Extend hidden_fields to allow more complicated field definitions (#872)

SUMMARY
This allows us to ignore e.g. the last-applied-configuration annotation by specifying
metadata.annotations[kubectl.kubernetes.io/last-applied-configuration]
ISSUE TYPE

Feature Pull Request

COMPONENT NAME
hidden_fields
This replaces #643 as I no longer have permissions to push to branches in this repo

Reviewed-by: Bikouo Aubin
Reviewed-by: Helen Bailey <hebailey@redhat.com>
Reviewed-by: GomathiselviS <gomathiselvi@gmail.com>
Reviewed-by: Alina Buzachis

plugins/module_utils/k8s/service.py

@@ -4,7 +4,7 @@
 import copy
 from json import loads
 from re import compile
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any, Dict, List, Optional, Tuple, Union
 
 from ansible.module_utils.common.dict_transformations import dict_merge
 from ansible_collections.kubernetes.core.plugins.module_utils.hashes import (
@@ -501,47 +501,107 @@ def diff_objects(
     result["before"] = diff[0]
     result["after"] = diff[1]
 
-    if list(result["after"].keys()) != ["metadata"] or list(
+    if list(result["after"].keys()) == ["metadata"] and list(
         result["before"].keys()
-    ) != ["metadata"]:
-        return False, result
+    ) == ["metadata"]:
+        # If only metadata.generation and metadata.resourceVersion changed, ignore it
+        ignored_keys = set(["generation", "resourceVersion"])
 
-    # If only metadata.generation and metadata.resourceVersion changed, ignore it
-    ignored_keys = set(["generation", "resourceVersion"])
-
-    if not set(result["after"]["metadata"].keys()).issubset(ignored_keys):
-        return False, result
-    if not set(result["before"]["metadata"].keys()).issubset(ignored_keys):
-        return False, result
+        if set(result["after"]["metadata"].keys()).issubset(ignored_keys) and set(
+            result["before"]["metadata"].keys()
+        ).issubset(ignored_keys):
+            return True, result
 
     result["before"] = hide_fields(result["before"], hidden_fields)
     result["after"] = hide_fields(result["after"], hidden_fields)
 
-    return True, result
+    return False, result
 
 
-def hide_fields(definition: dict, hidden_fields: Optional[list]) -> dict:
-    if not hidden_fields:
-        return definition
-    result = copy.deepcopy(definition)
-    for hidden_field in hidden_fields:
-        result = hide_field(result, hidden_field)
+def hide_field_tree(hidden_field: str) -> List[str]:
+    result = []
+    key, rest = hide_field_split2(hidden_field)
+    result.append(key)
+    while rest:
+        key, rest = hide_field_split2(rest)
+        result.append(key)
+
     return result
 
 
-# hide_field is not hugely sophisticated and designed to cope
-# with e.g. status or metadata.managedFields rather than e.g.
-# spec.template.spec.containers[0].env[3].value
-def hide_field(definition: dict, hidden_field: str) -> dict:
-    split = hidden_field.split(".", 1)
-    if split[0] in definition:
-        if len(split) == 2:
-            definition[split[0]] = hide_field(definition[split[0]], split[1])
-        else:
-            del definition[split[0]]
+def build_hidden_field_tree(hidden_fields: List[str]) -> Dict[str, Any]:
+    """Group hidden field targeting the same json key
+    Example:
+        Input: ['env[3]', 'env[0]']
+        Output: {'env': [0, 3]}
+    """
+    output = {}
+    for hidden_field in hidden_fields:
+        current = output
+        tree = hide_field_tree(hidden_field)
+        for idx, key in enumerate(tree):
+            if current.get(key, "") is None:
+                break
+            if idx == (len(tree) - 1):
+                current[key] = None
+            elif key not in current:
+                current[key] = {}
+            current = current[key]
+    return output
+
+
+# hide_field should be able to cope with simple or more complicated
+# field definitions
+# e.g. status or metadata.managedFields or
+# spec.template.spec.containers[0].env[3].value or
+# metadata.annotations[kubectl.kubernetes.io/last-applied-configuration]
+def hide_field(
+    definition: Union[Dict[str, Any], List[Any]], hidden_field: Dict[str, Any]
+) -> Dict[str, Any]:
+    def dict_contains_key(obj: Dict[str, Any], key: str) -> bool:
+        return key in obj
+
+    def list_contains_key(obj: List[Any], key: str) -> bool:
+        return int(key) < len(obj)
+
+    hidden_keys = list(hidden_field.keys())
+    field_contains_key = dict_contains_key
+    field_get_key = str
+    if isinstance(definition, list):
+        # Sort with reverse=true so that when we delete an item from the list, the order is not changed
+        hidden_keys = sorted(
+            [k for k in hidden_field.keys() if k.isdecimal()], reverse=True
+        )
+        field_contains_key = list_contains_key
+        field_get_key = int
+
+    for key in hidden_keys:
+        if field_contains_key(definition, key):
+            value = hidden_field.get(key)
+            convert_key = field_get_key(key)
+            if value is None:
+                del definition[convert_key]
+            else:
+                definition[convert_key] = hide_field(definition[convert_key], value)
+                if (
+                    definition[convert_key] == dict()
+                    or definition[convert_key] == list()
+                ):
+                    del definition[convert_key]
+
     return definition
 
