python-openstackclient/openstackclient/common/utils.py

420 lines
14 KiB
Python

# Copyright 2012-2013 OpenStack Foundation
#
# 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.
#
"""Common client utilities"""
import getpass
import logging
import os
import six
import time
from oslo_utils import importutils
from openstackclient.common import exceptions
def find_resource(manager, name_or_id, **kwargs):
"""Helper for the _find_* methods.
:param manager: A client manager class
:param name_or_id: The resource we are trying to find
:param kwargs: To be used in calling .find()
:rtype: The found resource
This method will attempt to find a resource in a variety of ways.
Primarily .get() methods will be called with `name_or_id` as an integer
value, and tried again as a string value.
If both fail, then a .find() is attempted, which is essentially calling
a .list() function with a 'name' query parameter that is set to
`name_or_id`.
Lastly, if any kwargs are passed in, they will be treated as additional
query parameters. This is particularly handy in the case of finding
resources in a domain.
"""
# Try to get entity as integer id
try:
if isinstance(name_or_id, int) or name_or_id.isdigit():
return manager.get(int(name_or_id), **kwargs)
# FIXME(dtroyer): The exception to catch here is dependent on which
# client library the manager passed in belongs to.
# Eventually this should be pulled from a common set
# of client exceptions.
except Exception as ex:
if type(ex).__name__ == 'NotFound':
pass
else:
raise
# Try directly using the passed value
try:
return manager.get(name_or_id, **kwargs)
except Exception:
pass
if len(kwargs) == 0:
kwargs = {}
try:
# Prepare the kwargs for calling find
if 'NAME_ATTR' in manager.resource_class.__dict__:
# novaclient does this for oddball resources
kwargs[manager.resource_class.NAME_ATTR] = name_or_id
else:
kwargs['name'] = name_or_id
except Exception:
pass
# finally try to find entity by name
try:
return manager.find(**kwargs)
# FIXME(dtroyer): The exception to catch here is dependent on which
# client library the manager passed in belongs to.
# Eventually this should be pulled from a common set
# of client exceptions.
except Exception as ex:
if type(ex).__name__ == 'NotFound':
msg = "No %s with a name or ID of '%s' exists." % \
(manager.resource_class.__name__.lower(), name_or_id)
raise exceptions.CommandError(msg)
if type(ex).__name__ == 'NoUniqueMatch':
msg = "More than one %s exists with the name '%s'." % \
(manager.resource_class.__name__.lower(), name_or_id)
raise exceptions.CommandError(msg)
else:
pass
try:
for resource in manager.list():
# short circuit and return the first match
if (resource.get('id') == name_or_id or
resource.get('name') == name_or_id):
return resource
else:
# we found no match, keep going to bomb out
pass
except Exception:
# in case the list fails for some reason
pass
# if we hit here, we've failed, report back this error:
msg = "Could not find resource %s" % name_or_id
raise exceptions.CommandError(msg)
def format_dict(data):
"""Return a formatted string of key value pairs
:param data: a dict
:rtype: a string formatted to key='value'
"""
output = ""
for s in sorted(data):
output = output + s + "='" + six.text_type(data[s]) + "', "
return output[:-2]
def format_list(data, separator=', '):
"""Return a formatted strings
:param data: a list of strings
:param separator: the separator to use between strings (default: ', ')
:rtype: a string formatted based on separator
"""
return separator.join(sorted(data))
def format_list_of_dicts(data):
"""Return a formatted string of key value pairs for each dict
:param data: a list of dicts
:rtype: a string formatted to key='value' with dicts separated by new line
"""
return '\n'.join(format_dict(i) for i in data)
def get_field(item, field):
try:
if isinstance(item, dict):
return item[field]
else:
return getattr(item, field)
except Exception:
msg = "Resource doesn't have field %s" % field
raise exceptions.CommandError(msg)
def get_item_properties(item, fields, mixed_case_fields=[], formatters={}):
"""Return a tuple containing the item properties.
:param item: a single item resource (e.g. Server, Project, etc)
:param fields: tuple of strings with the desired field names
:param mixed_case_fields: tuple of field names to preserve case
:param formatters: dictionary mapping field names to callables
to format the values
"""
row = []
for field in fields:
if field in mixed_case_fields:
field_name = field.replace(' ', '_')
else:
field_name = field.lower().replace(' ', '_')
data = getattr(item, field_name, '')
if field in formatters:
row.append(formatters[field](data))
else:
row.append(data)
return tuple(row)
def get_dict_properties(item, fields, mixed_case_fields=[], formatters={}):
"""Return a tuple containing the item properties.
:param item: a single dict resource
:param fields: tuple of strings with the desired field names
:param mixed_case_fields: tuple of field names to preserve case
:param formatters: dictionary mapping field names to callables
to format the values
"""
row = []
for field in fields:
if field in mixed_case_fields:
field_name = field.replace(' ', '_')
else:
field_name = field.lower().replace(' ', '_')
data = item[field_name] if field_name in item else ''
if field in formatters:
row.append(formatters[field](data))
else:
row.append(data)
return tuple(row)
def sort_items(items, sort_str):
"""Sort items based on sort keys and sort directions given by sort_str.
