X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/0d63ac0c2486a43198eb1015ba8d1028239139ee..d5341150545efd0960acf34186ca18b98a1b1860:/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 369bb8f953..16134a2844 100644 --- a/services/nodemanager/arvnodeman/computenode/driver/__init__.py +++ b/services/nodemanager/arvnodeman/computenode/driver/__init__.py @@ -2,30 +2,52 @@ from __future__ import absolute_import, print_function +from operator import attrgetter + import libcloud.common.types as cloud_types from libcloud.compute.base import NodeDriver from ...config import NETWORK_ERRORS +import pprint + class BaseComputeNodeDriver(object): """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): + """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. + """ self.real = driver_class(**auth_kwargs) self.list_kwargs = list_kwargs self.create_kwargs = create_kwargs + # 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: @@ -36,10 +58,23 @@ class BaseComputeNodeDriver(object): def _init_ping_host(self, ping_host): self.ping_host = ping_host - def search_for(self, term, list_method, key=lambda item: item.id): + def search_for(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. + """ cache_key = (list_method, term) if cache_key not in self.SEARCH_CACHE: - results = [item for item in getattr(self.real, list_method)() + items = getattr(self.real, list_method)(**kwargs) + results = [item for item in items if key(item) == term] count = len(results) if count != 1: @@ -52,6 +87,17 @@ class BaseComputeNodeDriver(object): return self.real.list_nodes(**self.list_kwargs) def arvados_create_kwargs(self, 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: + * 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 _make_ping_url(self, arvados_node): @@ -78,8 +124,16 @@ 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 @@ -88,7 +142,7 @@ 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.