add ForemanApi

Author: evgeni

apypie/__init__.py

@@ -11,5 +11,6 @@
 from apypie.example import Example
 from apypie.param import Param
 from apypie.inflector import Inflector
+from apypie.foreman import ForemanApi, ForemanApiException
 
-__all__ = ['Api', 'Resource', 'Route', 'Action', 'Example', 'Param', 'Inflector']
+__all__ = ['Api', 'Resource', 'Route', 'Action', 'Example', 'Param', 'Inflector', 'ForemanApi', 'ForemanApiException']

apypie/foreman.py

@@ -0,0 +1,228 @@
+"""
+Apypie Foreman module
+
+opinionated helpers to use Apypie with Foreman
+"""
+import time
+
+try:
+    from typing import cast, Optional, Set, Tuple
+except ImportError:
+    pass
+
+from apypie.api import Api
+
+from apypie.resource import Resource  # pylint: disable=unused-import
+
+# Foreman supports "per_page=all" since 2.2 (https://projects.theforeman.org/issues/29909)
+# But plugins, especially Katello, do not: https://github.com/Katello/katello/pull/11126
+# To still be able to fetch all results without pagination, we have this constant for now
+PER_PAGE = 2 << 31
+
+
+class ForemanApiException(Exception):
+    """
+    General Exception, raised by any issue in ForemanApi
+    """
+
+    def __init__(self, msg, error=None):
+        if error:
+            super().__init__(f'{msg} - {error}')
+        else:
+            super().__init__(msg)
+
+    @classmethod
+    def from_exception(cls, exc, msg):
+        """
+        Create a ForemanException from any other Exception
+
+        Especially useful to gather the error message from HTTP responses.
+        """
+        error = None
+        if hasattr(exc, 'response') and exc.response is not None:
+            try:
+                response = exc.response.json()
+                if 'error' in response:
+                    error = response['error']
+                else:
+                    error = response
+            except Exception:  # pylint: disable=broad-except
+                error = exc.response.text
+        return cls(msg=msg, error=error)
+
+
+class ForemanApi(Api):
+    """
+    `apypie.Api` with default settings and helper functions for Foreman
+
+    Usage::
+
+      >>> import apypie
+      >>> api = apypie.ForemanApi(uri='https://foreman.example.com', username='admin', password='changeme')
+    """
+
+    def __init__(self, **kwargs):
+        self.task_timeout = kwargs.pop('task_timeout', 60)
+        self.task_poll = 4
+        kwargs['api_version'] = 2
+        super().__init__(**kwargs)
+
+    def _resource(self, resource: str) -> 'Resource':
+        if resource not in self.resources:
+            raise ForemanApiException(msg=f"The server doesn't know about {resource}, is the right plugin installed?")
+        return self.resource(resource)
+
+    def _resource_call(self, resource: str, *args, **kwargs) -> Optional[dict]:
+        return self._resource(resource).call(*args, **kwargs)
+
+    def _resource_prepare_params(self, resource: str, action: str, params: dict) -> dict:
+        api_action = self._resource(resource).action(action)
+        return api_action.prepare_params(params)
+
+    def resource_action(self, resource: str, action: str, params: dict, options=None, data=None, files=None,  # pylint: disable=too-many-arguments
+                        ignore_task_errors: bool = False) -> Optional[dict]:
+        """
+        Perform a generic action on a resource
+
+        Will wait for tasks if the action returns one
+        """
+        resource_payload = self._resource_prepare_params(resource, action, params)
+        if options is None:
+            options = {}
+        try:
+            result = self._resource_call(resource, action, resource_payload, options=options, data=data, files=files)
+            is_foreman_task = isinstance(result, dict) and 'action' in result and 'state' in result and 'started_at' in result
+            if result and is_foreman_task:
+                result = self.wait_for_task(result, ignore_errors=ignore_task_errors)
+        except Exception as exc:
+            msg = f'Error while performing {action} on {resource}: {exc}'
+            raise ForemanApiException.from_exception(exc, msg) from exc
+        return result
+
+    def wait_for_task(self, task: dict, ignore_errors: bool = False) -> dict:
+        """
+        Wait for a foreman-tasks task, polling it every ``self.task_poll`` seconds.
+
+        Will raise a ForemanApiException when task has not finished in ``self.task_timeout`` seconds.
+        """
+        duration = self.task_timeout
+        while task['state'] not in ['paused', 'stopped']:
+            duration -= self.task_poll
+            if duration <= 0:
+                raise ForemanApiException(msg=f"Timeout waiting for Task {task['id']}")
+            time.sleep(self.task_poll)
+
+            resource_payload = self._resource_prepare_params('foreman_tasks', 'show', {'id': task['id']})
+            task = cast(dict, self._resource_call('foreman_tasks', 'show', resource_payload))
