k8s: Display warnings to users (#701)

k8s: Display warnings to users

SUMMARY
This changes K8sService and the k8s module so warnings returned by the K8S API are displayed to the user.
Fixes kubevirt/kubevirt.core#30
Fixes kubevirt/kubevirt.core#31
ISSUE TYPE


Feature Pull Request

COMPONENT NAME


k8s module
K8sService

ADDITIONAL INFORMATION



Before:
TASK [Create VM] **********************************************************************************************************************************************
ok: [localhost]

After:
TASK [Create VM] **********************************************************************************************************************************************
[WARNING]: unknown field "spec.template.spec.disk"
[WARNING]: unknown field "spec.template.spec.domain.bogus"
ok: [localhost]

Reviewed-by: Adam Miller <admiller@redhat.com>
Reviewed-by: Mike Graves <mgraves@redhat.com>
Reviewed-by: Felix Matouschek <felix@matouschek.org>

plugins/module_utils/apply.py

@@ -149,6 +149,7 @@ def k8s_apply(resource, definition, **kwargs):
             force_conflicts=kwargs.get("force_conflicts"),
             field_manager=kwargs.get("field_manager"),
             dry_run=kwargs.get("dry_run"),
+            serialize=kwargs.get("serialize"),
         )
     if not existing:
         return resource.create(
@@ -158,6 +159,7 @@ def k8s_apply(resource, definition, **kwargs):
         return resource.get(
             name=definition["metadata"]["name"],
             namespace=definition["metadata"].get("namespace"),
+            **kwargs
         )
     return resource.patch(
         body=desired,

plugins/module_utils/k8s/runner.py

@@ -139,6 +139,7 @@ def perform_action(svc, definition: Dict, params: Dict) -> Dict:
 
     result = {"changed": False, "result": {}}
     instance = {}
+    warnings = []
 
     resource = svc.find_resource(kind, api_version, fail=True)
     definition["kind"] = resource.kind
@@ -172,7 +173,7 @@ def perform_action(svc, definition: Dict, params: Dict) -> Dict:
                 return result
 
         if params.get("apply"):
-            instance = svc.apply(resource, definition, existing)
+            instance, warnings = svc.apply(resource, definition, existing)
             result["method"] = "apply"
         elif not existing:
             if state == "patched":
@@ -183,16 +184,19 @@ def perform_action(svc, definition: Dict, params: Dict) -> Dict:
                     )
                 )
                 return result
-            instance = svc.create(resource, definition)
+            instance, warnings = svc.create(resource, definition)
             result["method"] = "create"
             result["changed"] = True
         elif params.get("force", False):
-            instance = svc.replace(resource, definition, existing)
+            instance, warnings = svc.replace(resource, definition, existing)
             result["method"] = "replace"
         else:
-            instance = svc.update(resource, definition, existing)
+            instance, warnings = svc.update(resource, definition, existing)
             result["method"] = "update"
 
+    if warnings:
+        result["warnings"] = warnings
+
     # If needed, wait and/or create diff
     success = True
 

plugins/module_utils/k8s/service.py

@@ -2,6 +2,8 @@
 # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
 
 import copy
+from json import loads
+from re import compile
 from typing import Any, Dict, List, Optional, Tuple
 
 from ansible.module_utils.common.dict_transformations import dict_merge
@@ -142,7 +144,7 @@ class K8sService:
         name: str,
         namespace: str,
         merge_type: str = None,
-    ) -> Dict:
+    ) -> Tuple[Dict, List[str]]:
         if merge_type == "json":
             self.module.deprecate(
                 msg="json as a merge_type value is deprecated. Please use the k8s_json_patch module instead.",
@@ -150,10 +152,10 @@ class K8sService:
                 collection_name="kubernetes.core",
             )
         try:
-            params = dict(name=name, namespace=namespace)
+            params = dict(name=name, namespace=namespace, serialize=False)
             if merge_type:
                 params["content_type"] = "application/{0}-patch+json".format(merge_type)
-            return self.client.patch(resource, definition, **params).to_dict()
+            return decode_response(self.client.patch(resource, definition, **params))
         except Exception as e:
             reason = e.body if hasattr(e, "body") else e
             msg = "Failed to patch object: {0}".format(reason)
@@ -330,123 +332,124 @@ class K8sService:
             result["resources"].append(hide_fields(res, hidden_fields))
         return result
 
