Utilities and helper functions.
Bases: nova.utils.LoopingCallBase
A looping call which happens sleeps until the next known event.
The function called should return how long to sleep for before being called again.
Bases: object
Class to wrap another and translate the ClientExceptions raised by its function calls to the actual ones
Bases: nova.utils.LoopingCallBase
A looping call which happens at a fixed interval.
Bases: object
A pluggable backend loaded lazily based on some value.
Bases: exceptions.Exception
Exception to break out and stop a LoopingCall.
The poll-function passed to LoopingCall can raise this exception to break out of the loop normally. This is somewhat analogous to StopIteration.
An optional return-value can be included as the argument to the exception; this return-value will be returned by LoopingCall.wait()
Bases: object
Provides a mechanism to facilitate rolling back a series of actions when an exception is raised.
Rollback a series of actions then re-raise the exception.
Note
(sirp) This should only be called within an exception handler.
Convert a string representation of a bool into a bool value.
Checks that obj is of type cls, and lets PyLint infer types.
Check the length of specified string :param value: the value of the string :param name: the name of the string :param min_length: the min_length of the string :param max_length: the max_length of the string
Convert a value or list into a list of dicts.
delete a file, but ignore file not found error.
Return a dict describing how to change orig to new. The keys correspond to values that have changed; the value will be a list of one or two elements. The first element of the list will be either ‘+’ or ‘-‘, indicating whether the key was updated or deleted; if the key was updated, the list will contain a second element, giving the updated value.
Helper method to execute command with optional retry.
If you add a run_as_root=True command, don’t forget to add the corresponding filter to etc/nova/rootwrap.d !
| Parameters: |
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| Raises: |
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| Returns: | a tuple, (stdout, stderr) from the spawned process, or None if the command fails. |
Open file
see built-in file() documentation for more details
Recursively flatten a nested dictionary.
Generate an Ethernet MAC address.
Generate a random password from the supplied symbol groups.
At least one symbol from each group will be included. Unpredictable results if length is less than the number of symbol groups.
Believed to be reasonably secure (with a reasonable password length!)
Returns a list of items matching the specified path.
Takes an XPath-like expression e.g. prop1/prop2/prop3, and for each item in items, looks up items[prop1][prop2][prop3]. Like XPath, if any of the intermediate results are lists it will treat each list item individually. A ‘None’ in items or any child expressions will be ignored, this function will not throw because of None (anywhere) in items. The returned list will contain no None values.
Returns the IP version of a network (IPv4 or IPv6). Raises AddrFormatError if invalid network.
Get the method at the bottom of a stack of decorators.
Generate a hash for the contents of a file.
Check if a value looks like an int.
Check if the provided string is a valid bool string or not.
Check if the provided ipv4 or ipv6 address is a valid CIDR address or not
Verify that address represents a valid IPv4 address.
Return num bytes from the end of the file, and remaining byte count.
| Parameters: |
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:returns (data, remaining)
This method gives you the most recently completed audit period.
Return a path to a particular device.
>>> make_dev_path('xvdc')
/dev/xvdc
>>> make_dev_path('xvdc', 1)
/dev/xvdc1
Return a dict in which the dictionaries keys are mapped to new keys.
Format a file or block device
| Parameters: |
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If the Flags.monkey_patch set as True, this function patches a decorator for all functions in specified modules. You can set decorators for each modules using CONF.monkey_patch_modules. The format is “Module path:Decorator function”. Example:
‘nova.api.ec2.cloud:nova.openstack.common.notifier.api.notify_decorator’
Parameters of the decorator is as follows. (See nova.openstack.common.notifier.api.notify_decorator)
name - name of the function function - object of the function
Parses the given server_string and returns a list of host and port. If it’s not a combination of host part and port, the port element is a null string. If the input is invalid expression, return a null list.
Return two dicts, one with keys the other with everything else.
Read from a file if it has been modified.
| Parameters: |
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| Returns: | data from file |
Secure helper to read file as root.
Protect code that wants to operate on PATH atomically. Any exception will cause PATH to be removed.
Return a hostname which conforms to RFC-952 and RFC-1123 specs.
Return a dict that only contains a subset of keys.
Temporarily chown a path.
| Params owner_uid: | |
|---|---|
| UID of temporary owner (defaults to current user) | |
Temporarily set the attr on a particular object to a given value then revert when finished.
One use of this is to temporarily set the read_deleted flag on a context object:
- with temporary_mutation(context, read_deleted=”yes”):
- do_something_that_needed_deleted_objects()
Decorator that logs how long a particular function took to execute.
Try to turn a string into a number of bytes. Looks at the last characters of the text to determine what conversion is needed to turn the input text into a byte number.
Supports: B/b, K/k, M/m, G/g, T/t (or the same with b/B on the end)
Local total_seconds implementation for compatibility with python 2.6.
A wrapper around execute() to more easily handle warnings and errors.
Returns an (out, err) tuple of strings containing the output of the command’s stdout and stderr. If ‘err’ is not empty then the command can be considered to have failed.
Try to turn a string into utf-8 if possible.
Code is directly from the utf8 function in http://github.com/facebook/tornado/blob/master/tornado/escape.py
Sends a vpn negotiation packet and returns the server session.
Returns False on a failure. Basic packet structure is below.
Client packet (14 bytes):
0 1 8 9 13
+-+--------+-----+
|x| cli_id |?????|
+-+--------+-----+
x = packet identifier 0x38
cli_id = 64 bit identifier
? = unknown, probably flags/padding
Server packet (26 bytes):
0 1 8 9 13 14 21 2225
+-+--------+-----+--------+----+
|x| srv_id |?????| cli_id |????|
+-+--------+-----+--------+----+
x = packet identifier 0x40
cli_id = 64 bit identifier
? = unknown, probably flags/padding
bit 9 was 1 and the rest were 0 in testing
Walk class hierarchy, yielding most derived classes first.
Escapes a string so it is valid within XML or XHTML.