt"
+	"net/http"
 	"os"
 
 	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
@@ -36,7 +37,7 @@ import (
 
 	"github.com/operator-framework/catalogd/internal/source"
 	"github.com/operator-framework/catalogd/internal/version"
-	catalogserver "github.com/operator-framework/catalogd/pkg/catalogserver"
+	"github.com/operator-framework/catalogd/pkg/catalogserver"
 	corecontrollers "github.com/operator-framework/catalogd/pkg/controllers/core"
 	"github.com/operator-framework/catalogd/pkg/features"
 	"github.com/operator-framework/catalogd/pkg/profile"
@@ -68,7 +69,7 @@ func main() {
 		catalogdVersion      bool
 		systemNamespace      string
 		storageDir           string
-		serverPort           string
+		catalogServerAddr    string
 	)
 	flag.StringVar(&metricsAddr, "metrics-bind-address", ":8080", "The address the metric endpoint binds to.")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
@@ -78,8 +79,8 @@ func main() {
 	// TODO: should we move the unpacker to some common place? Or... hear me out... should catalogd just be a rukpak provisioner?
 	flag.StringVar(&unpackImage, "unpack-image", "quay.io/operator-framework/rukpak:v0.12.0", "The unpack image to use when unpacking catalog images")
 	flag.StringVar(&systemNamespace, "system-namespace", "", "The namespace catalogd uses for internal state, configuration, and workloads")
-	flag.StringVar(&storageDir, "catalogs-storage-dir", "/var/cache", "The directory in the filesystem where unpacked catalog content will be stored and served from")
-	flag.StringVar(&serverPort, "catalogs-server-port", ":8083", "The port where the unpacked catalogs' content will be accessible")
+	flag.StringVar(&storageDir, "catalogs-storage-dir", "/var/cache/catalogs", "The directory in the filesystem where unpacked catalog content will be stored and served from")
+	flag.StringVar(&catalogServerAddr, "catalogs-server-addr", "127.0.0.1:8083", "The port where the unpacked catalogs' content will be accessible")
 	flag.BoolVar(&profiling, "profiling", false, "enable profiling endpoints to allow for using pprof")
 	flag.BoolVar(&catalogdVersion, "version", false, "print the catalogd version and exit")
 	opts := zap.Options{
@@ -122,16 +123,22 @@ func main() {
 		os.Exit(1)
 	}
 
-	catalogServer := catalogserver.NewServer(storageDir, serverPort)
+	serverMux := &http.ServeMux{}
+	catalogServer := catalogserver.New(storageDir, catalogServerAddr, serverMux)
 	if err := mgr.Add(catalogServer); err != nil {
 		setupLog.Error(err, "unable to start catalog server")
 		os.Exit(1)
 	}
 
+	if _, err := os.Stat(storageDir); os.IsNotExist(err) {
+		if err := os.MkdirAll(storageDir, 0700); err != nil {
+			setupLog.Error(err, "unable to create storage directory for catalogs")
+		}
+	}
 	if err = (&corecontrollers.CatalogReconciler{
 		Client:   mgr.GetClient(),
 		Unpacker: unpacker,
-		Storage:  storage.NewStorage(storageDir, catalogServer.Mux),
+		Storage:  storage.NewStorage(storageDir, serverMux),
 	}).SetupWithManager(mgr); err != nil {
 		setupLog.Error(err, "unable to create controller", "controller", "Catalog")
 		os.Exit(1)

pkg/catalogserver/server.go

@@ -9,26 +9,27 @@ import (
 	"time"
 )
 
-// Server is a manager.Runnable Server, that serves the FBC
-// content of the extension catalogs added to the cluster
-type Server struct {
+// Instance is a manager.Runnable catalog server instance,
+// that serves the FBC content of the extension catalogs
+// added to the cluster
+type Instance struct {
 	Dir  string
 	Port string
 	Mux  *http.ServeMux
 }
 
-// NewServer takes directory and port number, and returns
-// a Server that serves the FBC content stored in the
-// directory on the given port number.
-func NewServer(dir, port string) Server {
-	return Server{
+// New returns an Instance of a catalog server that serves
+// the FBC content stored in the given directory on the given
+// http address.
+func New(dir, port string, mux *http.ServeMux) Instance {
+	return Instance{
 		Dir:  dir,
 		Port: port,
-		Mux:  &http.ServeMux{},
+		Mux:  mux,
 	}
 }
 
-func (s Server) Start(_ context.Context) error {
+func (s Instance) Start(ctx context.Context) error {
 	s.Mux.HandleFunc("/catalogs", func(w http.ResponseWriter, r *http.Request) {
 		files, err := os.ReadDir(s.Dir)
 		if err != nil {
@@ -46,5 +47,17 @@ func (s Server) Start(_ context.Context) error {
 		Addr:              s.Port,
 		ReadHeaderTimeout: 3 * time.Second,
 	}
-	return server.ListenAndServe()
+	e := make(chan error)
+	go func(server *http.Server, e chan error) {
+		err := server.ListenAndServe()
+		e <- err
+		close(e)
+	}(server, e)
+	err := <-e
+	if err != nil {
+		return err
+	}
+
+	<-ctx.Done()
+	return server.Shutdown(context.TODO())
 }