# Copyright 2016,2021 IBM Corp. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Session class: A session to the HMC, optionally in context of an HMC user.
"""
import json
import time
import re
from copy import copy
from collections import OrderedDict
from collections.abc import Iterable
import requests
import urllib3
from ._exceptions import HTTPError, ServerAuthError, ClientAuthError, \
ParseError, ConnectTimeout, ReadTimeout, RetriesExceeded, \
OperationTimeout, Error
from ._exceptions import ConnectionError # pylint: disable=redefined-builtin
from ._timestats import TimeStatsKeeper
from ._auto_updater import AutoUpdater
from ._logging import get_logger, logged_api_call
from ._constants import DEFAULT_CONNECT_TIMEOUT, DEFAULT_CONNECT_RETRIES, \
DEFAULT_READ_TIMEOUT, DEFAULT_READ_RETRIES, DEFAULT_MAX_REDIRECTS, \
DEFAULT_OPERATION_TIMEOUT, DEFAULT_STATUS_TIMEOUT, \
DEFAULT_NAME_URI_CACHE_TIMETOLIVE, HMC_LOGGER_NAME, \
HTML_REASON_WEB_SERVICES_DISABLED, HTML_REASON_OTHER, \
DEFAULT_HMC_PORT
from ._utils import repr_obj_id
from ._version import __version__
__all__ = ['Session', 'Job', 'RetryTimeoutConfig', 'get_password_interface']
HMC_LOGGER = get_logger(HMC_LOGGER_NAME)
_HMC_SCHEME = "https"
_STD_HEADERS = {
'User-Agent': f'python-zhmcclient/{__version__}',
'Content-type': 'application/json',
'Accept': '*/*'
}
BLANKED_OUT = '********' # Replacement for blanked out sensitive values
def _handle_request_exc(exc, retry_timeout_config):
"""
Handle a :exc:`request.exceptions.RequestException` exception that was
raised.
"""
if isinstance(exc, requests.exceptions.ConnectTimeout):
new_exc = ConnectTimeout(_request_exc_message(exc), exc,
retry_timeout_config.connect_timeout,
retry_timeout_config.connect_retries)
new_exc.__cause__ = None
raise new_exc # ConnectTimeout
if isinstance(exc, requests.exceptions.ReadTimeout):
new_exc = ReadTimeout(_request_exc_message(exc), exc,
retry_timeout_config.read_timeout,
retry_timeout_config.read_retries)
new_exc.__cause__ = None
raise new_exc # ReadTimeout
if isinstance(exc, requests.exceptions.RetryError):
new_exc = RetriesExceeded(_request_exc_message(exc), exc,
retry_timeout_config.connect_retries)
new_exc.__cause__ = None
raise new_exc # RetriesExceeded
new_exc = ConnectionError(_request_exc_message(exc), exc)
new_exc.__cause__ = None
raise new_exc # ConnectionError
def _request_exc_message(exc):
"""
Return a reasonable exception message from a
:exc:`request.exceptions.RequestException` exception.
The approach is to dig deep to the original reason, if the original
exception is present, skipping irrelevant exceptions such as
`urllib3.exceptions.MaxRetryError`, and eliminating useless object
representations such as the connection pool object in
`urllib3.exceptions.NewConnectionError`.
Parameters:
exc (:exc:`~request.exceptions.RequestException`): Exception
Returns:
string: A reasonable exception message from the specified exception.
"""
messages = []
for arg in exc.args:
if isinstance(arg, Exception):
org_exc = arg
if isinstance(org_exc, urllib3.exceptions.MaxRetryError):
message = f"{org_exc}, reason: {org_exc.reason}"
else:
message = str(org_exc)
else:
message = str(arg)
# Eliminate useless object repr at begin of the message
m = re.match(r'^(\(<[^>]+>, \'(.*)\'\)|<[^>]+>: (.*))$', message)
if m:
message = m.group(2) or m.group(3)
messages.append(message)
return ", ".join(messages)
[docs]
class RetryTimeoutConfig:
# pylint: disable=too-few-public-methods
"""
A configuration setting that specifies verious retry counts and timeout
durations.
HMC/SE version requirements: None
"""
def __init__(self, connect_timeout=None, connect_retries=None,
read_timeout=None, read_retries=None, max_redirects=None,
operation_timeout=None, status_timeout=None,
name_uri_cache_timetolive=None):
"""
For all parameters, `None` means that this object does not specify a
value for the parameter, and that a default value should be used
(see :ref:`Constants`).
All parameters are available as instance attributes.
Parameters:
connect_timeout (:term:`number`): Connect timeout in seconds.
This timeout applies to making a connection at the socket level.
The same socket connection is used for sending an HTTP request to
the HMC and for receiving its HTTP response.
The special value 0 means that no timeout is set.
connect_retries (:term:`integer`): Number of retries (after the
initial attempt) for connection-related issues. These retries are
performed for failed DNS lookups, failed socket connections, and
socket connection timeouts.
read_timeout (:term:`number`): Read timeout in seconds.
This timeout applies to reading at the socket level, when receiving
an HTTP response.
The special value 0 means that no timeout is set.
read_retries (:term:`integer`): Number of retries (after the
initial attempt) for read-related issues. These retries are
performed for failed socket reads and socket read timeouts.
A retry consists of resending the original HTTP request. The
zhmcclient restricts these retries to just the HTTP GET method.
For other HTTP methods, no retry will be performed.
max_redirects (:term:`integer`): Maximum number of HTTP redirects.
operation_timeout (:term:`number`): Asynchronous operation timeout in
seconds. This timeout applies when waiting for the completion of
asynchronous HMC operations. The special value 0 means that no
timeout is set.
status_timeout (:term:`number`): Resource status timeout in seconds.
This timeout applies when waiting for the transition of the status
of a resource to a desired status. The special value 0 means that
no timeout is set.
name_uri_cache_timetolive (:term:`number`): Time to the next
automatic invalidation of the Name-URI cache of manager objects, in
seconds since the last invalidation. The special value 0 means
that no Name-URI cache is maintained (i.e. the caching is
disabled).
"""
self.connect_timeout = connect_timeout
self.connect_retries = connect_retries
self.read_timeout = read_timeout
self.read_retries = read_retries
self.max_redirects = max_redirects
self.operation_timeout = operation_timeout
self.status_timeout = status_timeout
self.name_uri_cache_timetolive = name_uri_cache_timetolive
# Read retries only for these HTTP methods:
self.allowed_methods = {'GET'}
_attrs = ('connect_timeout', 'connect_retries', 'read_timeout',
'read_retries', 'max_redirects', 'operation_timeout',
'status_timeout', 'name_uri_cache_timetolive',
'allowed_methods')
[docs]
def override_with(self, override_config):
"""
Return a new configuration object that represents the configuration
from this configuration object acting as a default, and the specified
configuration object overriding that default for any of its
attributes that are not `None`.
Parameters:
override_config (:class:`~zhmcclient.RetryTimeoutConfig`):
The configuration object overriding the defaults defined in this
configuration object.
Returns:
:class:`~zhmcclient.RetryTimeoutConfig`:
A new configuration object representing this configuration object,
overridden by the specified configuration object.
"""
ret = RetryTimeoutConfig()
for attr in RetryTimeoutConfig._attrs:
value = getattr(self, attr)
if override_config and getattr(override_config, attr) is not None:
value = getattr(override_config, attr)
setattr(ret, attr, value)
return ret
[docs]
def get_password_interface(host, userid):
"""
Interface to the password retrieval function that is invoked by
:class:`~zhmcclient.Session` if no password is provided.
