def __init__(self, session_vars=None, event_hooks=None,
include_builtin_handlers=True, loader=None):
"""
Create a new Session object.
:type session_vars: dict
:param session_vars: A dictionary that is used to override some or all
of the environment variables associated with this session. The
key/value pairs defined in this dictionary will override the
corresponding variables defined in ``SessionVariables``.
:type event_hooks: BaseEventHooks
:param event_hooks: The event hooks object to use. If one is not
provided, an event hooks object will be automatically created
for you.
:type include_builtin_handlers: bool
:param include_builtin_handlers: Indicates whether or not to
automatically register builtin handlers.
"""
self.session_var_map = copy.copy(self.SessionVariables)
if session_vars:
self.session_var_map.update(session_vars)
if event_hooks is None:
self._events = HierarchicalEmitter()
else:
self._events = event_hooks
if include_builtin_handlers:
self._register_builtin_handlers(self._events)
self.user_agent_name = 'Botocore'
self.user_agent_version = __version__
self.user_agent_extra = ''
self._profile = None
self._config = None
self._credentials = None
self._profile_map = None
self._provider = None
# This is a dict that stores per session specific config variable
# overrides via set_config_variable().
self._session_instance_vars = {}
if loader is None:
loader = Loader()
self._loader = loader
# _data_paths_added is used to track whether or not we added
# extra paths to the loader. We will do this lazily
# only when we ask for the loader.
self._data_paths_added = False
self._components = ComponentLocator()
self._register_components()
class Session(object):
"""
The Session object collects together useful functionality
from `botocore` as well as important data such as configuration
information and credentials into a single, easy-to-use object.
:ivar available_profiles: A list of profiles defined in the config
file associated with this session.
:ivar profile: The current profile.
"""
AllEvents = {
'after-call': '.%s.%s',
'after-parsed': '.%s.%s.%s.%s',
'before-parameter-build': '.%s.%s',
'before-call': '.%s.%s',
'service-created': '',
'service-data-loaded': '.%s',
'creating-endpoint': '.%s',
'before-auth': '.%s',
'needs-retry': '.%s.%s',
}
"""
A dictionary where each key is an event name and the value
is the formatting string used to construct a new event.
"""
SessionVariables = {
# logical: config_file, env_var, default_value
'profile': (None, 'BOTO_DEFAULT_PROFILE', None),
'region': ('region', 'BOTO_DEFAULT_REGION', None),
'data_path': ('data_path', 'BOTO_DATA_PATH', None),
'config_file': (None, 'AWS_CONFIG_FILE', '~/.aws/config'),
'provider': ('provider', 'BOTO_PROVIDER_NAME', 'aws'),
# These variables are intended for internal use so don't have any
# user settable values.
# This is the shared credentials file amongst sdks.
'credentials_file': (None, None, '~/.aws/credentials'),
# These variables only exist in the config file.
# This is the number of seconds until we time out a request to
# the instance metadata service.
'metadata_service_timeout': ('metadata_service_timeout', None, 1),
# This is the number of request attempts we make until we give
# up trying to retrieve data from the instance metadata service.
'metadata_service_num_attempts': ('metadata_service_num_attempts',
None, 1),
}
"""
A default dictionary that maps the logical names for session variables
to the specific environment variables and configuration file names
that contain the values for these variables.
When creating a new Session object, you can pass in your own dictionary to
remap the logical names or to add new logical names. You can then get the
current value for these variables by using the ``get_config_variable``
method of the :class:`botocore.session.Session` class.
The default set of logical variable names are:
* profile - Default profile name you want to use.
* region - Default region name to use, if not otherwise specified.
* data_path - Additional directories to search for data files.
* config_file - Location of a Boto config file.
* provider - The name of the service provider (e.g. aws)
These form the keys of the dictionary. The values in the dictionary
are tuples of (<config_name>, <environment variable>, <default value).
The ``profile`` and ``config_file`` variables should always have a
None value for the first entry in the tuple because it doesn't make
sense to look inside the config file for the location of the config
file or for the default profile to use.
The ``config_name`` is the name to look for in the configuration file,
the ``env var`` is the OS environment variable (``os.environ``) to
use, and ``default_value`` is the value to use if no value is otherwise
found.
"""
FmtString = '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
def __init__(self, session_vars=None, event_hooks=None,
include_builtin_handlers=True, loader=None):
"""
Create a new Session object.
:type session_vars: dict
:param session_vars: A dictionary that is used to override some or all
of the environment variables associated with this session. The
key/value pairs defined in this dictionary will override the
corresponding variables defined in ``SessionVariables``.
