keystone reports internal error when policy.json is broken

[xingzhou]

if policy.json is broken, when using keystone apis, will return HTTP 500 (internal error).

For better user experience, we need to provide:
1). a better response for use to explain what had happend
and
2). a default policy list to use in case the policy.json is broken.

[Dolph Mathews (dolph)]

If policy.json is "broken" (invalid JSON syntax, for example), I'd fully expect the API to return a generic 500. However, an ERROR log explaining that policy.json could not be parsed would certainly be beneficial.

[Dolph Mathews (dolph)]

Current API response:

{
  "error": {
    "message": "An unexpected error prevented the server from fulfilling your request. Expecting property name: line 2 column 5 (char 6)",
    "code": 500,
    "title": "Internal Server Error"
  }
}

Since it's already doing this, I guess it would make sense to wrap that error with a reference the configured "policy_file".

And for reference, the backtrace: http://paste.openstack.org/raw/38254/

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/34339

[xingzhou (xingzhou)]

as from the community, the reviewers think just return 500 is ok, so won't fix this defect

[Dolph Mathews (dolph)]

The core issue described by the bug is one of user experience, so I think the direction is certainly valid. The response should still be a 500, as well. However, we're not providing adequate feedback to the deployer about what went wrong, and perhaps providing too much information to the API user (who *may* not be the deployer).

[Dolph Mathews (dolph)]

Unassigning due to inactivity.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/51163

[Dolph Mathews (dolph)]

Unassigning due to inactivity.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/131574

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/131574
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=383422f2434414d5d736ebdd9a8b4dcc4e15a288
Submitter: Jenkins
Branch: master

commit 383422f2434414d5d736ebdd9a8b4dcc4e15a288
Author: Lance Bragstad <email address hidden>
Date: Tue Oct 28 20:38:33 2014 +0000

    Provide useful info when parsing policy file

    When parsing the policy.json file we should provide a message that helps
    the user or deployer understand there was an issue with the policy file,
    and that they should make sure the policy.json file is valid JSON.

    Change-Id: I63bdb6d8f03a0510e34b7e10cec25263e7c6c63c
    Closes-Bug: #1177623