Parameters:
host (string): Hostname or IP address of the HMC
userid (string): Userid on the HMC
Returns:
string: Password of the userid on the HMC
"""
raise NotImplementedError
def _headers_for_logging(headers):
"""
Return the input headers dict with blanked out values for any headers that
carry sensitive information, so that it can be logged or displayed.
The headers argument is not modified; if it needs to be changed, a copy is
made that is changed.
"""
if headers and 'X-API-Session' in headers:
headers = headers.copy()
headers['X-API-Session'] = BLANKED_OUT
return headers
[docs]
class Session:
"""
A session to the HMC, optionally in context of an HMC user.
The session supports operations that require to be authenticated, as well
as operations that don't (e.g. obtaining the API version).
The session can keep statistics about the elapsed time for issuing HTTP
requests against the HMC API. Instance variable
:attr:`~zhmcclient.Session.time_stats_keeper` is used to enable/disable the
measurements, and to print the statistics.
HMC/SE version requirements: None
"""
default_rt_config = RetryTimeoutConfig(
connect_timeout=DEFAULT_CONNECT_TIMEOUT,
connect_retries=DEFAULT_CONNECT_RETRIES,
read_timeout=DEFAULT_READ_TIMEOUT,
read_retries=DEFAULT_READ_RETRIES,
max_redirects=DEFAULT_MAX_REDIRECTS,
operation_timeout=DEFAULT_OPERATION_TIMEOUT,
status_timeout=DEFAULT_STATUS_TIMEOUT,
name_uri_cache_timetolive=DEFAULT_NAME_URI_CACHE_TIMETOLIVE,
)
def __init__(self, host, userid=None, password=None, session_id=None,
get_password=None, retry_timeout_config=None,
port=DEFAULT_HMC_PORT, verify_cert=True):
# pylint: disable=line-too-long
"""
Creating a session object will not immediately cause a logon to be
attempted; the logon is deferred until needed.
There are several alternatives for specifying the authentication
related parameters:
* `userid`/`password` only: The session is initially in a logged-off
state and subsequent operations that require logon will use the
specified userid and password to automatically log on. The returned
session-id will be stored in this session object. Subsequent
operations that require logon will use that session-id. Once the HMC
expires that session-id, subsequent operations that require logon
will cause a re-logon with the specified userid and password.
* `userid`/`password` and `session_id`: The specified session-id will
be stored in this session object, so that the session is initially in
a logged-on state. Subsequent operations that require logon will use
that session-id. Once the HMC expires that session-id, subsequent
operations that require logon will cause a re-logon with the
specified userid/password.
In this case, the `host` parameter must specify the single HMC that
has that session.
* `session_id` only: The specified session-id will be stored in this
session object, so that the session is initially in a logged-on
state. Subsequent operations that require logon will use the stored
session-id. Once the HMC expires the session-id, subsequent
operations that require logon will cause an
:exc:`~zhmcclient.ServerAuthError` to be raised (because
userid/password have not been specified, so an automatic re-logon is
not possible).
In this case, the `host` parameter must specify the single HMC that
has that session.
* Neither `userid`/`password` nor `session_id`: Only operations that do
not require logon, are possible.
Parameters:
host (:term:`string` or iterable of :term:`string`):
HMC host or list of HMC hosts to try from.
For valid formats, see the :attr:`~zhmcclient.Session.host`
property.
If `session_id` is specified, this must be the single HMC that has
that session.
Must not be `None`.
userid (:term:`string`):
Userid of the HMC user to be used, or `None`.
password (:term:`string`):
Password of the HMC user to be used, if `userid` was specified.
session_id (:term:`string`):
Session-id to be used for this session, or `None`.
get_password (:term:`callable`):
A password retrieval function, or `None`.
If provided, this function will be called if a password is needed
but not provided. This mechanism can be used for example by command
line interfaces for prompting for the password.
The password retrieval function must follow the interface
defined in :func:`~zhmcclient.get_password_interface`.
retry_timeout_config (:class:`~zhmcclient.RetryTimeoutConfig`):
The retry/timeout configuration for this session for use by any of
its HMC operations, overriding any defaults.
`None` for an attribute in that configuration object means that the
default value will be used for that attribute.
`None` for the entire `retry_timeout_config` parameter means that a
default configuration will be used with the default values for all
of its attributes.
See :ref:`Constants` for the default values.
port (:term:`integer`):
HMC TCP port. Defaults to
:attr:`~zhmcclient._constants.DEFAULT_HMC_PORT`.
For details, see the :attr:`~zhmcclient.Session.port` property.
verify_cert (bool or :term:`string`):
Controls whether and how the client verifies the server certificate
presented by the HMC during SSL/TLS handshake:
* `False`: Do not verify the HMC certificate. Not verifying the HMC
certificate means the zhmcclient will not detect hostname
mismatches, expired certificates, revoked certificates, or
otherwise invalid certificates. Since this mode makes the
connection vulnerable to man-in-the-middle attacks, it is insecure
and should not be used in production environments.
* `True`: Verify the HMC certificate using the CA certificates from
the first of these locations:
- The file or directory in the REQUESTS_CA_BUNDLE env.var, if set
- The file or directory in the CURL_CA_BUNDLE env.var, if set
- The Python 'certifi' package (which contains the
`Mozilla Included CA Certificate List <https://wiki.mozilla.org/CA/Included_Certificates>`_).
* :term:`string`: Path name of a certificate file or directory.
Verify the HMC certificate using the CA certificates in that file
or directory.
For details, see the :ref:`HMC certificate` section.
*Added in version 0.31*
""" # noqa: E501
# pylint: enable=line-too-long
if isinstance(host, str):
self._hosts = [host]
else:
self._hosts = list(host)
assert len(self._hosts) >= 1
self._port = port
self._userid = userid
self._password = password
self._verify_cert = verify_cert
self._get_password = get_password
self._retry_timeout_config = self.default_rt_config.override_with(
retry_timeout_config)
self._headers = copy(_STD_HEADERS) # dict with standard HTTP headers
if session_id is not None:
# Create a logged-on state (nearly same state as in _do_logon())
self._session_id = session_id
self._session = self._new_session(self.retry_timeout_config)
self._headers['X-API-Session'] = session_id
assert len(self._hosts) == 1
self._actual_host = self._hosts[0]
self._base_url = \
self._create_base_url(self._actual_host, self._port)
# The following are set in _do_logon()) but not here:
self._session_credential = None
self._object_topic = None
self._job_topic = None
else:
# Create a logged-off state (same state as in _do_logoff())
self._session_id = None
self._session = None
self._actual_host = None
self._base_url = None
self._session_credential = None
self._object_topic = None
self._job_topic = None
self._time_stats_keeper = TimeStatsKeeper()
self._auto_updater = AutoUpdater(self)
[docs]
def __repr__(self):
"""
Return a string with the state of this session, for debug purposes.
"""
headers = _headers_for_logging(self.headers)
ret = (
f"{repr_obj_id(self)} (\n"
f" _hosts={self._hosts!r},\n"
f" _userid={self._userid!r},\n"
f" _password='...',\n"
f" _verify_cert={self._verify_cert!r},\n"
f" _get_password={self._get_password!r},\n"
f" _retry_timeout_config={self._retry_timeout_config!r},\n"
f" _actual_host={self._actual_host!r},\n"
f" _base_url={self._base_url!r},\n"
f" _headers={headers!r},\n"
f" _session_id={BLANKED_OUT!r},\n"
f" _session={self._session!r}\n"
f" _object_topic={self._object_topic!r}\n"
f" _job_topic={self._job_topic!r}\n"
f" _auto_updater={self._auto_updater!r}\n"
")")
return ret
@property
def host(self):
"""
:term:`string` or list of :term:`string`: HMC host or redundant HMC
hosts to use. The first working HMC from this list will actually be
used. The working state of the HMC is detrmined using the
'Query API Version' operation for which no authentication is needed.