:type event_hooks: BaseEventHooks
:param event_hooks: The event hooks object to use. If one is not
provided, an event hooks object will be automatically created
for you.
:type include_builtin_handlers: bool
:param include_builtin_handlers: Indicates whether or not to
automatically register builtin handlers.
"""
self.session_var_map = copy.copy(self.SessionVariables)
if session_vars:
self.session_var_map.update(session_vars)
if event_hooks is None:
self._events = HierarchicalEmitter()
else:
self._events = event_hooks
if include_builtin_handlers:
self._register_builtin_handlers(self._events)
self.user_agent_name = 'Botocore'
self.user_agent_version = __version__
self.user_agent_extra = ''
self._profile = None
self._config = None
self._credentials = None
self._profile_map = None
self._provider = None
# This is a dict that stores per session specific config variable
# overrides via set_config_variable().
self._session_instance_vars = {}
if loader is None:
loader = Loader()
self._loader = loader
# _data_paths_added is used to track whether or not we added
# extra paths to the loader. We will do this lazily
# only when we ask for the loader.
self._data_paths_added = False
self._components = ComponentLocator()
self._register_components()
def _register_components(self):
self._register_credential_provider()
self._register_data_loader()
self._register_endpoint_resolver()
self._register_event_emitter()
def _register_event_emitter(self):
self._components.register_component('event_emitter', self._events)
def _register_credential_provider(self):
self._components.lazy_register_component(
'credential_provider',
lambda: botocore_eb.credentials.create_credential_resolver(self))
def _register_data_loader(self):
self._components.lazy_register_component(
'data_loader',
lambda: Loader(self.get_config_variable('data_path') or ''))
def _register_endpoint_resolver(self):
self._components.lazy_register_component(
'endpoint_resolver',
lambda: regions.EndpointResolver(self.get_data('aws/_endpoints')))
def _reset_components(self):
self._register_components()
def _register_builtin_handlers(self, events):
for event_name, handler in handlers.BUILTIN_HANDLERS:
self.register(event_name, handler)
@property
def provider(self):
if self._provider is None:
self._provider = get_provider(
self, self.get_config_variable('provider'))
return self._provider
@property
def available_profiles(self):
return list(self._build_profile_map().keys())
def _build_profile_map(self):
# This will build the profile map if it has not been created,
# otherwise it will return the cached value. The profile map
# is a list of profile names, to the config values for the profile.
if self._profile_map is None:
self._profile_map = self.full_config['profiles']
return self._profile_map
@property
def profile(self):
return self._profile
@profile.setter
def profile(self, profile):
# Since provider can be specified in profile, changing the
# profile should reset the provider.
self._provider = None
self._profile = profile
# Need to potentially reload the config file/creds.
self._reset_components()
def get_config_variable(self, logical_name,
methods=('instance', 'env', 'config'),
default=None):
"""
Retrieve the value associated with the specified logical_name
from the environment or the config file. Values found in the
environment variable take precedence of values found in the
config file. If no value can be found, a None will be returned.
:type logical_name: str
:param logical_name: The logical name of the session variable
you want to retrieve. This name will be mapped to the
appropriate environment variable name for this session as
well as the appropriate config file entry.
:type method: tuple
:param method: Defines which methods will be used to find
the variable value. By default, all available methods
are tried but you can limit which methods are used
by supplying a different value to this parameter.
Valid choices are: instance|env|config
:param default: The default value to return if there is no
value associated with the config file. This value will
override any default value specified in ``SessionVariables``.
:returns: str value of variable of None if not defined.
"""
value = None
# There's two types of defaults here. One if the
# default value specified in the SessionVariables.
# The second is an explicit default value passed into this
# function (the default parameter).
# config_default is tracking the default value specified
# in the SessionVariables.
config_default = None
if logical_name in self.session_var_map:
# Short circuit case, check if the var has been explicitly
# overriden via set_config_variable.
if 'instance' in methods and \
logical_name in self._session_instance_vars:
return self._session_instance_vars[logical_name]
config_name, envvar_name, config_default = self.session_var_map[
logical_name]
if logical_name in ('config_file', 'profile'):
config_name = None
if logical_name == 'profile' and self._profile:
value = self._profile
elif 'env' in methods and envvar_name and envvar_name in os.environ:
value = os.environ[envvar_name]
elif 'config' in methods:
if config_name:
config = self.get_scoped_config()
value = config.get(config_name)
# If we don't have a value at this point, we need to try to assign
# a default value. An explicit default argument will win over the
# default value from SessionVariables.
if value is None and default is not None:
value = default
if value is None and config_default is not None:
value = config_default
return value
def set_config_variable(self, logical_name, value):
"""Set a configuration variable to a specific value.