-    def create(self, resource: Resource, definition: Dict) -> Dict:
+    def create(self, resource: Resource, definition: Dict) -> Tuple[Dict, List[str]]:
         namespace = definition["metadata"].get("namespace")
         name = definition["metadata"].get("name")
 
         if self._client_side_dry_run:
-            k8s_obj = _encode_stringdata(definition)
-        else:
-            try:
-                k8s_obj = self.client.create(
-                    resource, definition, namespace=namespace
-                ).to_dict()
-            except ConflictError:
-                # Some resources, like ProjectRequests, can't be created multiple times,
-                # because the resources that they create don't match their kind
-                # In this case we'll mark it as unchanged and warn the user
-                self.module.warn(
-                    "{0} was not found, but creating it returned a 409 Conflict error. This can happen \
-                            if the resource you are creating does not directly create a resource of the same kind.".format(
-                        name
-                    )
+            return _encode_stringdata(definition), []
+
+        try:
+            return decode_response(
+                self.client.create(
+                    resource, definition, namespace=namespace, serialize=False
                 )
-                return dict()
-            except Exception as e:
-                reason = e.body if hasattr(e, "body") else e
-                msg = "Failed to create object: {0}".format(reason)
-                raise CoreException(msg) from e
-        return k8s_obj
+            )
+        except ConflictError:
+            # Some resources, like ProjectRequests, can't be created multiple times,
+            # because the resources that they create don't match their kind
+            # In this case we'll mark it as unchanged and warn the user
+            self.module.warn(
+                "{0} was not found, but creating it returned a 409 Conflict error. This can happen \
+                        if the resource you are creating does not directly create a resource of the same kind.".format(
+                    name
+                )
+            )
+            return dict(), []
+        except Exception as e:
+            reason = e.body if hasattr(e, "body") else e
+            msg = "Failed to create object: {0}".format(reason)
+            raise CoreException(msg) from e
 
     def apply(
         self,
         resource: Resource,
         definition: Dict,
         existing: Optional[ResourceInstance] = None,
-    ) -> Dict:
+    ) -> Tuple[Dict, List[str]]:
         namespace = definition["metadata"].get("namespace")
 
         server_side_apply = self.module.params.get("server_side_apply")
         if server_side_apply:
             requires("kubernetes", "19.15.0", reason="to use server side apply")
+
         if self._client_side_dry_run:
             ignored, patch = apply_object(resource, _encode_stringdata(definition))
             if existing:
-                k8s_obj = dict_merge(existing.to_dict(), patch)
+                return dict_merge(existing.to_dict(), patch), []
             else:
-                k8s_obj = patch
-        else:
-            try:
-                params = {}
-                if server_side_apply:
-                    params["server_side"] = True
-                    params.update(server_side_apply)
-                k8s_obj = self.client.apply(
-                    resource, definition, namespace=namespace, **params
-                ).to_dict()
-            except Exception as e:
-                reason = e.body if hasattr(e, "body") else e
-                msg = "Failed to apply object: {0}".format(reason)
-                raise CoreException(msg) from e
-        return k8s_obj
+                return patch, []
+
+        try:
+            params = {}
+            if server_side_apply:
+                params["server_side"] = True
+                params.update(server_side_apply)
+            return decode_response(
+                self.client.apply(
+                    resource, definition, namespace=namespace, serialize=False, **params
+                )
+            )
+        except Exception as e:
+            reason = e.body if hasattr(e, "body") else e
+            msg = "Failed to apply object: {0}".format(reason)
+            raise CoreException(msg) from e
 
     def replace(
         self,
         resource: Resource,
         definition: Dict,
         existing: ResourceInstance,
-    ) -> Dict:
+    ) -> Tuple[Dict, List[str]]:
         append_hash = self.module.params.get("append_hash", False)
         name = definition["metadata"].get("name")
         namespace = definition["metadata"].get("namespace")
 
