check uplink setup (#339)

* check uplink setup

* code review comments changes

cmd/uplink/cmd/ls.go

@@ -78,7 +78,7 @@ func list(cmd *cobra.Command, args []string) error {
 	}
 
 	if noBuckets {
-		return fmt.Errorf("No buckets")
+		fmt.Println("No buckets")
 	}
 
 	return nil

cmd/uplink/cmd/run.go

@@ -4,6 +4,7 @@
 package cmd
 
 import (
+	"errors"
 	"fmt"
 	"net"
 
@@ -39,5 +40,16 @@ func cmdRun(cmd *cobra.Command, args []string) (err error) {
 	fmt.Printf("Access key: %s\n", cfg.AccessKey)
 	fmt.Printf("Secret key: %s\n", cfg.SecretKey)
 
+	ctx := process.Ctx(cmd)
+	bs, err := cfg.BucketStore(ctx)
+	if err != nil {
+		return err
+	}
+
+	_, _, err = bs.List(ctx, "", "", 0)
+	if err != nil {
+		return errors.New("uplink setup error")
+	}
+
 	return cfg.Run(process.Ctx(cmd))
 }

pkg/storage/buckets/store.go

@@ -122,6 +122,9 @@ func (b *BucketStore) List(ctx context.Context, startAfter, endBefore string, li
 	items []ListItem, more bool, err error) {
 	defer mon.Task()(&ctx)(&err)
 	objItems, more, err := b.o.List(ctx, nil, paths.New(startAfter), paths.New(endBefore), false, limit, meta.Modified)
+	if err != nil {
+		return items, more, err
+	}
 	items = make([]ListItem, 0, len(objItems))
 	for _, itm := range objItems {
 		if itm.IsPrefix {