Refactor component/extras into snapshotting

internal/component/snapshots/extras_bookkeeping.go

@@ -0,0 +1,29 @@
+package snapshots
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/component"
+	"github.com/FAU-CDI/wisski-distillery/internal/models"
+)
+
+type Bookkeeping struct {
+	component.ComponentBase
+}
+
+func (Bookkeeping) Name() string { return "bookkeeping" }
+
+// SnapshotNeedsRunning returns if this Snapshotable requires a running instance.
+func (Bookkeeping) SnapshotNeedsRunning() bool { return false }
+
+// SnapshotName returns a new name to be used as an argument for path.
+func (Bookkeeping) SnapshotName() string { return "bookkeeping.txt" }
+
+// Snapshot creates a snapshot of this instance
+func (*Bookkeeping) Snapshot(wisski models.Instance, context component.StagingContext) error {
+	return context.AddFile(".", func(file io.Writer) error {
+		_, err := fmt.Fprintf(file, "%#v\n", wisski)
+		return err
+	})
+}