blob: 920b56313e789b73c5955bd4b19d5b58ddb3f99b [file] [log] [blame]
# Copyright 2016 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import abc
import copy
import json
import logging
import common
from autotest_lib.server.cros import provision
class HostInfo(object):
"""Holds label/attribute information about a host as understood by infra.
This class is the source of truth of label / attribute information about a
host for the test runner (autoserv) and the tests, *from the point of view
of the infrastructure*.
Typical usage:
store = AfeHostInfoStore(...)
host_info = store.get()
update_somehow(host_info)
store.commit(host_info)
Besides the @property listed below, the following rw variables are part of
the public API:
labels: The list of labels for this host.
attributes: The list of attributes for this host.
"""
__slots__ = ['labels', 'attributes']
# Constants related to exposing labels as more semantic properties.
_BOARD_PREFIX = 'board'
_MODEL_PREFIX = 'model'
_OS_PREFIX = 'os'
_POOL_PREFIX = 'pool'
_VERSION_LABELS = (
provision.CROS_VERSION_PREFIX,
provision.CROS_ANDROID_VERSION_PREFIX,
)
def __init__(self, labels=None, attributes=None):
"""
@param labels: (optional list) labels to set on the HostInfo.
@param attributes: (optional dict) attributes to set on the HostInfo.
"""
self.labels = labels if labels is not None else []
self.attributes = attributes if attributes is not None else {}
@property
def build(self):
"""Retrieve the current build for the host.
TODO(pprabhu) Make provision.py depend on this instead of the other way
around.
@returns The first build label for this host (if there are multiple).
None if no build label is found.
"""
for label_prefix in self._VERSION_LABELS:
build_labels = self._get_stripped_labels_with_prefix(label_prefix)
if build_labels:
return build_labels[0]
return None
@property
def board(self):
"""Retrieve the board label value for the host.
@returns: The (stripped) board label, or the empty string if no
label is found.
"""
return self.get_label_value(self._BOARD_PREFIX)
@property
def model(self):
"""Retrieve the model label value for the host.
@returns: The (stripped) model label, or the empty string if no
label is found.
"""
return self.get_label_value(self._MODEL_PREFIX)
@property
def os(self):
"""Retrieve the os for the host.
@returns The os (str) or the empty string if no os label
exists. Returns the first matching os if mutiple labels
are found.
"""
return self.get_label_value(self._OS_PREFIX)
@property
def pools(self):
"""Retrieve the set of pools for the host.
@returns: set(str) of pool values.
"""
return set(self._get_stripped_labels_with_prefix(self._POOL_PREFIX))
def get_label_value(self, prefix):
"""Retrieve the value stored as a label with a well known prefix.
@param prefix: The prefix of the desired label.
@return: For the first label matching 'prefix:value', returns value.
Returns '' if no label matches the given prefix.
"""
values = self._get_stripped_labels_with_prefix(prefix)
return values[0] if values else ''
def clear_version_labels(self, version_prefix=None):
"""Clear all or a particular version label(s) for the host.
@param version_prefix: The prefix label which needs to be cleared.
If this is set to None, all version labels will
be cleared.
"""
version_labels = ([version_prefix] if version_prefix else
self._VERSION_LABELS)
self.labels = [
label for label in self.labels if
not any(label.startswith(prefix + ':')
for prefix in version_labels)]
def set_version_label(self, version_prefix, version):
"""Sets the version label for the host.
If a label with version_prefix exists, this updates the value for that
label, else appends a new label to the end of the label list.
@param version_prefix: The prefix to use (without the infix ':').
@param version: The version label value to set.
"""
full_prefix = _to_label_prefix(version_prefix)
new_version_label = full_prefix + version
for index, label in enumerate(self.labels):
if label.startswith(full_prefix):
self.labels[index] = new_version_label
return
else:
self.labels.append(new_version_label)
def _get_stripped_labels_with_prefix(self, prefix):
"""Search for labels with the prefix and remove the prefix.
e.g.
prefix = blah
labels = ['blah:a', 'blahb', 'blah:c', 'doo']
returns: ['a', 'c']
@returns: A list of stripped labels. [] in case of no match.
"""
full_prefix = prefix + ':'
prefix_len = len(full_prefix)
return [label[prefix_len:] for label in self.labels
if label.startswith(full_prefix)]
def __str__(self):
return ('%s[Labels: %s, Attributes: %s]'
% (type(self).__name__, self.labels, self.attributes))
def __eq__(self, other):
if isinstance(other, type(self)):
return (self.labels == other.labels
and self.attributes == other.attributes)
else:
return NotImplemented
def __ne__(self, other):
return not (self == other)
class StoreError(Exception):
"""Raised when a CachingHostInfoStore operation fails."""
class CachingHostInfoStore(object):
"""Abstract class to obtain and update host information from the infra.
This class describes the API used to retrieve host information from the
infrastructure. The actual, uncached implementation to obtain / update host
information is delegated to the concrete store classes.
We use two concrete stores:
AfeHostInfoStore: Directly obtains/updates the host information from
the AFE.