Each host will be in one of the following formats:
* a short or fully qualified DNS hostname
* a literal (= dotted) IPv4 address
* a literal IPv6 address, formatted as defined in :term:`RFC3986`
with the extensions for zone identifiers as defined in
:term:`RFC6874`, supporting ``-`` (minus) for the delimiter
before the zone ID string, as an additional choice to ``%25``
"""
if len(self._hosts) == 1:
host = self._hosts[0]
else:
host = self._hosts
return host
@property
def actual_host(self):
"""
:term:`string` or `None`: The HMC host that is actually used for this
session, if the session is in the logged-on state. `None`, if the
session is in the logged-off state.
The HMC host will be in one of the following formats:
* a short or fully qualified DNS hostname
* a literal (= dotted) IPv4 address
* a literal IPv6 address, formatted as defined in :term:`RFC3986`
with the extensions for zone identifiers as defined in
:term:`RFC6874`, supporting ``-`` (minus) for the delimiter
before the zone ID string, as an additional choice to ``%25``
"""
return self._actual_host
@property
def port(self):
"""
:term:`integer`: HMC TCP port that is used for this session.
"""
return self._port
@property
def userid(self):
"""
:term:`string`: HMC userid that is used for this session.
If `None`, only operations that do not require authentication, can be
performed.
"""
return self._userid
@property
def verify_cert(self):
"""
bool or :term:`string`: Controls whether and how the client verifies
server certificate presented by the HMC during SSL/TLS handshake.
For details, see the same-named init parameter.
"""
return self._verify_cert
@property
def get_password(self):
"""
The password retrieval function, or `None`.
The password retrieval function must follow the interface defined in
:func:`~zhmcclient.get_password_interface`.
"""
return self._get_password
@property
def retry_timeout_config(self):
"""
:class:`~zhmcclient.RetryTimeoutConfig`: The effective retry/timeout
configuration for this session for use by any of its HMC operations,
taking into account the defaults and the session-specific overrides.
"""
return self._retry_timeout_config
@property
def base_url(self):
"""
:term:`string` or `None`: Base URL of the HMC that is actually used for
this session, if the session is in the logged-on state. `None`, if the
session is in the logged-off state.
Example:
.. code-block:: text
https://myhmc.acme.com:6794
"""
return self._base_url
@property
def headers(self):
"""
:term:`header dict`: HTTP headers that are used in requests sent
for this session.
Initially, this is the following set of headers:
.. code-block:: text
Content-type: application/json
Accept: */*
When the session is logged on to the HMC, the session token is added
to these headers:
.. code-block:: text
X-API-Session: ...
"""
return self._headers
@property
def time_stats_keeper(self):
"""
The time statistics keeper (for a usage example, see section
:ref:`Time Statistics`).
"""
return self._time_stats_keeper
@property
def session_id(self):
"""
:term:`string` or `None`: Session ID (= HMC session token) used for this
session, if the session is in the logged-on state. `None`, if the
session is in the logged-off state.
In the logged-off state, any request that requires logon will first
cause a session to be created on the HMC and will store the session ID
returned by the HMC in this property.
In the logged-on state, the session ID stored in this property will be
used for any requests to the HMC.
"""
return self._session_id
@property
def session_credential(self):
"""
:term:`string` or `None`: Session credential for this session returned
by the HMC, if the session is in the logged-on state. `None`, if the
session is in the logged-off state.
"""
return self._session_credential
@property
def session(self):
"""
:term:`string` or `None`: :class:`requests.Session` object for this
session, if the session is in the logged-on state. `None`, if the
session is in the logged-off state.
"""
return self._session
@property
def object_topic(self):
"""
:term:`string` or `None`: Name of the notification topic the HMC will
use to send object-related notification messages to this session, if
the session is in the logged-on state. `None`, if the session is in the
logged-off state.
The associated topic type is "object-notification".
"""
return self._object_topic
@property
def job_topic(self):
"""
:term:`string` or `None`: Name of the notification topic the HMC will
use to send job notification messages to this session, if the session
is in the logged-on state. `None`, if the session is in the logged-off
state.
The associated topic type is "job-notification".
"""
return self._job_topic
@property
def auto_updater(self):
"""
:class:`~zhmcclient.AutoUpdater`: Updater for
:ref:`auto-updating` of resource and manager objects.
"""
return self._auto_updater
[docs]
@logged_api_call
def logon(self, verify=False):
"""
Make sure this session object is logged on to the HMC.
If `verify=False`, this method determines the logged-on state of this
session object based on whether there is a session ID set in this
session object. If a session ID is set, it is assumed to be valid and
no new session is created on the HMC. Otherwise, a new session will be
created on the HMC.
If `verify=True`, this method determines the logged-on state of this
session object in addition by performing a read operation on the HMC
that requires to be logged on but no specific authorizations. If a
session ID is set and if that operation succeeds, no new session is
created on the HMC. Any failure of that read operation will be ignored.
Otherwise, a new session will be created on the HMC.
When a new session has been successfully created on the HMC, the
:attr:`session_id` attribute of this session object will be set to the
session ID returned by the HMC to put it into the logged-on state.
Any exceptions raised from this method are always related to the
creation of a new session on the HMC - any failures of the read
operation in the verification case are always ignored.
Parameters:
verify (bool): Verify the validity of an existing session ID.
Raises:
:exc:`~zhmcclient.HTTPError`
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ClientAuthError`
:exc:`~zhmcclient.ServerAuthError`
:exc:`~zhmcclient.ConnectionError`
"""
need_logon = False
if self._session_id is None:
need_logon = True
elif verify:
try:
self.get('/api/console', logon_required=False,
renew_session=False)
except Error:
need_logon = True
if need_logon:
self._do_logon()
[docs]
@logged_api_call
def logoff(self, verify=False):
# pylint: disable=unused-argument
"""
Make sure this session object is logged off from the HMC.
If a session ID is set in this session object, its session will be
deleted on the HMC. If that delete operation fails due to an invalid
session ID, that failure will be ignored. Any other failures of that
delete operation will be raised as exceptions.
When the session has been successfully deleted on the HMC, the
:attr:`session_id` attribute of this session object will be set to
`None` to put it into the logged-off state.
Parameters:
verify (bool): Deprecated: This parameter will be ignored.
Raises:
:exc:`~zhmcclient.HTTPError`
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ConnectionError`
"""
if self._session_id:
self._do_logoff()
[docs]
@logged_api_call
def is_logon(self, verify=False):
"""
Return a boolean indicating whether this session object is logged on to
the HMC.
If `verify=False`, this method determines the logged-on state based
on whether there is a session ID set in this object. If a session ID is
set, it is assumed to be valid, and `True` is returned. Otherwise,
`False` is returned. In that case, no exception is ever raised.
If `verify=True`, this method determines the logged-on state in
addition by verifying a session ID that is set, by performing a read
operation on the HMC that requires to be logged on but no specific
authorizations. If a session ID is set and if that read operation
succeeds, `True` is returned. If no session ID is set or if that read
operation fails due to an invalid session ID, `False` is returned.
Any other failures of that read operation are raised as exceptions,
because that indicates that a verification with the HMC could not be
performed.
Parameters:
verify (bool): Verify the validity of an existing session ID.
