BUG/MINOR: Return the correct error code when adding duplicates into a map file

Author: oliwer

e2e/tests/acl_files/acl_file_entries.bats

@@ -57,6 +57,10 @@ load 'utils/_helpers'
   resource_post "$_RUNTIME_ACL_BASE_PATH/$PARENT_NAME/entries" "data/post.json"
   assert_equal "$SC" 201
   assert_equal "$(get_json_path "${BODY}" " .value" )" "/js"
+
+  # Adding the same entry twice should return a 409 error.
+  resource_post "$_RUNTIME_ACL_BASE_PATH/$PARENT_NAME/entries" "data/post.json"
+  assert_equal "$SC" 409
 }
 
 @test "acl_runtime: Delete an ACL file entry by its ID" {

misc/misc.go

@@ -102,6 +102,8 @@ func HandleError(err error) *models.Error {
 		code := ErrHTTPInternalServerError
 		if errors.Is(t, client_errors.ErrNotFound) {
 			code = ErrHTTPNotFound
+		} else if errors.Is(t, client_errors.ErrAlreadyExists) {
+			code = ErrHTTPConflict
 		}
 		return &models.Error{Code: &code, Message: &msg}
 	}