 
+def hide_fields(
+    definition: Dict[str, Any], hidden_fields: Optional[List[str]]
+) -> Dict[str, Any]:
+    if not hidden_fields:
+        return definition
+    result = copy.deepcopy(definition)
+    hidden_field_tree = build_hidden_field_tree(hidden_fields)
+    return hide_field(result, hidden_field_tree)
+
+
 def decode_response(resp) -> Tuple[Dict, List[str]]:
     """
     This function decodes unserialized responses from the Kubernetes python
@@ -620,3 +680,35 @@ def parse_quoted_string(quoted_string: str) -> Tuple[str, str]:
         raise ValueError("invalid quoted string: missing closing quote")
 
     return "".join(result), remainder
+
+
+# hide_field_split2 returns the first key in hidden_field and the rest of the hidden_field
+# We expect the first key to either be in brackets, to be terminated by the start of a left
+# bracket, or to be terminated by a dot.
+
+# examples would be:
+# field.another.next -> (field, another.next)
+# field[key].value -> (field, [key].value)
+# [key].value -> (key, value)
+# [one][two] -> (one, [two])
+
+
+def hide_field_split2(hidden_field: str) -> Tuple[str, str]:
+    lbracket = hidden_field.find("[")
+    rbracket = hidden_field.find("]")
+    dot = hidden_field.find(".")
+
+    if lbracket == 0:
+        # skip past right bracket and any following dot
+        rest = hidden_field[rbracket + 1 :]  # noqa: E203
+        if rest and rest[0] == ".":
+            rest = rest[1:]
+        return (hidden_field[lbracket + 1 : rbracket], rest)  # noqa: E203
+
+    if lbracket != -1 and (dot == -1 or lbracket < dot):
+        return (hidden_field[:lbracket], hidden_field[lbracket:])
+
+    split = hidden_field.split(".", 1)
+    if len(split) == 1:
+        return split[0], ""
+    return split

plugins/modules/k8s.py

@@ -188,7 +188,8 @@ options:
     description:
       - Hide fields matching this option in the result
       - An example might be C(hidden_fields=[metadata.managedFields])
-      - Only field definitions that don't reference list items are supported (so V(spec.containers[0]) would not work)
+        or V(hidden_fields=[spec.containers[0].env[3].value])
+        or V(hidden_fields=[metadata.annotations[kubectl.kubernetes.io/last-applied-configuration]])
     type: list
     elements: str
     version_added: 3.0.0

plugins/modules/k8s_info.py

@@ -48,7 +48,8 @@ options:
     description:
       - Hide fields matching any of the field definitions in the result
       - An example might be C(hidden_fields=[metadata.managedFields])
-      - Only field definitions that don't reference list items are supported (so V(spec.containers[0]) would not work)
+        or V(hidden_fields=[spec.containers[0].env[3].value])
+        or V(hidden_fields=[metadata.annotations[kubectl.kubernetes.io/last-applied-configuration]])
     type: list
     elements: str
     version_added: 3.0.0