9c061c61c2
This document describes the work required for adding a jsonschema validation layer to the Zun API. Partially-Implements: blueprint api-json-input-validation Change-Id: Id7fecbef3aeb9a208b99c968f4ed4a60897403aa
173 lines
4.6 KiB
ReStructuredText
173 lines
4.6 KiB
ReStructuredText
..
|
|
This work is licensed under a Creative Commons Attribution 3.0 Unported
|
|
License.
|
|
|
|
http://creativecommons.org/licenses/by/3.0/legalcode
|
|
|
|
==============
|
|
API Validation
|
|
==============
|
|
|
|
`bp api-json-input-validation <https://blueprints.launchpad.net/zun/+spec/api-json-input-validation>`_
|
|
|
|
The purpose of this blueprint is to track the progress of validating the
|
|
request bodies sent to the Zun API server, accepting requests
|
|
that fit the resource schema and rejecting requests that do not fit the
|
|
schema. Depending on the content of the request body, the request should
|
|
be accepted or rejected consistently regardless of the resource the request
|
|
is for.
|
|
|
|
Problem Description
|
|
===================
|
|
|
|
Currently Zun validates each type of resource in request body by defining a
|
|
type class for that resource, although such approach is good but is not very
|
|
scalable. It also require conversion of request body to controller object and
|
|
vice versa.
|
|
|
|
Use Case: As an End User, I want to observe consistent API validation and
|
|
values passed to the Zun API server.
|
|
|
|
Proposed Change
|
|
===============
|
|
|
|
One possible way to validate the Zun API is to use jsonschema
|
|
(https://pypi.python.org/pypi/jsonschema). A jsonschema validator object can
|
|
be used to check each resource against an appropriate schema for that
|
|
resource. If the validation passes, the request can follow the existing flow
|
|
of control to the resource manager. If the request body parameters fail the
|
|
validation specified by the resource schema, a validation error will be
|
|
returned from the server.
|
|
|
|
Example:
|
|
"Invalid input for field 'cpu'. The value is 'some invalid cpu value'.
|
|
|
|
We can build in some sort of truncation check if the value of the attribute is
|
|
too long. For example, if someone tries to pass in a 300 character name of
|
|
container we should check for that case and then only return a useful message,
|
|
instead of spamming the logs. Truncating some really long container name might
|
|
not help readability for the user, so return a message to the user with what
|
|
failed validation.
|
|
|
|
Example:
|
|
"Invalid input for field 'name'."
|
|
|
|
Some notes on doing this implementation:
|
|
|
|
* Common parameter types can be leveraged across all Zun resources. An
|
|
example of this would be as follows::
|
|
|
|
from zun.common.validation import parameter_types
|
|
<snip>
|
|
CREATE = {
|
|
'type': 'object',
|
|
'properties': {
|
|
'name': parameter_types.name,
|
|
'image': parameter_types.image,
|
|
'command': parameter_types.command,
|
|
<snip>
|
|
},
|
|
'required': ['image'],
|
|
'additionalProperties': True,
|
|
}
|
|
|
|
* The validation can take place at the controller layer.
|
|
|
|
* When adding a new extension to Zun, the new extension must be proposed
|
|
with its appropriate schema.
|
|
|
|
Alternatives
|
|
------------
|
|
|
|
`Voluptuous <https://github.com/alecthomas/voluptuous>`_ might be another
|
|
option for input validation.
|
|
|
|
Data Model Impact
|
|
-----------------
|
|
|
|
This blueprint shouldn't require a database migration or schema change.
|
|
|
|
REST API Impact
|
|
---------------
|
|
|
|
This blueprint shouldn't affect the existing API.
|
|
|
|
Security Impact
|
|
---------------
|
|
|
|
None
|
|
|
|
Notifications Impact
|
|
--------------------
|
|
|
|
None
|
|
|
|
Other End User Impact
|
|
---------------------
|
|
|
|
None
|
|
|
|
Performance Impact
|
|
------------------
|
|
|
|
Changes required for request validation do not require any locking mechanisms.
|
|
|
|
Other Deployer Impact
|
|
---------------------
|
|
|
|
None
|
|
|
|
Developer Impact
|
|
----------------
|
|
|
|
This will require developers contributing new extensions to Zun to have
|
|
a proper schema representing the extension's API.
|
|
|
|
Implementation
|
|
==============
|
|
|
|
Assignee(s)
|
|
-----------
|
|
|
|
Primary assignee:
|
|
pksingh (Pradeep Kumar Singh <ps4openstack@gmail.com>)
|
|
|
|
Work Items
|
|
----------
|
|
|
|
1. Initial validator implementation, which will contain common validator code
|
|
designed to be shared across all resource controllers validating request
|
|
bodies.
|
|
2. Introduce validation schemas for existing core API resources.
|
|
3. Enforce validation on proposed core API additions and extensions.
|
|
|
|
Dependencies
|
|
============
|
|
|
|
None
|
|
|
|
Testing
|
|
=======
|
|
|
|
Tempest tests can be added as each resource is validated against its schema.
|
|
|
|
Documentation Impact
|
|
====================
|
|
|
|
None
|
|
|
|
References
|
|
==========
|
|
|
|
Useful Links:
|
|
|
|
* [Understanding JSON Schema] (http://spacetelescope.github.io/understanding-json-schema/reference/object.html)
|
|
|
|
* [Nova Validation Examples] (http://git.openstack.org/cgit/openstack/nova/tree/nova/api/validation)
|
|
|
|
* [JSON Schema on PyPI] (https://pypi.python.org/pypi/jsonschema)
|
|
|
|
* [JSON Schema core definitions and terminology] (http://tools.ietf.org/html/draft-zyp-json-schema-04)
|
|
|
|
* [JSON Schema Documentation] (http://json-schema.org/documentation.html)
|