feat(ext): determinism in exporting and declarative formats

cmd/flipt/export.go

@@ -19,6 +19,7 @@ type exportCommand struct {
 	token         string
 	namespaces    string // comma delimited list of namespaces
 	allNamespaces bool
+	sortByKey     bool
 }
 
 func newExportCommand() *cobra.Command {
@@ -72,6 +73,13 @@ func newExportCommand() *cobra.Command {
 		"export all namespaces. (mutually exclusive with --namespaces)",
 	)
 
+	cmd.Flags().BoolVar(
+		&export.sortByKey,
+		"sort-by-key",
+		false,
+		"sort exported resources by key",
+	)
+
 	cmd.Flags().StringVar(&providedConfigFile, "config", "", "path to config file")
 
 	cmd.MarkFlagsMutuallyExclusive("all-namespaces", "namespaces", "namespace")
@@ -139,5 +147,5 @@ func (c *exportCommand) run(cmd *cobra.Command, _ []string) error {
 }
 
 func (c *exportCommand) export(ctx context.Context, enc ext.Encoding, dst io.Writer, lister ext.Lister) error {
-	return ext.NewExporter(lister, c.namespaces, c.allNamespaces).Export(ctx, enc, dst)
+	return ext.NewExporter(lister, c.namespaces, c.allNamespaces, c.sortByKey).Export(ctx, enc, dst)
 }

internal/ext/exporter.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"sort"
 	"strings"
 
 	"github.com/blang/semver/v4"
@@ -44,16 +45,18 @@ type Exporter struct {
 	batchSize     int32
 	namespaceKeys []string
 	allNamespaces bool
+	sortByKey     bool
 }
 
-func NewExporter(store Lister, namespaces string, allNamespaces bool) *Exporter {
+func NewExporter(store Lister, namespaces string, allNamespaces, sortByKey bool) *Exporter {
 	ns := strings.Split(namespaces, ",")
 
 	return &Exporter{
 		store:         store,
 		batchSize:     defaultBatchSize,
 		namespaceKeys: ns,
 		allNamespaces: allNamespaces,
+		sortByKey:     sortByKey,
 	}
 }
 
@@ -316,6 +319,17 @@ func (e *Exporter) Export(ctx context.Context, encoding Encoding, w io.Writer) e
 			}
 		}
 
+		// sort flags and segments by key if sorting is enabled
+		if e.sortByKey {
+			sort.SliceStable(doc.Flags, func(i, j int) bool {
+				return doc.Flags[i].Key < doc.Flags[j].Key
+			})
+
+			sort.SliceStable(doc.Segments, func(i, j int) bool {
+				return doc.Segments[i].Key < doc.Segments[j].Key
+			})
+		}
+
 		if err := enc.Encode(doc); err != nil {
 			return fmt.Errorf("marshaling document: %w", err)
 		}