openstack/microversion-parse
Code Issues Proposed changes

Allow passing a json_error_formatter to the middleware

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This is so error responses can be formatted according to the rules
of the application.

Change-Id: Ie44399447a349ebc49251dc63c23f56c6423fca6
This commit is contained in:
Chris Dent 2018-03-06 21:19:07 +00:00
parent b5359fcd80
commit f816e324b8
2 changed files with 17 additions and 4 deletions
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6
README.rst
View File

@ -104,6 +104,12 @@ versions_list
It's assumed that any application that is using microversions will have such
a list for its own housekeeping and documentation.
One named parameter is optional:
json_error_formatter
A Webob error formatter that can be used to structure the response when JSON
is expected.
For example::
def app():

15
microversion_parse/middleware.py
View File

@ -37,7 +37,8 @@ class MicroversionMiddleware(object):
Otherwise the application is called.
"""
def __init__(self, application, service_type, versions):
def __init__(self, application, service_type, versions,
json_error_formatter=None):
"""Create the WSGI middleware.
:param application: The application hosting the service.
@ -45,11 +46,14 @@ class MicroversionMiddleware(object):
of the application.
:param versions: An ordered list of legitimate versions for the
application.
:param json_error_formatter: A Webob exception error formatter.
See Webob for details.
"""
self.application = application
self.service_type = service_type
self.microversion_environ = '%s.microversion' % service_type
self.versions = versions
self.json_error_formatter = json_error_formatter
@webob.dec.wsgify
def __call__(self, req):
@ -57,13 +61,16 @@ class MicroversionMiddleware(object):
microversion = microversion_parse.extract_version(
req.headers, self.service_type, self.versions)
# TODO(cdent): These error response are not formatted according to
# api-sig guidelines.
# api-sig guidelines, unless a json_error_formatter is provided
# that can do it. For an example, see the placement service.
except ValueError as exc:
raise webob.exc.HTTPNotAcceptable(
('Invalid microversion: %(error)s') % {'error': exc})
('Invalid microversion: %(error)s') % {'error': exc},
json_formatter=self.json_error_formatter)
except TypeError as exc:
raise webob.exc.HTTPBadRequest(
('Invalid microversion: %(error)s') % {'error': exc})
('Invalid microversion: %(error)s') % {'error': exc},
json_formatter=self.json_error_formatter)
req.environ[self.microversion_environ] = microversion
microversion_header = '%s %s' % (self.service_type, microversion)