By using this method, you can override the normal lookup
process used in ``get_config_variable`` by explicitly setting
a value. Subsequent calls to ``get_config_variable`` will
use the ``value``. This gives you per-session specific
configuration values.
::
>>> # Assume logical name 'foo' maps to env var 'FOO'
>>> os.environ['FOO'] = 'myvalue'
>>> s.get_config_variable('foo')
'myvalue'
>>> s.set_config_variable('foo', 'othervalue')
>>> s.get_config_variable('foo')
'othervalue'
:type logical_name: str
:param logical_name: The logical name of the session variable
you want to set. These are the keys in ``SessionVariables``.
:param value: The value to associate with the config variable.
"""
self._session_instance_vars[logical_name] = value
def get_scoped_config(self):
"""
Returns the config values from the config file scoped to the current
profile.
The configuration data is loaded **only** from the config file.
It does not resolve variables based on different locations
(e.g. first from the session instance, then from environment
variables, then from the config file). If you want this lookup
behavior, use the ``get_config_variable`` method instead.
Note that this configuration is specific to a single profile (the
``profile`` session variable).
If the ``profile`` session variable is set and the profile does
not exist in the config file, a ``ProfileNotFound`` exception
will be raised.
:raises: ConfigNotFound, ConfigParseError, ProfileNotFound
:rtype: dict
"""
profile_name = self.get_config_variable('profile')
profile_map = self._build_profile_map()
# If a profile is not explicitly set return the default
# profile config or an empty config dict if we don't have
# a default profile.
if profile_name is None:
return profile_map.get('default', {})
elif profile_name not in profile_map:
# Otherwise if they specified a profile, it has to
# exist (even if it's the default profile) otherwise
# we complain.
raise ProfileNotFound(profile=profile_name)
else:
return profile_map[profile_name]
@property
def full_config(self):
"""Return the parsed config file.
The ``get_config`` method returns the config associated with the
specified profile. This property returns the contents of the
**entire** config file.
:rtype: dict
"""
if self._config is None:
try:
config_file = self.get_config_variable('config_file')
self._config = botocore_eb.config.load_config(config_file)
except ConfigNotFound:
self._config = {'profiles': {}}
try:
# Now we need to inject the profiles from the
# credentials file. We don't actually need the values
# in the creds file, only the profile names so that we
# can validate the user is not referring to a nonexistent
# profile.
cred_file = self.get_config_variable('credentials_file')
cred_profiles = botocore_eb.config.raw_config_parse(cred_file)
for profile in cred_profiles:
cred_vars = cred_profiles[profile]
if profile not in self._config['profiles']:
self._config['profiles'][profile] = cred_vars
else:
self._config['profiles'][profile].update(cred_vars)
except ConfigNotFound:
pass
return self._config
def set_credentials(self, access_key, secret_key, token=None):
"""
Manually create credentials for this session. If you would
prefer to use botocore without a config file, environment variables,
or IAM roles, you can pass explicit credentials into this
method to establish credentials for this session.
:type access_key: str
:param access_key: The access key part of the credentials.
:type secret_key: str
:param secret_key: The secret key part of the credentials.
:type token: str
:param token: An option session token used by STS session
credentials.
"""
self._credentials = botocore_eb.credentials.Credentials(access_key,
secret_key,
token)
def get_credentials(self):
"""
Return the :class:`botocore.credential.Credential` object
associated with this session. If the credentials have not
yet been loaded, this will attempt to load them. If they
have already been loaded, this will return the cached
credentials.
"""
if self._credentials is None:
self._credentials = self._components.get_component(
'credential_provider').load_credentials()
return self._credentials
def user_agent(self):
"""
Return a string suitable for use as a User-Agent header.
The string will be of the form:
<agent_name>/<agent_version> Python/<py_ver> <plat_name>/<plat_ver>
Where:
- agent_name is the value of the `user_agent_name` attribute
of the session object (`Boto` by default).
- agent_version is the value of the `user_agent_version`
attribute of the session object (the botocore version by default).
by default.
- py_ver is the version of the Python interpreter beng used.
- plat_name is the name of the platform (e.g. Darwin)
- plat_ver is the version of the platform
If ``user_agent_extra`` is not empty, then this value will be
appended to the end of the user agent string.
"""
base = '%s/%s Python/%s %s/%s' % (self.user_agent_name,
self.user_agent_version,
platform.python_version(),
platform.system(),
platform.release())
if self.user_agent_extra:
base += ' %s' % self.user_agent_extra
return base
def get_data(self, data_path):
"""
Retrieve the data associated with `data_path`.