LocalHostInfoStore: Obtains/updates the host information from a local
file.
An extra store is provided for unittests:
InMemoryHostInfoStore: Just store labels / attributes in-memory.
"""
__metaclass__ = abc.ABCMeta
def __init__(self):
self._private_cached_info = None
def get(self, force_refresh=False):
"""Obtain (possibly cached) host information.
@param force_refresh: If True, forces the cached HostInfo to be
refreshed from the store.
@returns: A HostInfo object.
"""
if force_refresh:
return self._get_uncached()
# |_cached_info| access is costly, so do it only once.
info = self._cached_info
if info is None:
return self._get_uncached()
return info
def commit(self, info):
"""Update host information in the infrastructure.
@param info: A HostInfo object with the new information to set. You
should obtain a HostInfo object using the |get| or
|get_uncached| methods, update it as needed and then commit.
"""
logging.debug('Committing HostInfo to store %s', self)
try:
self._commit_impl(info)
self._cached_info = info
logging.debug('HostInfo updated to: %s', info)
except Exception:
self._cached_info = None
raise
@abc.abstractmethod
def _refresh_impl(self):
"""Actual implementation to refresh host_info from the store.
Concrete stores must implement this function.
@returns: A HostInfo object.
"""
raise NotImplementedError
@abc.abstractmethod
def _commit_impl(self, host_info):
"""Actual implementation to commit host_info to the store.
Concrete stores must implement this function.
@param host_info: A HostInfo object.
"""
raise NotImplementedError
def _get_uncached(self):
"""Obtain freshly synced host information.
@returns: A HostInfo object.
"""
logging.debug('Refreshing HostInfo using store %s', self)
logging.debug('Old host_info: %s', self._cached_info)
try:
info = self._refresh_impl()
self._cached_info = info
except Exception:
self._cached_info = None
raise
logging.debug('New host_info: %s', info)
return info
@property
def _cached_info(self):
"""Access the cached info, enforcing a deepcopy."""
return copy.deepcopy(self._private_cached_info)
@_cached_info.setter
def _cached_info(self, info):
"""Update the cached info, enforcing a deepcopy.
@param info: The new info to update from.
"""
self._private_cached_info = copy.deepcopy(info)
class InMemoryHostInfoStore(CachingHostInfoStore):
"""A simple store that gives unittests direct access to backing data.
Unittests can access the |info| attribute to obtain the backing HostInfo.
"""
def __init__(self, info=None):
"""Seed object with initial data.
@param info: Initial backing HostInfo object.
"""
super(InMemoryHostInfoStore, self).__init__()
self.info = info if info is not None else HostInfo()
def __str__(self):
return '%s[%s]' % (type(self).__name__, self.info)
def _refresh_impl(self):
"""Return a copy of the private HostInfo."""
return copy.deepcopy(self.info)
def _commit_impl(self, info):
"""Copy HostInfo data to in-memory store.
@param info: The HostInfo object to commit.
"""
self.info = copy.deepcopy(info)
def get_store_from_machine(machine):
"""Obtain the host_info_store object stuffed in the machine dict.
The machine argument to jobs can be a string (a hostname) or a dict because
of legacy reasons. If we can't get a real store, return a dummy.
"""
if isinstance(machine, dict):
return machine['host_info_store']
else:
return InMemoryHostInfoStore()
class DeserializationError(Exception):
"""Raised when deserialization fails due to malformed input."""
# Default serialzation version. This should be uprevved whenever a change to
# HostInfo is backwards incompatible, i.e. we can no longer correctly
# deserialize a previously serialized HostInfo. An example of such change is if
# a field in the HostInfo object is dropped.
_CURRENT_SERIALIZATION_VERSION = 1
def json_serialize(info, file_obj, version=_CURRENT_SERIALIZATION_VERSION):
"""Serialize the given HostInfo.
@param info: A HostInfo object to serialize.
@param file_obj: A file like object to serialize info into.
@param version: Use a specific serialization version. Should mostly use the
default.
"""
info_json = {
'serializer_version': version,
'labels': info.labels,
'attributes': info.attributes,
}
return json.dump(info_json, file_obj, sort_keys=True, indent=4,
separators=(',', ': '))
def json_deserialize(file_obj):
"""Deserialize a HostInfo from the given file.
@param file_obj: a file like object containing a json_serialized()ed
HostInfo.
@returns: The deserialized HostInfo object.
"""
try:
deserialized_json = json.load(file_obj)
except ValueError as e:
raise DeserializationError(e)
serializer_version = deserialized_json.get('serializer_version')
if serializer_version != 1:
raise DeserializationError('Unsupported serialization version %s' %
serializer_version)
try:
return HostInfo(deserialized_json['labels'],
deserialized_json['attributes'])
except KeyError as e:
raise DeserializationError('Malformed serialized host_info: %r' % e)
def _to_label_prefix(prefix):
"""Ensure that prefix has the expected format for label prefixes.
@param prefix: The (str) prefix to sanitize.
@returns: The sanitized (str) prefix.
"""
return prefix if prefix.endswith(':') else prefix + ':'