Raises:
:exc:`~zhmcclient.HTTPError`
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ConnectionError`
"""
if self._session_id is None:
return False
if verify:
try:
self.get('/api/console', logon_required=False,
renew_session=False)
except ServerAuthError:
return False
return True
def _do_logon(self):
"""
Log on, unconditionally. This can be used to re-logon.
This requires credentials to be provided.
Raises:
:exc:`~zhmcclient.HTTPError`
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ClientAuthError`
:exc:`~zhmcclient.ServerAuthError`
:exc:`~zhmcclient.ConnectionError`
"""
if self._userid is None:
raise ClientAuthError("Userid is not provided.")
# Determine working HMC for this session
self._actual_host = self._determine_actual_host()
self._base_url = self._create_base_url(self._actual_host, self._port)
if self._password is None:
if self._get_password:
self._password = \
self._get_password(self._actual_host, self._userid)
else:
raise ClientAuthError("Password is not provided.")
# Create an HMC session
logon_uri = '/api/sessions'
logon_body = {
'userid': self._userid,
'password': self._password
}
self._headers.pop('X-API-Session', None) # Just in case
self._session = self._new_session(self.retry_timeout_config)
logon_res = self.post(logon_uri, body=logon_body, logon_required=False)
self._session_id = logon_res['api-session']
self._session_credential = logon_res['session-credential']
self._headers['X-API-Session'] = self._session_id
self._object_topic = logon_res['notification-topic']
self._job_topic = logon_res['job-notification-topic']
@staticmethod
def _create_base_url(host, port):
"""
Encapsulates how the base URL of the HMC is constructed.
"""
return f"{_HMC_SCHEME}://{host}:{port}"
def _determine_actual_host(self):
"""
Determine the actual HMC host to be used.
If a single HMC host is specified, that host is used without further
verification as to whether it is available.
If more than one HMC host is specified, the first available host is
used. Availability of the HMC is determined using the
'Query API Version' operation, for which no logon is required.
If no available HMC can be found, raises the ConnectionError of the
last HMC that was tried.
"""
if len(self._hosts) == 1:
host = self._hosts[0]
HMC_LOGGER.debug("Using the only HMC specified without verifying "
"its availability: %s", host)
return host
last_exc = None
for host in self._hosts:
HMC_LOGGER.debug("Trying HMC for availability: %s", host)
self._base_url = self._create_base_url(host, self._port)
try:
self.get('/api/version', logon_required=False,
renew_session=False)
except ConnectionError as exc:
last_exc = exc
continue
HMC_LOGGER.debug("Using available HMC: %s", host)
return host
HMC_LOGGER.debug("Did not find an available HMC in: %s",
self._hosts)
raise last_exc
@staticmethod
def _new_session(retry_timeout_config):
"""
Return a new `requests.Session` object.
"""
retry = urllib3.Retry(
total=retry_timeout_config.connect_retries,
connect=retry_timeout_config.connect_retries,
read=retry_timeout_config.read_retries,
allowed_methods=retry_timeout_config.allowed_methods,
redirect=retry_timeout_config.max_redirects)
session = requests.Session()
session.mount('https://',
requests.adapters.HTTPAdapter(max_retries=retry))
session.mount('http://',
requests.adapters.HTTPAdapter(max_retries=retry))
return session
def _do_logoff(self):
"""
Log off, unconditionally.
This deletes the session on the HMC. If that deletion operation fails
due to an invalid session ID, that failure is ignored.
Raises:
:exc:`~zhmcclient.HTTPError`
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ConnectionError`
"""
session_uri = '/api/sessions/this-session'
try:
self.delete(session_uri, logon_required=False, renew_session=False)
except (ServerAuthError, ConnectionError):
# HMC shutdown or broken network causes ConnectionError.
# Invalid credentials cause ServerAuthError.
pass
self._actual_host = None
self._base_url = None
self._session_id = None
self._session = None
self._headers.pop('X-API-Session', None)
self._object_topic = None
self._job_topic = None
@staticmethod
def _log_http_request(
method, url, resource, headers=None, content=None,
content_len=None):
"""
Log the HTTP request of an HMC REST API call, at the debug level.
Parameters:
method (:term:`string`): HTTP method name in upper case, e.g. 'GET'
url (:term:`string`): HTTP URL (base URL and operation URI)
headers (iterable): HTTP headers used for the request
content (:term:`string`): HTTP body (aka content) used for the
request (byte string or unicode string)
content_len (int): Length of content in Bytes, or `None` for
determining the length from the content string
"""
content_msg = None
if content is not None:
if isinstance(content, bytes):
content = content.decode('utf-8', errors='ignore')
assert isinstance(content, str)
if content_len is None:
content_len = len(content) # may change after JSON conversion
try:
content_dict = json2dict(content)
except ValueError:
# If the content is not JSON, we assume it does not contain
# structured data such as a password or session IDs.
pass
else:
if 'password' in content_dict:
content_dict['password'] = BLANKED_OUT
content = dict2json(content_dict)
trunc = 30000
if content_len > trunc:
content_label = f"content(first {trunc} B of {content_len} B)"
content_msg = content[0:trunc] + '...(truncated)'
else:
content_label = f'content({content_len} B)'
content_msg = content
else:
content_label = 'content'
content_msg = content
if resource:
names = []
res_class = resource.manager.class_name
while resource:
# Using resource.name gets into an infinite recursion when
# the resource name is not present, due to pulling the
# properties in that case. We take the careful approach.
name_prop = resource.manager.name_prop
name = resource.properties.get(name_prop, '<unknown>')
names.insert(0, name)
resource = resource.manager.parent
res_str = f" ({res_class} {'.'.join(names)})"
else:
res_str = ""
HMC_LOGGER.debug("Request: %s %s%s, headers: %r, %s: %r",
method, url, res_str, _headers_for_logging(headers),
content_label, content_msg)
@staticmethod
def _log_http_response(
method, url, resource, status, headers=None, content=None):
"""
Log the HTTP response of an HMC REST API call, at the debug level.
Parameters:
method (:term:`string`): HTTP method name in upper case, e.g. 'GET'
url (:term:`string`): HTTP URL (base URL and operation URI)
status (integer): HTTP status code
headers (iterable): HTTP headers returned in the response
content (:term:`string`): HTTP body (aka content) returned in the
response (byte string or unicode string)
"""
if content is not None:
if isinstance(content, bytes):
content = content.decode('utf-8')
assert isinstance(content, str)
content_len = len(content) # may change after JSON conversion
try:
content_dict = json2dict(content)
except ValueError:
# If the content is not JSON (e.g. response from metrics
# context retrieval), we assume it does not contain structured
# data such as a password or session IDs.
pass
else:
if 'request-headers' in content_dict:
headers_dict = content_dict['request-headers']
if 'x-api-session' in headers_dict:
headers_dict['x-api-session'] = BLANKED_OUT
if 'api-session' in content_dict:
content_dict['api-session'] = BLANKED_OUT
if 'session-credential' in content_dict:
content_dict['session-credential'] = BLANKED_OUT
content = dict2json(content_dict)
if status >= 400:
content_label = 'content'
content_msg = content
else:
trunc = 30000
if content_len > trunc:
content_label = \
f"content(first {trunc} B of {content_len} B)"
content_msg = content[0:trunc] + '...(truncated)'
else:
content_label = f'content({len(content)} B)'
content_msg = content
else:
content_label = 'content'
content_msg = content
if resource:
names = []
res_class = resource.manager.class_name
while resource:
# Using resource.name gets into an infinite recursion when
# the resource name is not present, due to pulling the
# properties in that case. We take the careful approach.
name_prop = resource.manager.name_prop
name = resource.properties.get(name_prop, '<unknown>')
names.insert(0, name)
resource = resource.manager.parent
res_str = f" ({res_class} {'.'.join(names)})"
else:
res_str = ""
HMC_LOGGER.debug("Respons: %s %s%s, status: %s, "
"headers: %r, %s: %r",
method, url, res_str, status,
_headers_for_logging(headers),
content_label, content_msg)
[docs]
@logged_api_call
def get(self, uri, resource=None, logon_required=True, renew_session=True):
"""
Perform the HTTP GET method against the resource identified by a URI.
