Add support for staging and purging

cmds/updatemgr/purge.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/spf13/cobra"
+
+	"github.com/safing/portbase/log"
+	"github.com/safing/portbase/updater"
+)
+
+func init() {
+	rootCmd.AddCommand(purgeCmd)
+}
+
+var purgeCmd = &cobra.Command{
+	Use:   "purge",
+	Short: "Remove old resource versions that are superseded by at least three versions",
+	Args:  cobra.ExactArgs(1),
+	RunE:  purge,
+}
+
+func purge(cmd *cobra.Command, args []string) error {
+	log.SetLogLevel(log.TraceLevel)
+	err := log.Start()
+	if err != nil {
+		fmt.Printf("failed to start logging: %s\n", err)
+	}
+	defer log.Shutdown()
+
+	registry.AddIndex(updater.Index{
+		Path:   "stable.json",
+		Stable: true,
+		Beta:   false,
+	})
+
+	registry.AddIndex(updater.Index{
+		Path:   "beta.json",
+		Stable: false,
+		Beta:   true,
+	})
+
+	err = registry.LoadIndexes(context.TODO())
+	if err != nil {
+		return err
+	}
+
+	err = scanStorage()
+	if err != nil {
+		return err
+	}
+
+	registry.SelectVersions()
+	registry.Purge(3)
+
+	return nil
+}