Allow simple interaction with record encoder

Mainly used for record importer; might rework/remove at a later
point.

pkg/envoy/store/compose_record.go

@@ -129,6 +129,24 @@ func (n *composeRecordState) Encode(ctx context.Context, s store.Storer, state *
 	im := n.res.IDMap
 
 	return n.res.Walker(func(r *resource.ComposeRecordRaw) error {
+		// Simple wrapper to do some post-processing steps
+		dfr := func(err error) error {
+			if n.cfg.Defer != nil {
+				n.cfg.Defer()
+			}
+
+			if err != nil {
+				if n.cfg.DeferNok != nil {
+					return n.cfg.DeferNok(err)
+				}
+				return err
+			} else if n.cfg.DeferOk != nil {
+				n.cfg.DeferOk()
+			}
+
+			return nil
+		}
+
 		rec := &types.Record{
 			ID:          im[r.ID],
 			NamespaceID: nsID,
@@ -170,24 +188,17 @@ func (n *composeRecordState) Encode(ctx context.Context, s store.Storer, state *
 		rec.Values = rvSanitizer.Run(mod, rvs)
 		rve := rvValidator.Run(ctx, s, mod, rec)
 		if !rve.IsValid() {
-			return rve
+			return dfr(rve)
 		}
 
 		// Create a new record
 		if !exists {
 			err = store.CreateComposeRecord(ctx, s, mod, rec)
-			if err != nil {
-				return err
-			}
-			return nil
+			return dfr(err)
 		}
 
 		// Update existing
 		err = store.UpdateComposeRecord(ctx, s, mod, rec)
-		if err != nil {
-			return err
-		}
-
-		return nil
+		return dfr(err)
 	})
 }

pkg/envoy/store/encoder.go

@@ -38,6 +38,14 @@ type (
 	// EncoderConfig allows us to configure the resource encoding process
 	EncoderConfig struct {
 		OnExisting mergeAlg
+		// Defer is called after the resource is encoded, regardles of the result
+		Defer func()
+		// DeferOk is called after the resource is encoded, only when successful
+		DeferOk func()
+		// DeferNok is called after the resource is encoded, only when failed
+		// If you return an error, the encoding will terminate.
+		// If you return nil (ignore the error), the encoding will continue.
+		DeferNok func(error) error
 	}
 
 	// resourceState allows each conforming struct to be initialized and encoded