shutdown gracefully on SIGINT/SIGTERM

Signed-off-by: Steve Kriss <steve@heptio.com>

pkg/cmd/server/server.go

@@ -21,10 +21,13 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
+	"os"
+	"os/signal"
 	"reflect"
 	"sort"
 	"strings"
 	"sync"
+	"syscall"
 	"time"
 
 	"github.com/heptio/ark/pkg/buildinfo"
@@ -237,6 +240,8 @@ func (s *server) run() error {
 
 	s.watchConfig(originalConfig)
 
+	s.handleShutdownSignals()
+
 	if err := s.initBackupService(config); err != nil {
 		return err
 	}
@@ -364,6 +369,17 @@ func (s *server) watchConfig(config *api.Config) {
 	})
 }
 
+func (s *server) handleShutdownSignals() {
+	sigs := make(chan os.Signal, 1)
+	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
+
+	go func() {
+		sig := <-sigs
+		s.logger.Infof("Received signal %s, gracefully shutting down", sig)
+		s.cancelFunc()
+	}()
+}
+
 func (s *server) initBackupService(config *api.Config) error {
 	s.logger.Info("Configuring cloud provider for backup service")
 	objectStore, err := getObjectStore(config.BackupStorageProvider.CloudProviderConfig, s.pluginManager)