Replicate base resource for lists functionality (#89)

* Replicate base resource for lists functionality

This replicates specific functionality from the openshift client to more
reliably retrieve the base resource from a resource list.

* Add changelog fragment

plugins/module_utils/cache.py

@@ -1,55 +0,0 @@
-# Copyright [2017] [Red Hat, Inc.]
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#    http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-
-from __future__ import absolute_import, division, print_function
-__metaclass__ = type
-
-import os
-
-from ansible.module_utils.six import PY3
-
-
-def get_user():
-    if hasattr(os, 'getlogin'):
-        try:
-            user = os.getlogin()
-            if user:
-                return str(user)
-        except OSError:
-            pass
-    if hasattr(os, 'getuid'):
-        try:
-            user = os.getuid()
-            if user:
-                return str(user)
-        except OSError:
-            pass
-    user = os.environ.get("USERNAME")
-    if user:
-        return str(user)
-    return None
-
-
-def get_default_cache_id(client):
-    user = get_user()
-    if user:
-        cache_id = "{0}-{1}".format(client.configuration.host, user)
-    else:
-        cache_id = client.configuration.host
-
-    if PY3:
-        return cache_id.encode('utf-8')
-
-    return cache_id

plugins/module_utils/client/discovery.py

@@ -0,0 +1,154 @@
+# Copyright [2017] [Red Hat, Inc.]
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+import json
+import os
+from collections import defaultdict
+import hashlib
+import tempfile
+
+import kubernetes.dynamic
+import kubernetes.dynamic.discovery
+from kubernetes import __version__
+from kubernetes.dynamic.exceptions import ServiceUnavailableError
+
+from ansible_collections.kubernetes.core.plugins.module_utils.client.resource import ResourceList
+
+
+class Discoverer(kubernetes.dynamic.discovery.Discoverer):
+    def __init__(self, client, cache_file):
+        self.client = client
+        default_cache_file_name = 'k8srcp-{0}.json'.format(hashlib.sha256(self.__get_default_cache_id()).hexdigest())
+        self.__cache_file = cache_file or os.path.join(tempfile.gettempdir(), default_cache_file_name)
+        self.__init_cache()
+
+    def __get_default_cache_id(self):
+        user = self.__get_user()
+        if user:
+            cache_id = "{0}-{1}".format(self.client.configuration.host, user)
+        else:
+            cache_id = self.client.configuration.host
+        return cache_id.encode('utf-8')
+
+    def __get_user(self):
+        # This is intended to provide a portable method for getting a username.
+        # It could, and maybe should, be replaced by getpass.getuser() but, due
+        # to a lack of portability testing the original code is being left in
+        # place.
+        if hasattr(os, 'getlogin'):
+            try:
+                user = os.getlogin()
+                if user:
+                    return str(user)
+            except OSError:
+                pass
+        if hasattr(os, 'getuid'):
+            try:
+                user = os.getuid()
+                if user:
+                    return str(user)
+            except OSError:
+                pass
+        user = os.environ.get("USERNAME")
+        if user:
+            return str(user)
+        return None
+
+    def __init_cache(self, refresh=False):
+        if refresh or not os.path.exists(self.__cache_file):
+            self._cache = {'library_version': __version__}
+            refresh = True
+        else:
+            try:
+                with open(self.__cache_file, 'r') as f:
+                    self._cache = json.load(f, cls=CacheDecoder(self.client))
+                if self._cache.get('library_version') != __version__:
+                    # Version mismatch, need to refresh cache
+                    self.invalidate_cache()
+            except Exception:
+                self.invalidate_cache()
+        self._load_server_info()
+        self.discover()
+        if refresh:
+            self._write_cache()
+
+    def get_resources_for_api_version(self, prefix, group, version, preferred):
+        """ returns a dictionary of resources associated with provided (prefix, group, version)"""
+
+        resources = defaultdict(list)
+        subresources = defaultdict(dict)
+
+        path = '/'.join(filter(None, [prefix, group, version]))
+        try:
+            resources_response = self.client.request('GET', path).resources or []
+        except ServiceUnavailableError:
+            resources_response = []
+
+        resources_raw = list(filter(lambda resource: '/' not in resource['name'], resources_response))
+        subresources_raw = list(filter(lambda resource: '/' in resource['name'], resources_response))
+        for subresource in subresources_raw:
+            resource, name = subresource['name'].split('/')
+            subresources[resource][name] = subresource
+
+        for resource in resources_raw:
+            # Prevent duplicate keys
+            for key in ('prefix', 'group', 'api_version', 'client', 'preferred'):
+                resource.pop(key, None)
+
+            resourceobj = kubernetes.dynamic.Resource(
+                prefix=prefix,
+                group=group,
+                api_version=version,
+                client=self.client,
+                preferred=preferred,
+                subresources=subresources.get(resource['name']),
+                **resource
+            )
+            resources[resource['kind']].append(resourceobj)
+
+            resource_lookup = {
+                'prefix': prefix,
+                'group': group,
+                'api_version': version,
+                'kind': resourceobj.kind,
+                'name': resourceobj.name
+            }
+            resource_list = ResourceList(self.client, group=group, api_version=version, base_kind=resource['kind'], base_resource_lookup=resource_lookup)
+            resources[resource_list.kind].append(resource_list)
+        return resources
+
+
+class LazyDiscoverer(Discoverer, kubernetes.dynamic.LazyDiscoverer):
+    def __init__(self, client, cache_file):
+        Discoverer.__init__(self, client, cache_file)
+        self.__update_cache = False
+
+
+class CacheDecoder(json.JSONDecoder):
+    def __init__(self, client, *args, **kwargs):
+        self.client = client
+        json.JSONDecoder.__init__(self, object_hook=self.object_hook, *args, **kwargs)
+
+    def object_hook(self, obj):
+        if '_type' not in obj:
+            return obj
+        _type = obj.pop('_type')
+        if _type == 'Resource':
+            return kubernetes.dynamic.Resource(client=self.client, **obj)
+        elif _type == 'ResourceList':
+            return ResourceList(self.client, **obj)
+        elif _type == 'ResourceGroup':
+            return kubernetes.dynamic.discovery.ResourceGroup(obj['preferred'], resources=self.object_hook(obj['resources']))
+        return obj

