add new command to show layers that are needed in the repo

Author: siscia

daemon/cmd/list_needed_layers.go

@@ -0,0 +1,32 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"github.com/cvmfs/docker-graphdriver/daemon/lib"
+)
+
+func init() {
+	listNeededLayers.Flags().BoolVarP(&machineFriendly, "machine-friendly", "z", false, "produce machine friendly output, one line of csv")
+	rootCmd.AddCommand(listNeededLayers)
+}
+
+var listNeededLayers = &cobra.Command{
+	Use:     "list-needed-layers",
+	Short:   "Show all the layers that are needed",
+	Aliases: []string{"list-needed-layer", "ls-layer", "ls-layers", "layer-ls", "layers-ls", "list-layers", "list-layer"},
+	Run: func(cmd *cobra.Command, args []string) {
+		layers, err := lib.GetAllNeededLayers()
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+		for _, layer := range layers {
+			fmt.Println(layer)
+		}
+		os.Exit(0)
+	},
+}

daemon/lib/sql.go

@@ -749,9 +749,9 @@ func GetAllNeededImages() ([]string, error) {
 	return images, nil
 }
 
-var getAllNeededLayers = fmt.Sprint(`
+var getAllNeededLayers = fmt.Sprintf(`
 SELECT DISTINCT( 
-	'/cvmfs/' || wish.cvmfs_repo || '%s' || substr(json_extract(layers.value, '$.Digest'), 8)
+	'/cvmfs/' || wish.cvmfs_repo || '/'|| '%s' || '/' || substr(json_extract(layers.value, '$.Digest'), 8)
 	) 
 FROM 
 converted, wish, json_each(converted.manifest, '$.Layers') as layers WHERE