Add a keyspace configuration in the vschema for foreign key mode (#…

…13553)

Signed-off-by: Manan Gupta <[email protected]>

go/vt/vtgate/vindexes/vschema.go

@@ -175,19 +175,21 @@ func (col *Column) MarshalJSON() ([]byte, error) {
 
 // KeyspaceSchema contains the schema(table) for a keyspace.
 type KeyspaceSchema struct {
-	Keyspace *Keyspace
-	Tables   map[string]*Table
-	Vindexes map[string]Vindex
-	Views    map[string]sqlparser.SelectStatement
-	Error    error
+	Keyspace       *Keyspace
+	ForeignKeyMode vschemapb.Keyspace_ForeignKeyMode
+	Tables         map[string]*Table
+	Vindexes       map[string]Vindex
+	Views          map[string]sqlparser.SelectStatement
+	Error          error
 }
 
 type ksJSON struct {
-	Sharded  bool              `json:"sharded,omitempty"`
-	Tables   map[string]*Table `json:"tables,omitempty"`
-	Vindexes map[string]Vindex `json:"vindexes,omitempty"`
-	Views    map[string]string `json:"views,omitempty"`
-	Error    string            `json:"error,omitempty"`
+	Sharded        bool              `json:"sharded,omitempty"`
+	ForeignKeyMode string            `json:"foreignKeyMode,omitempty"`
+	Tables         map[string]*Table `json:"tables,omitempty"`
+	Vindexes       map[string]Vindex `json:"vindexes,omitempty"`
+	Views          map[string]string `json:"views,omitempty"`
+	Error          string            `json:"error,omitempty"`
 }
 
 // findTable looks for the table with the requested tablename in the keyspace.
@@ -216,9 +218,10 @@ func (ks *KeyspaceSchema) findTable(
 // MarshalJSON returns a JSON representation of KeyspaceSchema.
 func (ks *KeyspaceSchema) MarshalJSON() ([]byte, error) {
 	ksJ := ksJSON{
-		Sharded:  ks.Keyspace.Sharded,
-		Tables:   ks.Tables,
-		Vindexes: ks.Vindexes,
+		Sharded:        ks.Keyspace.Sharded,
+		Tables:         ks.Tables,
+		ForeignKeyMode: ks.ForeignKeyMode.String(),
+		Vindexes:       ks.Vindexes,
 	}
 	if ks.Error != nil {
 		ksJ.Error = ks.Error.Error()
@@ -304,14 +307,23 @@ func buildKeyspaces(source *vschemapb.SrvVSchema, vschema *VSchema) {
 				Name:    ksname,
 				Sharded: ks.Sharded,
 			},
-			Tables:   make(map[string]*Table),
-			Vindexes: make(map[string]Vindex),
+			ForeignKeyMode: replaceDefaultForeignKeyMode(ks.ForeignKeyMode),
+			Tables:         make(map[string]*Table),
+			Vindexes:       make(map[string]Vindex),
 		}
 		vschema.Keyspaces[ksname] = ksvschema
 		ksvschema.Error = buildTables(ks, vschema, ksvschema)
 	}
 }
 
+// replaceDefaultForeignKeyMode replaces the default value of the foreign key mode enum with the default we want to keep.
+func replaceDefaultForeignKeyMode(fkMode vschemapb.Keyspace_ForeignKeyMode) vschemapb.Keyspace_ForeignKeyMode {
+	if fkMode == vschemapb.Keyspace_FK_DEFAULT {
+		return vschemapb.Keyspace_FK_UNMANAGED
+	}
+	return fkMode
+}
+
 func (vschema *VSchema) AddView(ksname string, viewName, query string) error {
 	ks, ok := vschema.Keyspaces[ksname]
 	if !ok {