+        if not ignore_errors and task['result'] != 'success':
+            msg = f"Task {task['action']}({task['id']}) did not succeed. Task information: {task['humanized']['errors']}"
+            raise ForemanApiException(msg=msg)
+        return task
+
+    def show(self, resource: str, resource_id: int, params: Optional[dict] = None) -> Optional[dict]:
+        """
+        Execute the ``show`` action on an entity.
+
+        :param resource: Plural name of the api resource to show
+        :param resource_id: The ID of the entity to show
+        :param params: Lookup parameters (i.e. parent_id for nested entities)
+
+        :return: The entity
+        """
+        payload = {'id': resource_id}
+        if params:
+            payload.update(params)
+        return self.resource_action(resource, 'show', payload)
+
+    def list(self, resource: str, search: Optional[str] = None, params: Optional[dict] = None) -> list:
+        """
+        Execute the ``index`` action on an resource.
+
+        :param resource: Plural name of the api resource to show
+        :param search: Search string as accepted by the API to limit the results
+        :param params: Lookup parameters (i.e. parent_id for nested entities)
+
+        :return: List of results
+        """
+        payload: dict = {'per_page': PER_PAGE}
+        if search is not None:
+            payload['search'] = search
+        if params:
+            payload.update(params)
+
+        result = self.resource_action(resource, 'index', payload)
+        if result:
+            return result['results']
+        return []
+
+    def create(self, resource: str, desired_entity: dict, params: Optional[dict] = None) -> Optional[dict]:
+        """
+        Create entity with given properties
+
+        :param resource: Plural name of the api resource to manipulate
+        :param desired_entity: Desired properties of the entity
+        :param params: Lookup parameters (i.e. parent_id for nested entities)
+
+        :return: The new current state of the entity
+        """
+        payload = desired_entity.copy()
+        if params:
+            payload.update(params)
+        return self.resource_action(resource, 'create', payload)
+
+    def update(self, resource: str, desired_entity: dict, params: Optional[dict] = None) -> Optional[dict]:
+        """
+        Update entity with given properties
+
+        :param resource: Plural name of the api resource to manipulate
+        :param desired_entity: Desired properties of the entity
+        :param params: Lookup parameters (i.e. parent_id for nested entities)
+
+        :return: The new current state of the entity
+        """
+        payload = desired_entity.copy()
+        if params:
+            payload.update(params)
+        return self.resource_action(resource, 'update', payload)
+
+    def delete(self, resource: str, current_entity: dict, params: Optional[dict] = None) -> None:
+        """
+        Delete a given entity
+
+        :param resource: Plural name of the api resource to manipulate
+        :param current_entity: Current properties of the entity
+        :param params: Lookup parameters (i.e. parent_id for nested entities)
+
+        :return: The new current state of the entity
+        """
+        payload = {'id': current_entity['id']}
+        if params:
+            payload.update(params)
+        entity = self.resource_action(resource, 'destroy', payload)
+
+        # this is a workaround for https://projects.theforeman.org/issues/26937
+        if entity and isinstance(entity, dict) and 'error' in entity and 'message' in entity['error']:
+            raise ForemanApiException(msg=entity['error']['message'])
+
+    def validate_payload(self, resource: str, action: str, payload: dict) -> Tuple[dict, Set[str]]:
+        """
+        Check whether the payload only contains supported keys.
+
+        :param resource: Plural name of the api resource to check
+        :param action: Name of the action to check payload against
+        :param payload: API paylod to be checked
+
+        :return: The payload as it can be submitted to the API and set of unssuported parameters
+        """
+        filtered_payload = self._resource_prepare_params(resource, action, payload)
+        unsupported_parameters = set(payload.keys()) - _recursive_dict_keys(filtered_payload)
+        return (filtered_payload, unsupported_parameters)
+
+
+def _recursive_dict_keys(a_dict: dict) -> set:
+    """Find all keys of a nested dictionary"""
+    keys = set(a_dict.keys())
+    for value in a_dict.values():
+        if isinstance(value, dict):
+            keys.update(_recursive_dict_keys(value))
+    return keys

docs/api.rst

@@ -6,6 +6,8 @@ Developer Interface
 .. module:: apypie
 .. autoclass:: Api
    :inherited-members:
+.. autoclass:: ForemanApi
+   :inherited-members:
 .. autoclass:: Resource
    :inherited-members:
 .. autoclass:: Action