:type data_path: str
:param data_path: The path to the data you wish to retrieve.
"""
return self.get_component('data_loader').load_data(data_path)
def get_service_model(self, service_name, api_version=None):
"""Get the service model object.
:type service_name: string
:param service_name: The service name
:type api_version: string
:param api_version: The API version of the service. If none is
provided, then the latest API version will be used.
:rtype: L{botocore.model.ServiceModel}
:return: The botocore service model for the service.
"""
service_description = self.get_service_data(service_name, api_version)
return ServiceModel(service_description)
def get_service_data(self, service_name, api_version=None):
"""
Retrieve the fully merged data associated with a service.
"""
data_path = '%s/%s' % (self.provider.name, service_name)
service_data = self.get_component('data_loader').load_service_model(
data_path,
api_version=api_version
)
event_name = self.create_event('service-data-loaded', service_name)
self._events.emit(event_name, service_data=service_data,
service_name=service_name, session=self)
return service_data
def get_available_services(self):
"""
Return a list of names of available services.
"""
data_path = '%s' % self.provider.name
return self.get_component('data_loader')\
.list_available_services(data_path)
def get_service(self, service_name, api_version=None):
"""
Get information about a service.
:type service_name: str
:param service_name: The name of the service (e.g. 'ec2')
:returns: :class:`botocore_eb.service.Service`
"""
service = botocore_eb.service.get_service(self, service_name,
self.provider,
api_version=api_version)
event = self.create_event('service-created')
self._events.emit(event, service=service)
return service
def set_debug_logger(self, logger_name='botocore'):
"""
Convenience function to quickly configure full debug output
to go to the console.
"""
self.set_stream_logger(logger_name, logging.DEBUG)
def set_stream_logger(self, logger_name, log_level, stream=None,
format_string=None):
"""
Convenience method to configure a stream logger.
:type logger_name: str
:param logger_name: The name of the logger to configure
:type log_level: str
:param log_level: The log level to set for the logger. This
is any param supported by the ``.setLevel()`` method of
a ``Log`` object.
:type stream: file
:param stream: A file like object to log to. If none is provided
then sys.stderr will be used.
:type format_string: str
:param format_string: The format string to use for the log
formatter. If none is provided this will default to
``self.FmtString``.
"""
log = logging.getLogger(logger_name)
log.setLevel(logging.DEBUG)
ch = logging.StreamHandler(stream)
ch.setLevel(log_level)
# create formatter
if format_string is None:
format_string = self.FmtString
formatter = logging.Formatter(format_string)
# add formatter to ch
ch.setFormatter(formatter)
# add ch to logger
log.addHandler(ch)
def set_file_logger(self, log_level, path, logger_name='botocore'):
"""
Convenience function to quickly configure any level of logging
to a file.
:type log_level: int
:param log_level: A log level as specified in the `logging` module
:type path: string
:param path: Path to the log file. The file will be created
if it doesn't already exist.
"""
log = logging.getLogger(logger_name)
log.setLevel(logging.DEBUG)
# create console handler and set level to debug
ch = logging.FileHandler(path)
ch.setLevel(log_level)
# create formatter
formatter = logging.Formatter(self.FmtString)
# add formatter to ch
ch.setFormatter(formatter)
# add ch to logger
log.addHandler(ch)
def register(self, event_name, handler, unique_id=None,
unique_id_uses_count=False):
"""Register a handler with an event.
:type event_name: str
:param event_name: The name of the event.
:type handler: callable
:param handler: The callback to invoke when the event
is emitted. This object must be callable, and must
accept ``**kwargs``. If either of these preconditions are
not met, a ``ValueError`` will be raised.
:type unique_id: str
:param unique_id: An optional identifier to associate with the
registration. A unique_id can only be used once for
the entire session registration (unless it is unregistered).
This can be used to prevent an event handler from being
registered twice.
:param unique_id_uses_count: boolean
:param unique_id_uses_count: Specifies if the event should maintain
a count when a ``unique_id`` is registered and unregisted. The
event can only be completely unregistered once every register call
using the unique id has been matched by an ``unregister`` call.
If ``unique_id`` is specified, subsequent ``register``
calls must use the same value for ``unique_id_uses_count``
as the ``register`` call that first registered the event.
:raises ValueError: If the call to ``register`` uses ``unique_id``
but the value for ``unique_id_uses_count`` differs from the
``unique_id_uses_count`` value declared by the very first
``register`` call for that ``unique_id``.
"""
self._events.register(event_name, handler, unique_id,
unique_id_uses_count=unique_id_uses_count)
def unregister(self, event_name, handler=None, unique_id=None,
unique_id_uses_count=False):
"""Unregister a handler with an event.