plugins/module_utils/client/resource.py

@@ -0,0 +1,49 @@
+# Copyright [2017] [Red Hat, Inc.]
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+
+import kubernetes.dynamic
+
+
+class ResourceList(kubernetes.dynamic.resource.ResourceList):
+    def __init__(self, client, group='', api_version='v1', base_kind='', kind=None, base_resource_lookup=None):
+        self.client = client
+        self.group = group
+        self.api_version = api_version
+        self.kind = kind or '{0}List'.format(base_kind)
+        self.base_kind = base_kind
+        self.base_resource_lookup = base_resource_lookup
+        self.__base_resource = None
+
+    def base_resource(self):
+        if self.__base_resource:
+            return self.__base_resource
+        elif self.base_resource_lookup:
+            self.__base_resource = self.client.resources.get(**self.base_resource_lookup)
+            return self.__base_resource
+        return None
+
+    def to_dict(self):
+        return {
+            '_type': 'ResourceList',
+            'group': self.group,
+            'api_version': self.api_version,
+            'kind': self.kind,
+            'base_kind': self.base_kind,
+            'base_resource_lookup': self.base_resource_lookup
+        }

plugins/module_utils/common.py

@@ -23,14 +23,12 @@ import time
 import os
 import traceback
 import sys
-import tempfile
 import hashlib
 from datetime import datetime
 from distutils.version import LooseVersion
 
 from ansible_collections.kubernetes.core.plugins.module_utils.args_common import (AUTH_ARG_MAP, AUTH_ARG_SPEC, AUTH_PROXY_HEADERS_SPEC)
 from ansible_collections.kubernetes.core.plugins.module_utils.hashes import generate_hash
-from ansible_collections.kubernetes.core.plugins.module_utils.cache import get_default_cache_id
 
 from ansible.module_utils.basic import missing_required_lib
 from ansible.module_utils.six import iteritems, string_types
@@ -56,6 +54,7 @@ except ImportError as e:
 IMP_K8S_CLIENT = None
 try:
     from ansible_collections.kubernetes.core.plugins.module_utils.k8sdynamicclient import K8SDynamicClient
+    from ansible_collections.kubernetes.core.plugins.module_utils.client.discovery import LazyDiscoverer
     IMP_K8S_CLIENT = True
 except ImportError as e:
     IMP_K8S_CLIENT = False
@@ -214,15 +213,8 @@ def get_api_client(module=None, **kwargs):
         client = get_api_client._pool[digest]
         return client
 
-    def generate_cache_file(kubeclient):
-        cache_file_name = 'k8srcp-{0}.json'.format(hashlib.sha256(get_default_cache_id(kubeclient)).hexdigest())
-        return os.path.join(tempfile.gettempdir(), cache_file_name)
-
-    kubeclient = kubernetes.client.ApiClient(configuration)
-    cache_file = generate_cache_file(kubeclient)
-
     try:
-        client = K8SDynamicClient(kubeclient, cache_file)
+        client = K8SDynamicClient(kubernetes.client.ApiClient(configuration), discoverer=LazyDiscoverer)
     except Exception as err:
         _raise_or_fail(err, 'Failed to get client due to %s')