Initial work K8S client class (#276)

Initial work K8S client class

SUMMARY

Initial work on K8SClient Class.

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

plugins/module_utils/k8s/client.py

@@ -0,0 +1,253 @@
+# Copyright: (c) 2021, Red Hat | Ansible
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+import os
+import hashlib
+from distutils.version import LooseVersion
+from typing import Any, Dict, List, Optional
+
+from ansible.module_utils.six import iteritems, string_types
+
+from ansible_collections.kubernetes.core.plugins.module_utils.args_common import (
+    AUTH_ARG_MAP,
+    AUTH_ARG_SPEC,
+    AUTH_PROXY_HEADERS_SPEC,
+)
+
+try:
+    from ansible_collections.kubernetes.core.plugins.module_utils import (
+        k8sdynamicclient,
+    )
+    from ansible_collections.kubernetes.core.plugins.module_utils.client.discovery import (
+        LazyDiscoverer,
+    )
+except ImportError:
+    # Handled in module setup
+    pass
+
+try:
+    import kubernetes
+except ImportError:
+    # Handled in module setup
+    pass
+
+try:
+    import urllib3
+
+    urllib3.disable_warnings()
+except ImportError:
+    # Handled in module setup
+    pass
+
+
+module = None
+_pool = {}
+
+
+def _requires_kubernetes_at_least(version: str):
+    if module:
+        module.requires("kubernetes", version)
+    else:
+        if LooseVersion(kubernetes.__version__) < LooseVersion(version):
+            raise Exception(
+                f"kubernetes >= {version} is required to use in-memory kubeconfig."
+            )
+
+
+def _create_auth_spec(module=None, **kwargs) -> Dict:
+    auth: Dict = {}
+    # If authorization variables aren't defined, look for them in environment variables
+    for true_name, arg_name in AUTH_ARG_MAP.items():
+        if module and module.params.get(arg_name) is not None:
+            auth[true_name] = module.params.get(arg_name)
+        elif arg_name in kwargs and kwargs.get(arg_name) is not None:
+            auth[true_name] = kwargs.get(arg_name)
+        elif arg_name == "proxy_headers":
+            # specific case for 'proxy_headers' which is a dictionary
+            proxy_headers = {}
+            for key in AUTH_PROXY_HEADERS_SPEC.keys():
+                env_value = os.getenv(
+                    "K8S_AUTH_PROXY_HEADERS_{0}".format(key.upper()), None
+                )
+                if env_value is not None:
+                    if AUTH_PROXY_HEADERS_SPEC[key].get("type") == "bool":
+                        env_value = env_value.lower() not in ["0", "false", "no"]
+                    proxy_headers[key] = env_value
+            if proxy_headers is not {}:
+                auth[true_name] = proxy_headers
+        else:
+            env_value = os.getenv(
+                "K8S_AUTH_{0}".format(arg_name.upper()), None
+            ) or os.getenv("K8S_AUTH_{0}".format(true_name.upper()), None)
+            if env_value is not None:
+                if AUTH_ARG_SPEC[arg_name].get("type") == "bool":
+                    env_value = env_value.lower() not in ["0", "false", "no"]
+                auth[true_name] = env_value
+
+    return auth
+
+
+def _load_config(auth: Dict) -> None:
+    kubeconfig = auth.get("kubeconfig")
+    optional_arg = {
+        "context": auth.get("context"),
+        "persist_config": auth.get("persist_config"),
+    }
+    if kubeconfig:
+        if isinstance(kubeconfig, string_types):
+            kubernetes.config.load_kube_config(config_file=kubeconfig, **optional_arg)
+        elif isinstance(kubeconfig, dict):
+            _requires_kubernetes_at_least("17.17.0")
+            kubernetes.config.load_kube_config_from_dict(
+                config_dict=kubeconfig, **optional_arg
+            )
+    else:
+        kubernetes.config.load_kube_config(config_file=None, **optional_arg)
+
+
+def _create_configuration(auth: Dict):
+    def auth_set(*names: list) -> bool:
+        return all(auth.get(name) for name in names)
+
+    if auth_set("host"):
+        # Removing trailing slashes if any from hostname
+        auth["host"] = auth.get("host").rstrip("/")
+
+    if auth_set("username", "password", "host") or auth_set("api_key", "host"):
+        # We have enough in the parameters to authenticate, no need to load incluster or kubeconfig
+        pass
