Add merge_type parameter to k8s module (#42219)

Allows patching of custom Kubernetes resources that
don't support strategic merge patching

Check that openshift module supports content_type param
(requires version newer than 0.6.0)

lib/ansible/module_utils/k8s/common.py

@@ -1,5 +1,4 @@
-#
-#  Copyright 2018 Red Hat | Ansible
+# Copyright 2018 Red Hat | Ansible
 #
 # This file is part of Ansible
 #
@@ -27,6 +26,7 @@ from ansible.module_utils.six import iteritems, string_types
 
 try:
     import kubernetes
+    import openshift
     from openshift.dynamic import DynamicClient
     from openshift.dynamic.exceptions import ResourceNotFoundError, ResourceNotUniqueError
     HAS_K8S_MODULE_HELPER = True
@@ -258,6 +258,7 @@ class KubernetesAnsibleModule(AnsibleModule, K8sAnsibleMixin):
 
         if not HAS_K8S_MODULE_HELPER:
             self.fail_json(msg="This module requires the OpenShift Python client. Try `pip install openshift`")
+        self.openshift_version = openshift.__version__
 
         if not HAS_YAML:
             self.fail_json(msg="This module requires PyYAML. Try `pip install PyYAML`")

lib/ansible/module_utils/k8s/raw.py

@@ -18,7 +18,8 @@
 
 from __future__ import absolute_import, division, print_function
 
-
+import copy
+from ansible.module_utils.k8s.common import AUTH_ARG_SPEC, COMMON_ARG_SPEC
 from ansible.module_utils.six import string_types
 from ansible.module_utils.k8s.common import KubernetesAnsibleModule
 from ansible.module_utils.common.dict_transformations import dict_merge
@@ -34,6 +35,13 @@ except ImportError:
 
 class KubernetesRawModule(KubernetesAnsibleModule):
 
+    @property
+    def argspec(self):
+        argument_spec = copy.deepcopy(COMMON_ARG_SPEC)
+        argument_spec.update(copy.deepcopy(AUTH_ARG_SPEC))
+        argument_spec['merge_type'] = dict(choices=['json', 'merge', 'strategic-merge'])
+        return argument_spec
+
     def __init__(self, *args, **kwargs):
         self.client = None
 
@@ -203,7 +211,15 @@ class KubernetesRawModule(KubernetesAnsibleModule):
                 k8s_obj = dict_merge(existing.to_dict(), definition)
             else:
                 try:
-                    k8s_obj = resource.patch(definition, name=name, namespace=namespace).to_dict()
+                    params = dict(name=name, namespace=namespace)
+                    if self.params['merge_type']:
+                        from distutils.version import LooseVersion
+                        if LooseVersion(self.openshift_version) < LooseVersion("0.6.2"):
+                            self.fail_json(msg="openshift >= 0.6.2 is required for merge_type")
+                        params['content_type'] = 'application/{0}-patch+json'.format(self.params['merge_type'])
+                    k8s_obj = resource.patch(definition, **params).to_dict()
+                    match, diffs = self.diff_objects(existing.to_dict(), k8s_obj)
+                    result['result'] = k8s_obj
                 except DynamicApiError as exc:
                     self.fail_json(msg="Failed to patch object: {0}".format(exc.body),
                                    error=exc.status, status=exc.status, reason=exc.reason)

lib/ansible/modules/clustering/k8s/k8s.py

@@ -40,6 +40,21 @@ extends_documentation_fragment:
   - k8s_resource_options
   - k8s_auth_options
 
+options:
+  merge_type:
+    description:
+    - Whether to override the default patch merge approach with a specific type. By the default, the strategic
+      merge will typically be used.
+    - For example, Custom Resource Definitions typically aren't updatable by the usual strategic merge. You may
+      want to use C(merge) if you see "strategic merge patch format is not supported"
+    - See U(https://kubernetes.io/docs/tasks/run-application/update-api-object-kubectl-patch/#use-a-json-merge-patch-to-update-a-deployment)
+    - Requires openshift >= 0.6.2
+    choices:
+    - json
+    - merge
+    - strategic-merge
+    version_added: "2.7"
+
 requirements:
   - "python >= 2.7"
   - "openshift >= 0.6"