A set of standard HTTP headers is automatically part of the request.
If the HMC session token is expired, this method re-logs on and retries
the operation.
Parameters:
uri (:term:`string`):
Relative URI path of the resource, e.g. "/api/session".
This URI is relative to the base URL of the session (see
the :attr:`~zhmcclient.Session.base_url` property).
Must not be `None`.
logon_required (bool):
Boolean indicating whether the operation requires that the session
is logged on to the HMC. For example, the API version retrieval
operation does not require that.
renew_session (bool):
Boolean indicating whether the session should be renewed in case
it is expired.
Returns:
:term:`json object` with the operation result.
Raises:
:exc:`~zhmcclient.HTTPError`
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ClientAuthError`
:exc:`~zhmcclient.ServerAuthError`
:exc:`~zhmcclient.ConnectionError`
"""
if logon_required:
self.logon()
elif self._base_url is None:
self._actual_host = self._determine_actual_host()
self._base_url = \
self._create_base_url(self._actual_host, self._port)
url = self._base_url + uri
self._log_http_request('GET', url, resource=resource,
headers=self.headers)
stats = self.time_stats_keeper.get_stats('get ' + uri)
stats.begin()
req = self._session or requests
req_timeout = (self.retry_timeout_config.connect_timeout,
self.retry_timeout_config.read_timeout)
try:
result = req.get(url, headers=self.headers, verify=self.verify_cert,
timeout=req_timeout)
# Note: The requests method may raise OSError/IOError in case of
# HMC certificate validation issues (e.g. incorrect cert path)
except (requests.exceptions.RequestException, OSError) as exc:
_handle_request_exc(exc, self.retry_timeout_config)
finally:
stats.end()
self._log_http_response('GET', url, resource=resource,
status=result.status_code,
headers=result.headers,
content=result.content)
if result.status_code == 200:
return _result_object(result)
if result.status_code == 403:
result_object = _result_object(result)
reason = result_object.get('reason', None)
message = result_object.get('message', None)
HMC_LOGGER.debug("Received HTTP status 403.%d on GET %s: %s",
reason, uri, message)
if reason in (4, 5):
# 403.4: No session ID was provided
# 403.5: Session ID was invalid
if renew_session:
self._do_logon()
return self.get(
uri, resource=resource, logon_required=False,
renew_session=False)
if reason == 1:
# Login user's authentication is fine; this is an authorization
# issue, so we don't raise ServerAuthError.
raise HTTPError(result_object)
msg = result_object.get('message', None)
raise ServerAuthError(
"HTTP authentication failed with "
f"{result.status_code},{reason}: {msg}",
HTTPError(result_object))
result_object = _result_object(result)
raise HTTPError(result_object)
[docs]
@logged_api_call
def post(self, uri, resource=None, body=None, logon_required=True,
wait_for_completion=False, operation_timeout=None,
renew_session=True):
"""
Perform the HTTP POST method against the resource identified by a URI,
using a provided request body.
A set of standard HTTP headers is automatically part of the request.
HMC operations using HTTP POST are either synchronous or asynchronous.
Asynchronous operations return the URI of an asynchronously executing
job that can be queried for status and result.
Examples for synchronous operations:
* With no result: "Logon", "Update CPC Properties"
* With a result: "Create Partition"
Examples for asynchronous operations:
* With no result: "Start Partition"
The `wait_for_completion` parameter of this method can be used to deal
with asynchronous HMC operations in a synchronous way.
If executing the operation reveals that the HMC session token is
expired, this method re-logs on and retries the operation.
The timeout and retry
Parameters:
uri (:term:`string`):
Relative URI path of the resource, e.g. "/api/session".
This URI is relative to the base URL of the session (see the
:attr:`~zhmcclient.Session.base_url` property).
Must not be `None`.
body (:term:`json object` or :term:`string` or file-like object):
The HTTP request body (payload).
If a JSON object (=dict) is provided, it will be serialized into
a UTF-8 encoded binary string.
If a Unicode string is provided, it will be encoded into a UTF-8
encoded binary string.
If a binary string is provided, it will be used unchanged.
If a file-like object is provided, it must return binary strings,
i.e. the file must have been opened in binary mode.
`None` means the same as an empty dictionary, namely that no HTTP
body is included in the request.
logon_required (bool):
Boolean indicating whether the operation requires that the session
is logged on to the HMC. For example, the "Logon" operation does
not require that.
wait_for_completion (bool):
Boolean controlling whether this method should wait for completion
of the requested asynchronous HMC operation.
A value of `True` will cause an additional entry in the time
statistics to be created that represents the entire asynchronous
operation including the waiting for its completion.
That time statistics entry will have a URI that is the targeted
URI, appended with "+completion".
For synchronous HMC operations, this parameter has no effect on
the operation execution or on the return value of this method, but
it should still be set (or defaulted) to `False` in order to avoid
the additional entry in the time statistics.
operation_timeout (:term:`number`):
Timeout in seconds, when waiting for completion of an asynchronous
operation. The special value 0 means that no timeout is set. `None`
means that the default async operation timeout of the session is
used.
For `wait_for_completion=True`, a
:exc:`~zhmcclient.OperationTimeout` is raised when the timeout
expires.
For `wait_for_completion=False`, this parameter has no effect.
renew_session (bool):
Boolean indicating whether the session should be renewed in case
it is expired.
Returns:
: A :term:`json object` or `None` or a :class:`~zhmcclient.Job`
object, as follows:
* For synchronous HMC operations, and for asynchronous HMC
operations with `wait_for_completion=True`:
If this method returns, the HMC operation has completed
successfully (otherwise, an exception is raised).
For asynchronous HMC operations, the associated job has been
deleted.
The return value is the result of the HMC operation as a
:term:`json object`, or `None` if the operation has no result.
See the section in the :term:`HMC API` book about the specific
HMC operation for a description of the members of the returned
JSON object.
* For asynchronous HMC operations with `wait_for_completion=False`:
If this method returns, the asynchronous execution of the HMC
operation has been started successfully as a job on the HMC (if
the operation could not be started, an exception is raised).
The return value is a :class:`~zhmcclient.Job` object
representing the job on the HMC.
Raises:
:exc:`~zhmcclient.HTTPError`
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ClientAuthError`
:exc:`~zhmcclient.ServerAuthError`
:exc:`~zhmcclient.ConnectionError`
:exc:`~zhmcclient.OperationTimeout`: The timeout expired while
waiting for completion of the asynchronous operation.
:exc:`TypeError`: Body has invalid type.
