k8s - add label_selectors options (#158)

k8s - add label_selectors options

SUMMARY
k8s now support label_selectors options same as k8s_info

Resolves #43

ISSUE TYPE


Feature Pull Request


COMPONENT NAME

k8s

Reviewed-by: Mike Graves <mgraves@redhat.com>
Reviewed-by: None <None>

plugins/module_utils/selector.py

@@ -0,0 +1,71 @@
+# Copyright [2021] [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 re
+
+
+class Selector(object):
+
+    equality_based_operators = ('==', '!=', '=')
+
+    def __init__(self, data):
+        self._operator = None
+        self._data = None
+        if not self.parse_set_based_requirement(data):
+            no_whitespace_data = data.replace(" ", "")
+            for op in self.equality_based_operators:
+                idx = no_whitespace_data.find(op)
+                if idx != -1:
+                    self._operator = "in" if op == '==' or op == '=' else "notin"
+                    self._key = no_whitespace_data[0:idx]
+                    self._data = [no_whitespace_data[idx + len(op):]]
+                    break
+
+    def parse_set_based_requirement(self, data):
+        m = re.match(r'( *)([a-z0-9A-Z][a-z0-9A-Z\._-]*[a-z0-9A-Z])( +)(notin|in)( +)\((.*)\)( *)', data)
+        if m:
+            self._set_based_requirement = True
+            self._key = m.group(2)
+            self._operator = m.group(4)
+            self._data = [x.replace(' ', '') for x in m.group(6).split(',') if x != '']
+            return True
+        elif all([x not in data for x in self.equality_based_operators]):
+            self._key = data.rstrip(" ").lstrip(" ")
+            if self._key.startswith("!"):
+                self._key = self._key[1:].lstrip(" ")
+                self._operator = "!"
+            return True
+        return False
+
+    def isMatch(self, labels):
+        if self._operator == "in":
+            return self._key in labels and labels.get(self._key) in self._data
+        elif self._operator == "notin":
+            return self._key not in labels or labels.get(self._key) not in self._data
+        else:
+            return self._key not in labels if self._operator == "!" else self._key in labels
+
+
+class LabelSelectorFilter(object):
+
+    def __init__(self, label_selectors):
+        self.selectors = [Selector(data) for data in label_selectors]
+
+    def isMatching(self, definition):
+        if "metadata" not in definition or "labels" not in definition['metadata']:
+            return False
+        labels = definition['metadata']['labels']
+        if not isinstance(labels, dict):
+            return None
+        return all([sel.isMatch(labels) for sel in self.selectors])