Add support for staging and purging

cmds/updatemgr/update.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"path/filepath"
+
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	rootCmd.AddCommand(updateCmd)
+}
+
+var updateCmd = &cobra.Command{
+	Use:   "update",
+	Short: "Update scans the specified directory and registry the index and symlink structure",
+	Args:  cobra.ExactArgs(1),
+	RunE:  update,
+}
+
+func update(cmd *cobra.Command, args []string) error {
+	err := scanStorage()
+	if err != nil {
+		return err
+	}
+
+	// Export versions.
+	betaData, err := json.MarshalIndent(exportSelected(true), "", " ")
+	if err != nil {
+		return err
+	}
+	stableData, err := json.MarshalIndent(exportSelected(false), "", " ")
+	if err != nil {
+		return err
+	}
+
+	// Build destination paths.
+	betaIndexFilePath := filepath.Join(registry.StorageDir().Path, "beta.json")
+	stableIndexFilePath := filepath.Join(registry.StorageDir().Path, "stable.json")
+
+	// Print previews.
+	fmt.Printf("beta (%s):\n", betaIndexFilePath)
+	fmt.Println(string(betaData))
+	fmt.Printf("\nstable: (%s)\n", stableIndexFilePath)
+	fmt.Println(string(stableData))
+
+	// Ask for confirmation.
+	if !confirm("\nDo you want to write these new indexes (and update latest symlinks)?") {
+		fmt.Println("aborted...")
+		return nil
+	}
+
+	// Write indexes.
+	err = ioutil.WriteFile(betaIndexFilePath, betaData, 0o644) //nolint:gosec // 0644 is intended
+	if err != nil {
+		return err
+	}
+	fmt.Printf("written %s\n", betaIndexFilePath)
+
+	err = ioutil.WriteFile(stableIndexFilePath, stableData, 0o644) //nolint:gosec // 0644 is intended
+	if err != nil {
+		return err
+	}
+	fmt.Printf("written %s\n", stableIndexFilePath)
+
+	// Create symlinks to latest stable versions.
+	symlinksDir := registry.StorageDir().ChildDir("latest", 0o755)
+	err = registry.CreateSymlinks(symlinksDir)
+	if err != nil {
+		return err
+	}
+	fmt.Printf("updated stable symlinks in %s\n", symlinksDir.Path)
+
+	return nil
+}