:type event_name: str
:param event_name: The name of the event.
:type handler: callable
:param handler: The callback to unregister.
:type unique_id: str
:param unique_id: A unique identifier identifying the callback
to unregister. You can provide either the handler or the
unique_id, you do not have to provide both.
:param unique_id_uses_count: boolean
:param unique_id_uses_count: Specifies if the event should maintain
a count when a ``unique_id`` is registered and unregisted. The
event can only be completely unregistered once every ``register``
call using the ``unique_id`` has been matched by an ``unregister``
call. If the ``unique_id`` is specified, subsequent
``unregister`` calls must use the same value for
``unique_id_uses_count`` as the ``register`` call that first
registered the event.
:raises ValueError: If the call to ``unregister`` uses ``unique_id``
but the value for ``unique_id_uses_count`` differs from the
``unique_id_uses_count`` value declared by the very first
``register`` call for that ``unique_id``.
"""
self._events.unregister(event_name, handler=handler,
unique_id=unique_id,
unique_id_uses_count=unique_id_uses_count)
def register_event(self, event_name, fmtstr):
"""
Register a new event. The event will be added to ``AllEvents``
and will then be able to be created using ``create_event``.
:type event_name: str
:param event_name: The base name of the event.
:type fmtstr: str
:param fmtstr: The formatting string for the event.
"""
if event_name not in self.AllEvents:
self.AllEvents[event_name] = fmtstr
def create_event(self, event_name, *fmtargs):
"""
Creates a new event string that can then be emitted.
You could just create it manually, since it's just
a string but this helps to define the range of known events.
:type event_name: str
:param event_name: The base name of the new event.
:type fmtargs: tuple
:param fmtargs: A tuple of values that will be used as the
arguments pass to the string formatting operation. The
actual values passed depend on the type of event you
are creating.
"""
if event_name in self.AllEvents:
fmt_string = self.AllEvents[event_name]
if fmt_string:
event = event_name + (fmt_string % fmtargs)
else:
event = event_name
return event
raise EventNotFound(event_name=event_name)
def emit(self, event_name, **kwargs):
return self._events.emit(event_name, **kwargs)
def emit_first_non_none_response(self, event_name, **kwargs):
responses = self._events.emit(event_name, **kwargs)
return first_non_none_response(responses)
def get_component(self, name):
return self._components.get_component(name)
def register_component(self, name, component):
self._components.register_component(name, component)
def lazy_register_component(self, name, component):
self._components.lazy_register_component(name, component)
def create_client(self, service_name, region_name=None, api_version=None,
use_ssl=True, verify=None, endpoint_url=None):
"""Create a botocore client.
:type service_name: string
:param service_name: The name of the service for which a client will
be created. You can use the ``Sesssion.get_available_services()``
method to get a list of all available service names.
:type region_name: string
:param region_name: The name of the region associated with the client.
A client is associated with a single region.
:type api_version: string
:param api_version: The API version to use. By default, botocore will
use the latest API version when creating a client. You only need
to specify this parameter if you want to use a previous API version
of the client.
:type use_ssl: boolean
:param use_ssl: Whether or not to use SSL. By default, SSL is used. Note that
not all services support non-ssl connections.
:type verify: boolean/string
:param verify: Whether or not to verify SSL certificates. By default SSL certificates
are verified. You can provide the following values:
* False - do not validate SSL certificates. SSL will still be
used (unless use_ssl is False), but SSL certificates
will not be verified.
* path/to/cert/bundle.pem - A filename of the CA cert bundle to
uses. You can specify this argument if you want to use a different
CA cert bundle than the one used by botocore.
:type endpoint_url: string
:param endpoint_url: The complete URL to use for the constructed client.
Normally, botocore will automatically construct the appropriate URL
to use when communicating with a service. You can specify a
complete URL (including the "http/https" scheme) to override this
behavior. If this value is provided, then ``use_ssl`` is ignored.
:rtype: botocore.client.BaseClient
:return: A botocore client instance
"""
loader = self.get_component('data_loader')
endpoint_creator = self._create_endpoint_creator()
client_creator = botocore_eb.client.ClientCreator(loader, endpoint_creator)
client = client_creator.create_client(service_name, region_name, use_ssl,
endpoint_url, verify)
return client
def _create_endpoint_creator(self):
resolver = self.get_component('endpoint_resolver')
region = self.get_config_variable('region')
event_emitter = self.get_component('event_emitter')
credentials = self.get_credentials()
user_agent= self.user_agent()
endpoint_creator = EndpointCreator(resolver, region, event_emitter,
credentials, user_agent)
return endpoint_creator
