X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/2bf83ac52cf6af212044ec6f0d3c77b5713bb664..refs/heads/8872-node-manager-create-search-handling-wip:/services/nodemanager/arvnodeman/computenode/driver/__init__.py diff --git a/services/nodemanager/arvnodeman/computenode/driver/__init__.py b/services/nodemanager/arvnodeman/computenode/driver/__init__.py index 3a0c2063b4..95b6fa8e0c 100644 --- a/services/nodemanager/arvnodeman/computenode/driver/__init__.py +++ b/services/nodemanager/arvnodeman/computenode/driver/__init__.py @@ -2,61 +2,179 @@ from __future__ import absolute_import, print_function +import logging +from operator import attrgetter + import libcloud.common.types as cloud_types +from libcloud.compute.base import NodeDriver, NodeAuthSSHKey from ...config import NETWORK_ERRORS +from .. import RetryMixin -class BaseComputeNodeDriver(object): +class BaseComputeNodeDriver(RetryMixin): """Abstract base class for compute node drivers. - libcloud abstracts away many of the differences between cloud providers, - but managing compute nodes requires some cloud-specific features (e.g., - on EC2 we use tags to identify compute nodes). Compute node drivers - are responsible for translating the node manager's cloud requests to a - specific cloud's vocabulary. + libcloud drivers abstract away many of the differences between + cloud providers, but managing compute nodes requires some + cloud-specific features (e.g., keeping track of node FQDNs and + boot times). Compute node drivers are responsible for translating + the node manager's cloud requests to a specific cloud's + vocabulary. - Subclasses must implement arvados_create_kwargs (to update node - creation kwargs with information about the specific Arvados node - record), sync_node, and node_start_time. + Subclasses must implement arvados_create_kwargs, sync_node, + node_fqdn, and node_start_time. """ CLOUD_ERRORS = NETWORK_ERRORS + (cloud_types.LibcloudError,) - def __init__(self, auth_kwargs, list_kwargs, create_kwargs, driver_class): - self.real = driver_class(**auth_kwargs) + @RetryMixin._retry() + def _create_driver(self, driver_class, **auth_kwargs): + return driver_class(**auth_kwargs) + + @RetryMixin._retry() + def _set_sizes(self): + self.sizes = {sz.id: sz for sz in self.real.list_sizes()} + + def __init__(self, auth_kwargs, list_kwargs, create_kwargs, + driver_class, retry_wait=1, max_retry_wait=180): + """Base initializer for compute node drivers. + + Arguments: + * auth_kwargs: A dictionary of arguments that are passed into the + driver_class constructor to instantiate a libcloud driver. + * list_kwargs: A dictionary of arguments that are passed to the + libcloud driver's list_nodes method to return the list of compute + nodes. + * create_kwargs: A dictionary of arguments that are passed to the + libcloud driver's create_node method to create a new compute node. + * driver_class: The class of a libcloud driver to use. + """ + + super(BaseComputeNodeDriver, self).__init__(retry_wait, max_retry_wait, + logging.getLogger(self.__class__.__name__), + type(self), + None) + self.real = self._create_driver(driver_class, **auth_kwargs) self.list_kwargs = list_kwargs self.create_kwargs = create_kwargs - - def __getattr__(self, name): - # Proxy non-extension methods to the real driver. - if (not name.startswith('_') and not name.startswith('ex_') - and hasattr(self.real, name)): - return getattr(self.real, name) - else: - return super(BaseComputeNodeDriver, self).__getattr__(name) - - def search_for(self, term, list_method, key=lambda item: item.id): + # Transform entries in create_kwargs. For each key K, if this class + # has an _init_K method, remove the entry and call _init_K with the + # corresponding value. If _init_K returns None, the entry stays out + # of the dictionary (we expect we're holding the value somewhere + # else, like an instance variable). Otherwise, _init_K returns a + # key-value tuple pair, and we add that entry to create_kwargs. + for key in self.create_kwargs.keys(): + init_method = getattr(self, '_init_' + key, None) + if init_method is not None: + new_pair = init_method(self.create_kwargs.pop(key)) + if new_pair is not None: + self.create_kwargs[new_pair[0]] = new_pair[1] + + self._set_sizes() + + def _init_ping_host(self, ping_host): + self.ping_host = ping_host + + def _init_ssh_key(self, filename): + with open(filename) as ssh_file: + key = NodeAuthSSHKey(ssh_file.read()) + return 'auth', key + + 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. + * 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. + """ + 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 {!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: - results = [item for item in getattr(self.real, list_method)() - 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. - def arvados_create_kwargs(self, arvados_node): + 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. + + Subclasses must override this method. It should return a dictionary + of keyword arguments to pass to the libcloud driver's create_node + method. These arguments will extend the static arguments in + create_kwargs. + + Arguments: + * size: The node size that will be created (libcloud NodeSize object) + * arvados_node: The Arvados node record that will be associated + with this cloud node, as returned from the API server. + """ raise NotImplementedError("BaseComputeNodeDriver.arvados_create_kwargs") + def broken(self, cloud_node): + """Return true if libcloud has indicated the node is in a "broken" state.""" + return False + + def _make_ping_url(self, arvados_node): + return 'https://{}/arvados/v1/nodes/{}/ping?ping_secret={}'.format( + self.ping_host, arvados_node['uuid'], + arvados_node['info']['ping_secret']) + + @staticmethod + def _name_key(cloud_object): + return cloud_object.name + def create_node(self, size, arvados_node): - kwargs = self.create_kwargs.copy() - kwargs.update(self.arvados_create_kwargs(arvados_node)) - kwargs['size'] = size - return self.real.create_node(**kwargs) + try: + kwargs = self.create_kwargs.copy() + kwargs.update(self.arvados_create_kwargs(size, arvados_node)) + kwargs['size'] = size + return self.real.create_node(**kwargs) + except self.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. + 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 @@ -71,8 +189,16 @@ class BaseComputeNodeDriver(object): # information back to the cloud node appropriately. raise NotImplementedError("BaseComputeNodeDriver.sync_node") + @classmethod + def node_fqdn(cls, node): + # This method should return the FQDN of the node object argument. + # Different clouds store this in different places. + raise NotImplementedError("BaseComputeNodeDriver.node_fqdn") + @classmethod def node_start_time(cls, node): + # This method should return the time the node was started, in + # seconds since the epoch UTC. raise NotImplementedError("BaseComputeNodeDriver.node_start_time") @classmethod @@ -81,4 +207,22 @@ class BaseComputeNodeDriver(object): # 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 - getattr(exception, '__class__', None) is Exception) + type(exception) is Exception) + + # Now that we've defined all our own methods, delegate generic, public + # attributes of libcloud drivers that we haven't defined ourselves. + def _delegate_to_real(attr_name): + return property( + lambda self: getattr(self.real, attr_name), + lambda self, value: setattr(self.real, attr_name, value), + doc=getattr(getattr(NodeDriver, attr_name), '__doc__', None)) + + # node id + @classmethod + def node_id(cls): + raise NotImplementedError("BaseComputeNodeDriver.node_id") + + _locals = locals() + for _attr_name in dir(NodeDriver): + if (not _attr_name.startswith('_')) and (_attr_name not in _locals): + _locals[_attr_name] = _delegate_to_real(_attr_name)