+    elif auth_set("kubeconfig") or auth_set("context"):
+        try:
+            _load_config(auth)
+        except Exception as err:
+            raise err
+
+    else:
+        # First try to do incluster config, then kubeconfig
+        try:
+            kubernetes.config.load_incluster_config()
+        except kubernetes.config.ConfigException:
+            try:
+                _load_config(auth)
+            except Exception as err:
+                raise err
+
+    # Override any values in the default configuration with Ansible parameters
+    # As of kubernetes-client v12.0.0, get_default_copy() is required here
+    try:
+        configuration = kubernetes.client.Configuration().get_default_copy()
+    except AttributeError:
+        configuration = kubernetes.client.Configuration()
+
+    for key, value in iteritems(auth):
+        if key in AUTH_ARG_MAP.keys() and value is not None:
+            if key == "api_key":
+                setattr(
+                    configuration, key, {"authorization": "Bearer {0}".format(value)}
+                )
+            elif key == "proxy_headers":
+                headers = urllib3.util.make_headers(**value)
+                setattr(configuration, key, headers)
+            else:
+                setattr(configuration, key, value)
+
+    return configuration
+
+
+def _configuration_digest(configuration) -> str:
+    m = hashlib.sha256()
+    for k in AUTH_ARG_MAP:
+        if not hasattr(configuration, k):
+            v = None
+        else:
+            v = getattr(configuration, k)
+        if v and k in ["ssl_ca_cert", "cert_file", "key_file"]:
+            with open(str(v), "r") as fd:
+                content = fd.read()
+                m.update(content.encode())
+        else:
+            m.update(str(v).encode())
+    digest = m.hexdigest()
+
+    return digest
+
+
+def cache(func):
+    def wrapper(*args):
+        client = None
+        digest = _configuration_digest(*args)
+        if digest in _pool:
+            client = _pool[digest]
+        else:
+            client = func(*args)
+            _pool[digest] = client
+
+        return client
+
+    return wrapper
+
+
+@cache
+def create_api_client(configuration):
+    return k8sdynamicclient.K8SDynamicClient(
+        kubernetes.client.ApiClient(configuration), discoverer=LazyDiscoverer
+    )
+
+
+class K8SClient:
+    """A Client class for K8S modules.
+
+    This class has the primary purpose to proxy the kubernetes client and resource objects.
+    If there is a need for other methods or attributes to be proxied, they can be added here.
+    """
+
+    def __init__(self, configuration, client, dry_run: bool = False) -> None:
+        self.configuration = configuration
+        self.client = client
+        self.dry_run = dry_run
+
+    @property
+    def resources(self) -> List[Any]:
+        return self.client.resources
+
+    def _ensure_dry_run(self, params: Dict) -> Dict:
+        if self.dry_run:
+            params["dry_run"] = True
+        return params
+
+    def validate(self, resource, **params):
+        pass
+
+    def get(self, resource, **params):
+        return resource.get(**params)
+
+    def delete(self, resource, **params):
+        return resource.delete(**self._ensure_dry_run(params))
+
+    def apply(self, resource, definition, namespace, **params):
+        return resource.apply(
+            definition, namespace=namespace, **self._ensure_dry_run(params)
+        )
+
+    def create(self, resource, definition, **params):
+        return resource.create(definition, **self._ensure_dry_run(params))
+
+    def replace(self, resource, definition, **params):
+        return resource.replace(definition, **self._ensure_dry_run(params))
+
+    def patch(self, resource, definition, **params):
+        return resource.patch(definition, **self._ensure_dry_run(params))
+
+
+def get_api_client(module=None, **kwargs: Optional[Any]) -> K8SClient:
+    auth_spec = _create_auth_spec(module, **kwargs)
+    configuration = _create_configuration(auth_spec)
+    client = create_api_client(configuration)
+
+    k8s_client = K8SClient(
+        configuration=configuration,
+        client=client,
+        dry_run=module.params.get("dry_run", False),
+    )
+
+    return k8s_client.client