Add certwatcher for TLS cert and key from controller-runtime

- Add error for missing either tls-key or tls-cert arguments.
- Move server creation and configuration to serverutil

Signed-off-by: Tayler Geiger <tayler@redhat.com>

cmd/manager/main.go

@@ -17,11 +17,8 @@ limitations under the License.
 package main
 
 import (
-	"crypto/tls"
 	"flag"
 	"fmt"
-	"net"
-	"net/http"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -41,8 +38,8 @@ import (
 
 	"github.com/operator-framework/catalogd/api/core/v1alpha1"
 	"github.com/operator-framework/catalogd/internal/garbagecollection"
+	"github.com/operator-framework/catalogd/internal/serverutil"
 	"github.com/operator-framework/catalogd/internal/source"
-	"github.com/operator-framework/catalogd/internal/third_party/server"
 	"github.com/operator-framework/catalogd/internal/version"
 	corecontrollers "github.com/operator-framework/catalogd/pkg/controllers/core"
 	"github.com/operator-framework/catalogd/pkg/features"
@@ -78,7 +75,6 @@ func main() {
 		gcInterval           time.Duration
 		certFile             string
 		keyFile              string
-		listener             net.Listener
 	)
 	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.")
@@ -92,8 +88,8 @@ func main() {
 	flag.StringVar(&cacheDir, "cache-dir", "/var/cache/", "The directory in the filesystem that catalogd will use for file based caching")
 	flag.BoolVar(&catalogdVersion, "version", false, "print the catalogd version and exit")
 	flag.DurationVar(&gcInterval, "gc-interval", 12*time.Hour, "interval in which garbage collection should be run against the catalog content cache")
-	flag.StringVar(&certFile, "tls-cert", "", "The certificate file used for serving catalog contents over HTTPS")
-	flag.StringVar(&keyFile, "tls-key", "", "The key file used for serving catalog contents over HTTPS")
+	flag.StringVar(&certFile, "tls-cert", "", "The certificate file used for serving catalog contents over HTTPS. Requires tls-key.")
+	flag.StringVar(&keyFile, "tls-key", "", "The key file used for serving catalog contents over HTTPS. Requires tls-cert.")
 	opts := zap.Options{
 		Development: true,
 	}
@@ -110,6 +106,17 @@ func main() {
 	}
 
 	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))
+
+	if (certFile != "" && keyFile == "") || (certFile == "" && keyFile != "") {
+		setupLog.Error(nil, "unable to configure TLS certificates: tls-cert and tls-key flags must be used together")
+		os.Exit(1)
+	}
+
+	protocol := "http"
+	if certFile != "" && keyFile != "" {
+		protocol = "https"
+	}
+
 	cfg := ctrl.GetConfigOrDie()
 	mgr, err := ctrl.NewManager(cfg, ctrl.Options{
 		Scheme: scheme,
@@ -150,56 +157,26 @@ func main() {
 		os.Exit(1)
 	}
 
-	if certFile != "" && keyFile != "" {
-		cert, err := tls.LoadX509KeyPair(certFile, keyFile)
-		if err != nil {
-			setupLog.Error(err, "unable to load certificate key pair")
-			os.Exit(1)
-		}
-		config := &tls.Config{
-			Certificates: []tls.Certificate{cert},
-			MinVersion:   tls.VersionTLS13,
-		}
-		listener, err = tls.Listen("tcp", catalogServerAddr, config)
-		if err != nil {
-			setupLog.Error(err, "unable to create HTTPS server listener")
-			os.Exit(1)
-		}
-		externalAddr = "https://" + externalAddr
-	} else {
-		listener, err = net.Listen("tcp", catalogServerAddr)
-		if err != nil {
-			setupLog.Error(err, "unable to create HTTP server listener")
-			os.Exit(1)
-		}
-		externalAddr = "http://" + externalAddr
-	}
-
-	baseStorageURL, err := url.Parse(fmt.Sprintf("%s/catalogs/", externalAddr))
+	baseStorageURL, err := url.Parse(fmt.Sprintf("%s://%s/catalogs/", protocol, externalAddr))
 	if err != nil {
 		setupLog.Error(err, "unable to create base storage URL")
 		os.Exit(1)
 	}
 