"""
if logon_required:
self.logon()
elif self._base_url is None:
self._actual_host = self._determine_actual_host()
self._base_url = \
self._create_base_url(self._actual_host, self._port)
url = self._base_url + uri
headers = self.headers.copy() # Standard headers
log_len = None
if body is None:
data = None
log_data = None
elif isinstance(body, dict):
data = json.dumps(body)
# Produces unicode string on py3, and unicode or byte string on py2.
# Content-type is already set to 'application/json' in standard
# headers.
if isinstance(data, str):
log_data = data
data = data.encode('utf-8')
else:
log_data = data
elif isinstance(body, str):
data = body.encode('utf-8')
log_data = body
headers['Content-type'] = 'application/octet-stream'
elif isinstance(body, bytes):
data = body
log_data = body
headers['Content-type'] = 'application/octet-stream'
elif isinstance(body, Iterable):
# File-like objects, e.g. io.BufferedReader or io.TextIOWrapper
# returned from open() or io.open().
data = body
try:
mode = body.mode
except AttributeError:
mode = 'unknown'
log_data = f"<file-like object with mode {mode}>"
log_len = -1
headers['Content-type'] = 'application/octet-stream'
else:
raise TypeError(f"Body has invalid type: {type(body)}")
self._log_http_request('POST', url, resource=resource, headers=headers,
content=log_data, content_len=log_len)
req = self._session or requests
req_timeout = (self.retry_timeout_config.connect_timeout,
self.retry_timeout_config.read_timeout)
if wait_for_completion:
stats_total = self.time_stats_keeper.get_stats(
'post ' + uri + '+completion')
stats_total.begin()
try:
stats = self.time_stats_keeper.get_stats('post ' + uri)
stats.begin()
try:
if data is None:
result = req.post(url, headers=headers,
verify=self.verify_cert,
timeout=req_timeout)
else:
result = req.post(url, data=data, headers=headers,
verify=self.verify_cert,
timeout=req_timeout)
# Note: The requests method may raise OSError/IOError in case of
# HMC certificate validation issues (e.g. incorrect cert path)
except (requests.exceptions.RequestException, OSError) \
as exc:
_handle_request_exc(exc, self.retry_timeout_config)
finally:
stats.end()
self._log_http_response('POST', url, resource=resource,
status=result.status_code,
headers=result.headers,
content=result.content)
if result.status_code in (200, 201):
return _result_object(result)
if result.status_code == 204:
# No content
return None
if result.status_code == 202:
if result.content == b'':
# Some operations (e.g. "Restart Console",
# "Shutdown Console" or "Cancel Job") return 202
# with no response content.
return None
# This is the most common case to return 202: An
# asynchronous job has been started.
result_object = _result_object(result)
job_uri = result_object['job-uri']
job = Job(self, job_uri, 'POST', uri)
if wait_for_completion:
return job.wait_for_completion(operation_timeout)
return job
if result.status_code == 403:
result_object = _result_object(result)
reason = result_object.get('reason', None)
message = result_object.get('message', None)
HMC_LOGGER.debug("Received HTTP status 403.%d on GET %s: %s",
reason, uri, message)
if reason in (4, 5):
# 403.4: No session ID was provided
# 403.5: Session ID was invalid
if renew_session:
self._do_logon()
return self.post(
uri, resource=resource, body=body,
logon_required=False, renew_session=False,
wait_for_completion=wait_for_completion,
operation_timeout=operation_timeout)
if reason == 1:
# Login user's authentication is fine; this is an
# authorization issue, so we don't raise ServerAuthError.
raise HTTPError(result_object)
msg = result_object.get('message', None)
raise ServerAuthError(
"HTTP authentication failed with "
f"{result.status_code},{reason}: {msg}",
HTTPError(result_object))
result_object = _result_object(result)
raise HTTPError(result_object)
finally:
if wait_for_completion:
stats_total.end()
[docs]
@logged_api_call
def delete(
self, uri, resource=None, logon_required=True, renew_session=True):
"""
Perform the HTTP DELETE method against the resource identified by a
URI.
A set of standard HTTP headers is automatically part of the request.
If the HMC session token is expired, this method re-logs on and retries
the operation.
Parameters:
uri (:term:`string`):
Relative URI path of the resource, e.g.
"/api/session/{session-id}".
This URI is relative to the base URL of the session (see
the :attr:`~zhmcclient.Session.base_url` property).
Must not be `None`.
logon_required (bool):
Boolean indicating whether the operation requires that the session
is logged on to the HMC. For example, for the logoff operation, it
does not make sense to first log on.
renew_session (bool):
Boolean indicating whether the session should be renewed in case
it is expired. For example, for the logoff operation, it does not
make sense to do that.
Raises:
:exc:`~zhmcclient.HTTPError`
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ClientAuthError`
:exc:`~zhmcclient.ServerAuthError`
:exc:`~zhmcclient.ConnectionError`
"""
if logon_required:
self.logon()
elif self._base_url is None:
self._actual_host = self._determine_actual_host()
self._base_url = \
self._create_base_url(self._actual_host, self._port)
url = self._base_url + uri
self._log_http_request('DELETE', url, resource=resource,
headers=self.headers)
stats = self.time_stats_keeper.get_stats('delete ' + uri)
stats.begin()
req = self._session or requests
req_timeout = (self.retry_timeout_config.connect_timeout,
self.retry_timeout_config.read_timeout)
try:
result = req.delete(url, headers=self.headers,
verify=self.verify_cert, timeout=req_timeout)
# Note: The requests method may raise OSError/IOError in case of
# HMC certificate validation issues (e.g. incorrect cert path)
except (requests.exceptions.RequestException, OSError) as exc:
_handle_request_exc(exc, self.retry_timeout_config)
finally:
stats.end()
self._log_http_response('DELETE', url, resource=resource,
status=result.status_code,
headers=result.headers,
content=result.content)
if result.status_code in (200, 204):
return
if result.status_code == 403:
result_object = _result_object(result)
reason = result_object.get('reason', None)
message = result_object.get('message', None)
HMC_LOGGER.debug("Received HTTP status 403.%d on GET %s: %s",
reason, uri, message)
if reason in (4, 5):
# 403.4: No session ID was provided
# 403.5: Session ID was invalid
if renew_session:
self._do_logon()
self.delete(uri, resource=resource, logon_required=False,
renew_session=False)
return
if reason == 1:
# Login user's authentication is fine; this is an authorization
# issue, so we don't raise ServerAuthError.
raise HTTPError(result_object)
msg = result_object.get('message', None)
raise ServerAuthError(
"HTTP authentication failed with "
f"{result.status_code},{reason}: {msg}",
HTTPError(result_object))
result_object = _result_object(result)
raise HTTPError(result_object)
[docs]
@logged_api_call
def get_notification_topics(self):
"""
The 'Get Notification Topics' operation returns a structure that
describes the JMS notification topics associated with this session.
Returns:
: A list with one item for each notification topic. Each item is a
dictionary with the following keys:
* ``"topic-type"`` (string): Topic type, e.g. "job-notification".
* ``"topic-name"`` (string): Topic name; can be used for
subscriptions.
* ``"object-uri"`` (string): When topic-type is
"os-message-notification", this item is the canonical URI path
of the Partition for which this topic exists.
This field does not exist for the other topic types.
* ``"include-refresh-messages"`` (bool): When the topic-type is
"os-message-notification", this item indicates whether refresh
operating system messages will be sent on this topic.
"""
topics_uri = '/api/sessions/operations/get-notification-topics'
response = self.get(topics_uri)
return response['topics']
[docs]
def auto_update_subscribed(self):
"""
Return whether this session is currently subscribed for
:ref:`auto-updating`.
Return:
bool: Indicates whether session is subscribed.
"""
return self._auto_updater.is_open()
[docs]
@logged_api_call
def subscribe_auto_update(self):
"""
Subscribe this session for :ref:`auto-updating`, if not currently
subscribed.
When not yet subscribed, the session is also logged on.
When subscribed, object notifications will be sent by the HMC as
resource objects on the HMC change their properties or come or go.