         if self._client_side_dry_run:
-            k8s_obj = _encode_stringdata(definition)
-        else:
-            try:
-                k8s_obj = self.client.replace(
+            return _encode_stringdata(definition), []
+
+        try:
+            return decode_response(
+                self.client.replace(
                     resource,
                     definition,
                     name=name,
                     namespace=namespace,
                     append_hash=append_hash,
-                ).to_dict()
-            except Exception as e:
-                reason = e.body if hasattr(e, "body") else e
-                msg = "Failed to replace object: {0}".format(reason)
-                raise CoreException(msg) from e
-        return k8s_obj
+                    serialize=False,
+                )
+            )
+        except Exception as e:
+            reason = e.body if hasattr(e, "body") else e
+            msg = "Failed to replace object: {0}".format(reason)
+            raise CoreException(msg) from e
 
     def update(
         self, resource: Resource, definition: Dict, existing: ResourceInstance
-    ) -> Dict:
+    ) -> Tuple[Dict, List[str]]:
         name = definition["metadata"].get("name")
         namespace = definition["metadata"].get("namespace")
 
         if self._client_side_dry_run:
-            k8s_obj = dict_merge(existing.to_dict(), _encode_stringdata(definition))
-        else:
-            exception = None
-            for merge_type in self.module.params.get("merge_type") or [
-                "strategic-merge",
-                "merge",
-            ]:
-                try:
-                    k8s_obj = self.patch_resource(
-                        resource,
-                        definition,
-                        name,
-                        namespace,
-                        merge_type=merge_type,
-                    )
-                    exception = None
-                except CoreException as e:
-                    exception = e
-                    continue
-                break
-            if exception:
-                raise exception
-        return k8s_obj
+            return dict_merge(existing.to_dict(), _encode_stringdata(definition)), []
+
+        exception = None
+        for merge_type in self.module.params.get("merge_type") or [
+            "strategic-merge",
+            "merge",
+        ]:
+            try:
+                return self.patch_resource(
+                    resource,
+                    definition,
+                    name,
+                    namespace,
+                    merge_type=merge_type,
+                )
+            except CoreException as e:
+                exception = e
+                continue
+        raise exception
 
     def delete(
         self,
@@ -543,3 +546,83 @@ def hide_field(definition: dict, hidden_field: str) -> dict:
         else:
             del definition[split[0]]
     return definition
+
+
+def decode_response(resp) -> Tuple[Dict, List[str]]:
+    """
+    This function decodes unserialized responses from the Kubernetes python
+    client and decodes the RFC2616 14.46 warnings found in the response
+    headers.
+    """
+    obj = ResourceInstance(None, loads(resp.data.decode("utf8"))).to_dict()
+    warnings = []
+    if (
+        resp.headers is not None
+        and "warning" in resp.headers
+        and resp.headers["warning"] is not None
+    ):
+        warnings = resp.headers["warning"].split(", ")
+    return obj, decode_warnings(warnings)
+
+
+def decode_warnings(warnings: str) -> List[str]:
+    """
+    This function decodes RFC2616 14.46 warnings in a simplified way, where
+    only the warn-texts are returned in a list.
+    """
+    p = compile('\\d{3} .+ (".+")')
+
+    decoded = []
+    for warning in warnings:
+        m = p.match(warning)
+        if m:
+            try:
+                parsed, unused = parse_quoted_string(m.group(1))
+                decoded.append(parsed)
+            except ValueError:
+                continue
+
+    return decoded
+
+
+def parse_quoted_string(quoted_string: str) -> Tuple[str, str]:
+    """
+    This function was adapted from:
+    https://github.com/kubernetes/apimachinery/blob/bb8822152cabfb4f34dbc26270f874ce53db50de/pkg/util/net/http.go#L609
+    """
+    if len(quoted_string) == 0:
+        raise ValueError("invalid quoted string: 0-length")
+
+    if quoted_string[0] != '"':
+        raise ValueError("invalid quoted string: missing initial quote")
+
+    quoted_string = quoted_string[1:]
+    remainder = ""
+    escaping = False
+    closed_quote = False
+    result = []
+
+    for i, b in enumerate(quoted_string):
+        if b == '"':
+            if escaping:
+                result.append(b)
+                escaping = False
+            else:
+                closed_quote = True
+                remainder_start = i + 1
+                remainder = quoted_string[remainder_start:].strip()
+                break
+        elif b == "\\":
+            if escaping:
+                result.append(b)
+                escaping = False
+            else:
+                escaping = True
+        else:
+            result.append(b)
+            escaping = False
+
+    if not closed_quote:
+        raise ValueError("invalid quoted string: missing closing quote")
+
+    return "".join(result), remainder