 	localStorage = storage.LocalDir{RootDir: storeDir, BaseURL: baseStorageURL}
-	shutdownTimeout := 30 * time.Second
-
-	catalogServer := server.Server{
-		Kind: "catalogs",
-		Server: &http.Server{
-			Addr:        catalogServerAddr,
-			Handler:     catalogdmetrics.AddMetricsToHandler(localStorage.StorageServerHandler()),
-			ReadTimeout: 5 * time.Second,
-			// TODO: Revert this to 10 seconds if/when the API
-			// evolves to have significantly smaller responses
-			WriteTimeout: 5 * time.Minute,
-		},
-		ShutdownTimeout: &shutdownTimeout,
-		Listener:        listener,
+
+	catalogServerConfig := serverutil.CatalogServerConfig{
+		StoreDir:     storeDir,
+		ExternalAddr: externalAddr,
+		CatalogAddr:  catalogServerAddr,
+		CertFile:     certFile,
+		KeyFile:      keyFile,
+		LocalStorage: localStorage,
 	}
 
-	if err := mgr.Add(&catalogServer); err != nil {
-		setupLog.Error(err, "unable to start catalog server")
+	err = serverutil.AddCatalogServerToManager(mgr, catalogServerConfig)
+	if err != nil {
+		setupLog.Error(err, "unable to add catalog server to manager")
 		os.Exit(1)
 	}
 
@@ -236,7 +213,7 @@ func main() {
 		Interval:       gcInterval,
 	}
 	if err := mgr.Add(gc); err != nil {
-		setupLog.Error(err, "problem adding garbage collector to manager")
+		setupLog.Error(err, "unable to add garbage collector to manager")
 		os.Exit(1)
 	}
 

internal/serverutil/serverutil.go

@@ -0,0 +1,69 @@
+package serverutil
+
+import (
+	"crypto/tls"
+	"net"
+	"net/http"
+	"time"
+
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/certwatcher"
+
+	"github.com/operator-framework/catalogd/internal/third_party/server"
+	catalogdmetrics "github.com/operator-framework/catalogd/pkg/metrics"
+	"github.com/operator-framework/catalogd/pkg/storage"
+)
+
+type CatalogServerConfig struct {
+	ExternalAddr string
+	CatalogAddr  string
+	CertFile     string
+	KeyFile      string
+	LocalStorage storage.Instance
+}
+
+func AddCatalogServerToManager(mgr ctrl.Manager, cfg CatalogServerConfig) error {
+	listener, err := net.Listen("tcp", cfg.CatalogAddr)
+	if err != nil {
+		return err
+	}
+
+	if cfg.CertFile != "" && cfg.KeyFile != "" {
+		tlsFileWatcher, err := certwatcher.New(cfg.CertFile, cfg.KeyFile)
+		if err != nil {
+			return err
+		}
+		config := &tls.Config{
+			GetCertificate: tlsFileWatcher.GetCertificate,
+			MinVersion:     tls.VersionTLS12,
+		}
+		err = mgr.Add(tlsFileWatcher)
+		if err != nil {
+			return err
+		}
+		listener = tls.NewListener(listener, config)
+	}
+
+	shutdownTimeout := 30 * time.Second
+
+	catalogServer := server.Server{
+		Kind: "catalogs",
+		Server: &http.Server{
+			Addr:        cfg.CatalogAddr,
+			Handler:     catalogdmetrics.AddMetricsToHandler(cfg.LocalStorage.StorageServerHandler()),
+			ReadTimeout: 5 * time.Second,
+			// TODO: Revert this to 10 seconds if/when the API
+			// evolves to have significantly smaller responses
+			WriteTimeout: 5 * time.Minute,
+		},
+		ShutdownTimeout: &shutdownTimeout,
+		Listener:        listener,
+	}
+
+	err = mgr.Add(&catalogServer)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}