These object notifications will be received by the client and will then
update the properties of any Python resource objects that are enabled
for auto-updating.
This method is automatically called by
:meth:`~zhmcclient.BaseResource.enable_auto_update` and thus does not
need to be called by the user.
"""
if not self._auto_updater.is_open():
self._auto_updater.open()
[docs]
@logged_api_call
def unsubscribe_auto_update(self):
"""
Unsubscribe this session from :ref:`auto-updating`, if
currently subscribed.
When unsubscribed, object notifications are no longer sent by the HMC.
This method is automatically called by
:meth:`~zhmcclient.BaseResource.disable_auto_update` and thus does not
need to be called by the user.
"""
if self._auto_updater.is_open():
self._auto_updater.close()
[docs]
class Job:
"""
A job on the HMC that performs an asynchronous HMC operation.
This class supports checking the job for completion, and waiting for job
completion.
"""
def __init__(self, session, uri, op_method, op_uri):
"""
Parameters:
session (:class:`~zhmcclient.Session`):
Session with the HMC.
Must not be `None`.
uri (:term:`string`):
Canonical URI of the job on the HMC.
Must not be `None`.
Example: ``"/api/jobs/{job-id}"``
op_method (:term:`string`):
Name of the HTTP method of the operation that is executing
asynchronously on the HMC.
Must not be `None`.
Example: ``"POST"``
op_uri (:term:`string`):
Canonical URI of the operation that is executing asynchronously on
the HMC.
Must not be `None`.
Example: ``"/api/partitions/{partition-id}/stop"``
"""
self._session = session
self._uri = uri
self._op_method = op_method
self._op_uri = op_uri
@property
def session(self):
"""
:class:`~zhmcclient.Session`: Session with the HMC.
"""
return self._session
@property
def uri(self):
"""
:term:`string`: Canonical URI of the job on the HMC.
Example: ``"/api/jobs/{job-id}"``
"""
return self._uri
@property
def op_method(self):
"""
:term:`string`: Name of the HTTP method of the operation that is
executing asynchronously on the HMC.
Example: ``"POST"``
"""
return self._op_method
@property
def op_uri(self):
"""
:term:`string`: Canonical URI of the operation that is executing
asynchronously on the HMC.
Example: ``"/api/partitions/{partition-id}/stop"``
"""
return self._op_uri
[docs]
@logged_api_call
def query_status(self):
"""
Get the current status of this job, and if completed also the
operation results.
This method performs the "Query Job Status" operation on the job.
This is a low level operation, consider using
:meth:`~zhmcclient.Job.check_for_completion` or
:meth:`~zhmcclient.Job.wait_for_completion` instead.
If the job no longer exists, :exc:`~zhmcclient.HTTPError` is raised
with status code 404 and reason code 1.
Returns:
tuple(job_status, op_status, op_reason, op_result): With the following
items:
* job_status(string): Job status, one of:
- "running" - indicates that the job was found and it has not ended
at the time of the query.
- "cancel-pending" - indicates that the job was found and it has
not ended but cancellation has been requested.
- "canceled" - indicates that the job's normal course of execution
was interrupted by a cancel request, and the job has now ended.
- "complete" - indicates that the job was found and has completed
the operation, and the job has now ended.
* op_status(int): HTTP status code of the operation performed by
the job. Will be `None` if the job has not ended.
* op_reason(int): HTTP reason code of the operation performed by
the job. Will be `None` if the job has not ended.
* op_result(dict): Result of the operation performed by
the job, as described in the zhmcclient method that performed
the operation. Will be `None` if the job has not ended.
Raises:
:exc:`~zhmcclient.HTTPError`
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ClientAuthError`
:exc:`~zhmcclient.ServerAuthError`
:exc:`~zhmcclient.ConnectionError`
"""
try:
result = self.session.get(self.uri)
except Error as exc:
HMC_LOGGER.debug("Request: GET %s failed with %s: %s",
self.uri, exc.__class__.__name__, exc)
raise
job_status = result['status']
op_status = result.get('job-status-code', None)
op_reason = result.get('job-reason-code', None)
op_result = result.get('job-results', None)
return job_status, op_status, op_reason, op_result
[docs]
@logged_api_call
def delete(self):
"""
Delete this ended job on the HMC.
This method performs the "Delete Completed Job Status" operation on the
job.
This is a low level operation, consider using
:meth:`~zhmcclient.Job.check_for_completion` or
:meth:`~zhmcclient.Job.wait_for_completion` instead, which delete the
ended job.
If the job has not ended (i.e. its `status` property is not "canceled"
or"complete"), :exc:`~zhmcclient.HTTPError` is raised with status code
409 and reason code 40.
If the job no longer exists, :exc:`~zhmcclient.HTTPError` is raised
with status code 404 and reason code 1.
Raises:
:exc:`~zhmcclient.HTTPError`
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ClientAuthError`
:exc:`~zhmcclient.ServerAuthError`
:exc:`~zhmcclient.ConnectionError`
"""
try:
self.session.delete(self.uri)
except Error as exc:
HMC_LOGGER.debug("Request: DELETE %s failed with %s: %s",
self.uri, exc.__class__.__name__, exc)
raise
[docs]
@logged_api_call
def check_for_completion(self):
"""
Check once for completion of the job and return completion status and
result if it has completed.
If the job completed in error, an :exc:`~zhmcclient.HTTPError`
exception is raised.
Returns:
: A tuple (status, result) with:
* status (:term:`string`): Completion status of the job, as
returned in the ``status`` field of the response body of the
"Query Job Status" HMC operation, as follows:
* ``"complete"``: Job completed (successfully).
* any other value: Job is not yet complete.
* result (:term:`json object` or `None`): `None` for incomplete
jobs. For completed jobs, the result of the original asynchronous
operation that was performed by the job, from the ``job-results``
field of the response body of the "Query Job Status" HMC
operation. That result is a :term:`json object` as described
for the asynchronous operation, or `None` if the operation has no
result.
Raises:
:exc:`~zhmcclient.HTTPError`: The job completed in error, or the job
status cannot be retrieved, or the job cannot be deleted.
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ClientAuthError`
:exc:`~zhmcclient.ServerAuthError`
:exc:`~zhmcclient.ConnectionError`
"""
try:
job_result_obj = self.session.get(self.uri)
except Error as exc:
HMC_LOGGER.debug("Request: GET %s failed with %s: %s",
self.uri, exc.__class__.__name__, exc)
raise
job_status = job_result_obj['status']
if job_status == 'complete':
self.session.delete(self.uri)
op_status_code = job_result_obj['job-status-code']
if op_status_code in (200, 201):
op_result_obj = job_result_obj.get('job-results', None)
elif op_status_code == 204:
# No content
op_result_obj = None
else:
error_result_obj = job_result_obj.get('job-results', None)
if not error_result_obj:
message = None
elif 'message' in error_result_obj:
message = error_result_obj['message']
elif 'error' in error_result_obj:
message = error_result_obj['error']
else:
message = None
error_obj = {
'http-status': op_status_code,
'reason': job_result_obj['job-reason-code'],
'message': message,
'request-method': self.op_method,
'request-uri': self.op_uri,
}
raise HTTPError(error_obj)
else:
op_result_obj = None
return job_status, op_result_obj
[docs]
@logged_api_call
def wait_for_completion(self, operation_timeout=None):
"""
Wait for completion of the job, then delete the job on the HMC and
return the result of the original asynchronous HMC operation, if it
completed successfully.
If the job completed in error, an :exc:`~zhmcclient.HTTPError`
exception is raised.
