#!/usr/bin/env python
+# Copyright (C) The Arvados Authors. All rights reserved.
+#
+# SPDX-License-Identifier: AGPL-3.0
from __future__ import absolute_import, print_function
import libcloud.common.types as cloud_types
from libcloud.compute.base import NodeDriver, NodeAuthSSHKey
-from ...config import NETWORK_ERRORS
+from ...config import CLOUD_ERRORS
from .. import RetryMixin
class BaseComputeNodeDriver(RetryMixin):
Subclasses must implement arvados_create_kwargs, sync_node,
node_fqdn, and node_start_time.
"""
- CLOUD_ERRORS = NETWORK_ERRORS + (cloud_types.LibcloudError,)
+
@RetryMixin._retry()
def _create_driver(self, driver_class, **auth_kwargs):
key = NodeAuthSSHKey(ssh_file.read())
return 'auth', key
- def search_for(self, term, list_method, key=attrgetter('id'), **kwargs):
+ def search_for_now(self, term, list_method, key=attrgetter('id'), **kwargs):
"""Return one matching item from a list of cloud objects.
Raises ValueError if the number of matching objects is not exactly 1.
Arguments:
* term: The value that identifies a matching item.
- * list_method: A string that names the method to call on this
- instance's libcloud driver for a list of objects.
+ * list_method: A string that names the method to call for a
+ list of objects.
* key: A function that accepts a cloud object and returns a
value search for a `term` match on each item. Returns the
object's 'id' attribute by default.
"""
+ try:
+ list_func = getattr(self, list_method)
+ except AttributeError:
+ list_func = getattr(self.real, list_method)
+ items = list_func(**kwargs)
+ results = [item for item in items if key(item) == term]
+ count = len(results)
+ if count != 1:
+ raise ValueError("{} returned {} results for {!r}".format(
+ list_method, count, term))
+ return results[0]
+
+ def search_for(self, term, list_method, key=attrgetter('id'), **kwargs):
+ """Return one cached matching item from a list of cloud objects.
+
+ See search_for_now() for details of arguments and exceptions.
+ This method caches results, so it's good to find static cloud objects
+ like node sizes, regions, etc.
+ """
cache_key = (list_method, term)
if cache_key not in self.SEARCH_CACHE:
- items = getattr(self.real, list_method)(**kwargs)
- results = [item for item in items
- if key(item) == term]
- count = len(results)
- if count != 1:
- raise ValueError("{} returned {} results for '{}'".format(
- list_method, count, term))
- self.SEARCH_CACHE[cache_key] = results[0]
+ self.SEARCH_CACHE[cache_key] = self.search_for_now(
+ term, list_method, key, **kwargs)
return self.SEARCH_CACHE[cache_key]
- def list_nodes(self):
- return self.real.list_nodes(**self.list_kwargs)
+ def list_nodes(self, **kwargs):
+ l = self.list_kwargs.copy()
+ l.update(kwargs)
+ return self.real.list_nodes(**l)
+
+ def create_cloud_name(self, arvados_node):
+ """Return a cloud node name for the given Arvados node record.
+
+ Subclasses must override this method. It should return a string
+ that can be used as the name for a newly-created cloud node,
+ based on identifying information in the Arvados node record.
+
+ Arguments:
+ * arvados_node: This Arvados node record to seed the new cloud node.
+ """
+ raise NotImplementedError("BaseComputeNodeDriver.create_cloud_name")
def arvados_create_kwargs(self, size, arvados_node):
"""Return dynamic keyword arguments for create_node.
kwargs.update(self.arvados_create_kwargs(size, arvados_node))
kwargs['size'] = size
return self.real.create_node(**kwargs)
- except self.CLOUD_ERRORS:
+ except CLOUD_ERRORS as create_error:
# Workaround for bug #6702: sometimes the create node request
# succeeds but times out and raises an exception instead of
# returning a result. If this happens, we get stuck in a retry
# loop forever because subsequent create_node attempts will fail
# due to node name collision. So check if the node we intended to
# create shows up in the cloud node list and return it if found.
- node = self.search_for(kwargs['name'], 'list_nodes', self._name_key)
- if node:
- return node
- else:
- # something else went wrong, re-raise the exception
- raise
+ try:
+ return self.search_for_now(kwargs['name'], 'list_nodes', self._name_key)
+ except ValueError:
+ raise create_error
def post_create_node(self, cloud_node):
# ComputeNodeSetupActor calls this method after the cloud node is
# seconds since the epoch UTC.
raise NotImplementedError("BaseComputeNodeDriver.node_start_time")
- @classmethod
- def is_cloud_exception(cls, exception):
- # libcloud compute drivers typically raise bare Exceptions to
- # represent API errors. Return True for any exception that is
- # exactly an Exception, or a better-known higher-level exception.
- return (isinstance(exception, cls.CLOUD_ERRORS) or
- type(exception) is Exception)
+ def destroy_node(self, cloud_node):
+ try:
+ return self.real.destroy_node(cloud_node)
+ except CLOUD_ERRORS as destroy_error:
+ # Sometimes the destroy node request succeeds but times out and
+ # raises an exception instead of returning success. If this
+ # happens, we get a noisy stack trace. Check if the node is still
+ # on the node list. If it is gone, we can declare victory.
+ try:
+ self.search_for_now(cloud_node.id, 'list_nodes')
+ except ValueError:
+ # If we catch ValueError, that means search_for_now didn't find
+ # it, which means destroy_node actually succeeded.
+ return True
+ # The node is still on the list. Re-raise.
+ raise
# Now that we've defined all our own methods, delegate generic, public
# attributes of libcloud drivers that we haven't defined ourselves.