feat: add function to retrieve object by path

Signed-off-by: Nikita Pivkin <[email protected]>

lib/cloud/metadata.rego

@@ -0,0 +1,18 @@
+# METADATA
+# custom:
+# library: true
+package lib.cloud.metadata
+
+import rego.v1
+
+# Returns the object found by the given path
+# if child object is not found, returns the last found object
+obj_by_path(obj, path) := res if {
+ occurrenses := {obj_path: child_object |
+ walk(obj, [obj_path, child_object])
+ child_object.__defsec_metadata
+ object.subset(path, obj_path)
+ }
+
+ res := occurrenses[max(object.keys(occurrenses))]
+} else := obj

lib/cloud/metadata_test.rego

@@ -0,0 +1,34 @@
+package lib.cloud.metadata_test
+
+import rego.v1
+
+import data.lib.cloud.metadata
+
+test_obj_by_path_happy if {
+ bar := with_meta({"value": 1})
+ obj := with_meta({"foo": with_meta({"bar": bar})})
+
+ metadata.obj_by_path(obj, ["foo", "bar"]) == bar
+}
+
+test_obj_by_path_when_target_not_found_then_return_last_found if {
+ foo := with_meta({"bar": with_meta({"value": 1})})
+ obj := with_meta({"foo": foo})
+
+ metadata.obj_by_path(obj, ["foo", "baz"]) == foo
+}
+
+test_obj_by_path_when_target_not_found_then_return_obj if {
+ foo := with_meta({"bar": with_meta({"value": 1})})
+ obj := with_meta({"foo": foo})
+
+ metadata.obj_by_path(obj, "baz") == obj
+}
+
+test_obj_by_path_skip_without_metadata if {
+ obj := with_meta({"foo": {"bar": with_meta({"value": 1})}})
+
+ metadata.obj_by_path(obj, ["foo", "baz"]) == obj
+}
+
+with_meta(obj) := object.union(obj, {"__defsec_metadata": {}})