Parameters:
operation_timeout (:term:`number`):
Timeout in seconds, when waiting for completion of the job. The
special value 0 means that no timeout is set. `None` means that the
default async operation timeout of the session is used.
If the timeout expires, a :exc:`~zhmcclient.OperationTimeout`
is raised.
This method gives completion of the job priority over strictly
achieving the timeout. This may cause a slightly longer duration of
the method than prescribed by the timeout.
Returns:
:term:`json object` or `None`:
The result of the original asynchronous operation that was
performed by the job, from the ``job-results`` field of the
response body of the "Query Job Status" HMC operation. That result
is a :term:`json object` as described for the asynchronous
operation, or `None` if the operation has no result.
Raises:
:exc:`~zhmcclient.HTTPError`: The job completed in error, or the job
status cannot be retrieved, or the job cannot be deleted.
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ClientAuthError`
:exc:`~zhmcclient.ServerAuthError`
:exc:`~zhmcclient.OperationTimeout`: The timeout expired while
waiting for job completion.
"""
if operation_timeout is None:
operation_timeout = \
self.session.retry_timeout_config.operation_timeout
if operation_timeout > 0:
start_time = time.time()
while True:
try:
job_status, op_result_obj = self.check_for_completion()
except ConnectionError:
HMC_LOGGER.debug("Retrying after ConnectionError while waiting"
" for completion of job %s. This could be "
"because HMC is restarting.", self.uri)
job_status = None
# We give completion of status priority over strictly achieving
# the timeout, so we check status first. This may cause a longer
# duration of the method than prescribed by the timeout.
if job_status == 'complete':
return op_result_obj
if operation_timeout > 0:
current_time = time.time()
if current_time > start_time + operation_timeout:
raise OperationTimeout(
f"Waiting for completion of job {self.uri} timed out "
f"(operation timeout: {operation_timeout} s)",
operation_timeout)
time.sleep(10) # Avoid hot spin loop
[docs]
@logged_api_call
def cancel(self):
"""
Attempt to cancel this job.
This method performs the "Cancel Job" operation on the job.
The specific nature of the job and its current state of execution can
affect the success of the cancellation.
Not all jobs support cancellation; this is described in each zhmcclient
method that can return a job.
If the job exists, supports cancellation and has not yet completed (i.e.
its `status` property is "running"), the cancellation is made pending
for the job and its `status` property is changed to "cancel-pending".
If the operation performed by the job does not support cancellation,
:exc:`~zhmcclient.HTTPError` is raised with status code 404 and reason
code 4.
If the job supports cancellation and exists, but already has a
cancellation request pending (i.e. its `status` property is
"cancel-pending"), :exc:`~zhmcclient.HTTPError` is raised with status
409 and reason code 42.
If the job supports cancellation and exists, but already has ended
(i.e. its `status` property is "complete" or "canceled"),
:exc:`~zhmcclient.HTTPError` is raised with status code 409 and reason
code 41.
If the job supports cancellation but no longer exists,
:exc:`~zhmcclient.HTTPError` is raised with status code 404 and reason
code 1.
Raises:
:exc:`~zhmcclient.HTTPError`: The job cancellation attempt failed.
:exc:`~zhmcclient.ParseError`
:exc:`~zhmcclient.ClientAuthError`
:exc:`~zhmcclient.ServerAuthError`
:exc:`~zhmcclient.ConnectionError`
"""
uri = f'{self.uri}/operations/cancel'
try:
self.session.post(uri)
except Error as exc:
HMC_LOGGER.debug("Request: POST %s failed with %s: %s",
uri, exc.__class__.__name__, exc)
raise
def _text_repr(text, max_len=1000):
"""
Return the input text as a Python string representation (i.e. using repr())
that is limited to a maximum length.
"""
if text is None:
text_repr = 'None'
elif len(text) > max_len:
text_repr = repr(text[0:max_len]) + '...'
else:
text_repr = repr(text)
return text_repr
def _result_object(result):
"""
Return the JSON payload in the HTTP response as a Python dict.
Parameters:
result (requests.Response): HTTP response object.
Raises:
:exc:`~zhmcclient.ParseError`: Error parsing the returned JSON.
"""
content_type = result.headers.get('content-type', None)
if content_type is None or content_type.startswith('application/json'):
# This function is only called when there is content expected.
# Therefore, a response without content will result in a ParseError.
try:
return result.json(object_pairs_hook=OrderedDict)
except ValueError as exc:
new_exc = ParseError(
f"JSON parse error in HTTP response: {exc.args[0]}. "
f"HTTP request: {result.request.method} {result.request.url}. "
f"Response status {result.status_code}. "
f"Response content-type: {content_type!r}. "
f"Content (max.1000, decoded using {result.encoding}): "
f"{_text_repr(result.text, 1000)}")
new_exc.__cause__ = None
raise new_exc # zhmcclient.ParseError
if content_type.startswith('text/html'):
# We are in some error situation. The HMC returns HTML content
# for some 5xx status codes. We try to deal with it somehow,
# but we are not going as far as real HTML parsing.
m = re.search(r'charset=([^;,]+)', content_type)
if m:
encoding = m.group(1) # e.g. RFC "ISO-8859-1"
else:
encoding = 'utf-8'
try:
html_uni = result.content.decode(encoding)
except LookupError:
html_uni = result.content.decode()
# We convert to one line to be regexp-friendly.
html_oneline = html_uni.replace('\r\n', '\\n').replace('\r', '\\n').\
replace('\n', '\\n')
# Check for some well-known errors:
if re.search(r'javax\.servlet\.ServletException: '
r'Web Services are not enabled\.', html_oneline):
html_title = "Console Configuration Error"
html_details = "Web Services API is not enabled on the HMC."
html_reason = HTML_REASON_WEB_SERVICES_DISABLED
else:
m = re.search(
r'<title>([^<]*)</title>.*'
r'<h2>Details:</h2>(.*)(<hr size="1" noshade>)?</body>',
html_oneline)
if m:
html_title = m.group(1)
# Spend a reasonable effort to make the HTML readable:
html_details = m.group(2).replace('<p>', '\\n').\
replace('<br>', '\\n').replace('\\n\\n', '\\n').strip()
else:
html_title = "Console Internal Error"
html_details = f"Response body: {html_uni!r}"
html_reason = HTML_REASON_OTHER
message = f"{html_title}: {html_details}"
# We create a minimal JSON error object (to the extent we use it
# when processing it):
result_obj = {
'http-status': result.status_code,
'reason': html_reason,
'message': message,
'request-uri': result.request.url,
'request-method': result.request.method,
}
return result_obj
if content_type.startswith('application/vnd.ibm-z-zmanager-metrics'):
content_bytes = result.content
assert isinstance(content_bytes, bytes)
return content_bytes.decode('utf-8') # as a unicode object
raise ParseError(
f"Unknown content type in HTTP response: {content_type}. "
f"HTTP request: {result.request.method} {result.request.url}. "
f"Response status {result.status_code}. "
f"Content (max.1000, decoded using {result.encoding}): "
f"{_text_repr(result.text, 1000)}")
def json2dict(json_str):
"""
Convert a JSON string into a dict.
Parameters:
json_str (string): Unicode or binary string in JSON format.
Returns:
dict: JSON string converted to a dict.
Raises:
ValueError: Cannot parse JSON string
"""
json_dict = json.loads(json_str) # May raise ValueError
return json_dict
def dict2json(json_dict):
"""
Convert a dict into a JSON string.
Parameters:
json_dict (dict): The dict.
Returns:
unicode string (py3) or byte string (py2): Dict converted to a JSON
string.
"""
json_str = json.dumps(json_dict)
return json_str