Middleware for swift can not get correct response

[Che-Wei Hu]

Hi, all:

After adding ceilometer middleware to the swift proxy, I can not get correct response anymore.

For example:
Before adding ceilometer middleware: I can get the correct container list.
After adding ceilometer middleware: I only got empty reply from server.

I am a beginner for studying wsgi and openstack.

Could any one else help to provide suggestions for this issue?

Thanks a lot.

[Che-Wei Hu (tethu0822)]

Hi, all:

I found that I can get correct response from swift proxy if I do the following modification for ceilometer/objectstore/swift_middleware.py:

class CeilometerMiddleware(object):
    ...
    def __call__(self, env, start_response):
        ...

        def iter_response(iterable):
            if start_response_args[0]:
                start_response(*start_response_args[0])
            """
            bytes_sent = 0
            try:
                for chunk in iterable:
                    if chunk:
                        bytes_sent += len(chunk)
                    yield chunk
            finally:
                self.publish_sample(env,
                                    input_proxy.bytes_received,
                                    bytes_sent)
            """
            return iterable

        try:
            iterable = self.app(env, my_start_response)
        except Exception:
            self.publish_sample(env, input_proxy.bytes_received, 0)
            raise
        else:
            return iter_response(iterable)

I have no idea why the python for loop makes the response become empty.
Could any one else help to check this issue?

Thanks a lot!

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/46048

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/46049

[Che-Wei Hu (tethu0822)]

Hi, Mehdi Abaakouk:

Thanks for your reply and help.

I tried the patch and I got the exception for the publishing fail.

But I did the following modification I can get correct response from swift proxy:

class CeilometerMiddleware(object):
    ...
    def __call__(self, env, start_response):
        ...

        def iter_response(iterable):
            if start_response_args[0]:
                start_response(*start_response_args[0])

            bytes_sent = 0
            try:
                """
                for chunk in iterable:
                    if chunk:
                        bytes_sent += len(chunk)
                    yield chunk
                """
                return iterable
            finally:
                self.publish_sample(env,
                                                      input_proxy.bytes_received,
                                                      bytes_sent)

        try:
            iterable = self.app(env, my_start_response)
        except Exception:
            self.publish_sample(env, input_proxy.bytes_received, 0)
            raise
        else:
            return iter_response(iterable)

I think they are different issues.

[Che-Wei Hu (tethu0822)]

Hi, Mehdi Abaakouk:

Sorry! There is a typo in my test code.

Therefore, the empty response is caused by the failing publish.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/46048
Committed: http://github.com/openstack/ceilometer/commit/e52e5070b3e0fb8c71e806eda036631e25628800
Submitter: Jenkins
Branch: master

commit e52e5070b3e0fb8c71e806eda036631e25628800
Author: Mehdi Abaakouk <email address hidden>
Date: Wed Sep 11 11:07:30 2013 +0200

    Don't publish samples if resource_id in missing

    In swift API, the user can call uri without the resource_id.
    This patch skip the samples publishing instead of raising the
    exception:

    Traceback (most recent call last):
    File "ceilometer/objectstore/swift_middleware.py", line 109, in iter_response
        bytes_sent)
    File "ceilometer/objectstore/swift_middleware.py", line 160, in publish_sample
        resource_id=account.partition('AUTH_')[2],
    AttributeError: 'NoneType' object has no attribute 'partition'

    It print the exception of the samples publishing failure instead of
    raising a exception to never break the swift API.

    Fixes bug #1223259

    Change-Id: I5d90fa620c8f8ea82e86524b9703049257ca0345

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/grizzly
Review: https://review.openstack.org/51633

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/51633
Committed: http://github.com/openstack/ceilometer/commit/5f3fe99ba85f5b56b826c1f458af3d129531cca1
Submitter: Jenkins
Branch: stable/grizzly

commit 5f3fe99ba85f5b56b826c1f458af3d129531cca1
Author: Mehdi Abaakouk <email address hidden>
Date: Wed Sep 11 11:07:30 2013 +0200

    Don't publish samples if resource_id in missing

    In swift API, the user can call uri without the resource_id.
    This patch skip the samples publishing instead of raising the
    exception:

    Traceback (most recent call last):
    File "ceilometer/objectstore/swift_middleware.py", line 109, in iter_response
        bytes_sent)
    File "ceilometer/objectstore/swift_middleware.py", line 160, in publish_sample
        resource_id=account.partition('AUTH_')[2],
    AttributeError: 'NoneType' object has no attribute 'partition'

    It print the exception of the samples publishing failure instead of
    raising a exception to never break the swift API.

    Fixes bug #1223259

    Change-Id: I5d90fa620c8f8ea82e86524b9703049257ca0345
    (cherry picked from commit e52e5070b3e0fb8c71e806eda036631e25628800)