:param items: a list or generator object of items
:param sort_str: a string defining the sort rules, the format is
'<key1>:[direction1],<key2>:[direction2]...', direction can be 'asc'
for ascending or 'desc' for descending, if direction is not given,
it's ascending by default
:return: sorted items
"""
if not sort_str:
return items
# items may be a generator object, transform it to a list
items = list(items)
sort_keys = sort_str.strip().split(',')
for sort_key in reversed(sort_keys):
reverse = False
if ':' in sort_key:
sort_key, direction = sort_key.split(':', 1)
if not sort_key:
msg = "empty string is not a valid sort key"
raise exceptions.CommandError(msg)
if direction not in ['asc', 'desc']:
if not direction:
direction = "empty string"
msg = ("%s is not a valid sort direction for sort key %s, "
"use asc or desc instead" % (direction, sort_key))
raise exceptions.CommandError(msg)
if direction == 'desc':
reverse = True
items.sort(key=lambda item: get_field(item, sort_key),
reverse=reverse)
return items
def env(*vars, **kwargs):
"""Search for the first defined of possibly many env vars
Returns the first environment variable defined in vars, or
returns the default defined in kwargs.
"""
for v in vars:
value = os.environ.get(v, None)
if value:
return value
return kwargs.get('default', '')
def get_client_class(api_name, version, version_map):
"""Returns the client class for the requested API version
:param api_name: the name of the API, e.g. 'compute', 'image', etc
:param version: the requested API version
:param version_map: a dict of client classes keyed by version
:rtype: a client class for the requested API version
"""
try:
client_path = version_map[str(version)]
except (KeyError, ValueError):
msg = "Invalid %s client version '%s'. must be one of: %s" % (
(api_name, version, ', '.join(version_map.keys())))
raise exceptions.UnsupportedVersion(msg)
return importutils.import_class(client_path)
def wait_for_status(status_f,
res_id,
status_field='status',
success_status=['active'],
error_status=['error'],
sleep_time=5,
callback=None):
"""Wait for status change on a resource during a long-running operation
:param status_f: a status function that takes a single id argument
:param res_id: the resource id to watch
:param status_field: the status attribute in the returned resource object
:param success_status: a list of status strings for successful completion
:param error_status: a list of status strings for error
:param sleep_time: wait this long (seconds)
:param callback: called per sleep cycle, useful to display progress
:rtype: True on success
"""
while True:
res = status_f(res_id)
status = getattr(res, status_field, '').lower()
if status in success_status:
retval = True
break
elif status in error_status:
retval = False
break
if callback:
progress = getattr(res, 'progress', None) or 0
callback(progress)
time.sleep(sleep_time)
return retval
def wait_for_delete(manager,
res_id,
status_field='status',
error_status=['error'],
exception_name=['NotFound'],
sleep_time=5,
timeout=300,
callback=None):
"""Wait for resource deletion
:param manager: the manager from which we can get the resource
:param res_id: the resource id to watch
:param status_field: the status attribute in the returned resource object,
this is used to check for error states while the resource is being
deleted
:param error_status: a list of status strings for error
:param exception_name: a list of exception strings for deleted case
:param sleep_time: wait this long between checks (seconds)
:param timeout: check until this long (seconds)
:param callback: called per sleep cycle, useful to display progress; this
function is passed a progress value during each iteration of the wait
loop
:rtype: True on success, False if the resource has gone to error state or
the timeout has been reached
"""
total_time = 0
while total_time < timeout:
try:
# might not be a bad idea to re-use find_resource here if it was
# a bit more friendly in the exceptions it raised so we could just
# handle a NotFound exception here without parsing the message
res = manager.get(res_id)
except Exception as ex:
if type(ex).__name__ in exception_name:
return True
raise
status = getattr(res, status_field, '').lower()
if status in error_status:
return False
if callback:
progress = getattr(res, 'progress', None) or 0
callback(progress)
time.sleep(sleep_time)
total_time += sleep_time
# if we got this far we've timed out
return False
def get_effective_log_level():
"""Returns the lowest logging level considered by logging handlers
Retrieve and return the smallest log level set among the root
logger's handlers (in case of multiple handlers).
"""
root_log = logging.getLogger()
min_log_lvl = logging.CRITICAL
for handler in root_log.handlers:
min_log_lvl = min(min_log_lvl, handler.level)
return min_log_lvl
def get_password(stdin, prompt=None, confirm=True):
message = prompt or "User Password:"
if hasattr(stdin, 'isatty') and stdin.isatty():
try:
while True:
first_pass = getpass.getpass(message)
if not confirm:
return first_pass
second_pass = getpass.getpass("Repeat " + message)
if first_pass == second_pass:
return first_pass
print("The passwords entered were not the same")
except EOFError: # Ctl-D
raise exceptions.CommandError("Error reading password.")
raise exceptions.CommandError("There was a request to be prompted for a"
" password and a terminal was not detected.")
def read_blob_file_contents(blob_file):
try:
with open(blob_file) as file:
blob = file.read().strip()
return blob
except IOError:
msg = "Error occurred trying to read from file %s"
raise exceptions.CommandError(msg % blob_file)
def build_kwargs_dict(arg_name, value):
"""Return a dictionary containing `arg_name` if `value` is set."""
kwargs = {}
if value:
kwargs[arg_name] = value
return kwargs
def is_ascii(string):
try:
string.decode('ascii')
return True
except UnicodeDecodeError:
return False