Can't use instance credentials for describe_stack_resource

[Steve Baker]

There are 2 issues preventing stack user credentials from being used to call describe_stack_resource (heat resource-metadata)

* 1. _authorize_stack_user only looks for ec2Credentials in the context, instead of cnxt.user_id
* 2. The context has no user_id set, thanks to the context middleware only setting the user_id if the username is also set

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/84047

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/84047
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=57f508908346fdfd3d2e3e6a0af107411a58e245
Submitter: Jenkins
Branch: master

commit 57f508908346fdfd3d2e3e6a0af107411a58e245
Author: Steve Baker <email address hidden>
Date: Mon Apr 7 16:56:13 2014 +1200

    Allow for stack users in _authorize_stack_user

    This change allows stack user credentials to be used to call
    describe_stack_resource (heat resource-metadata)

    It makes the following changes:
    * _authorize_stack_user first attempts authorize with
      stack.access_allowed using the context user_id before falling back
      to looking for ec2 credentials
    * context middleware sets the user_id on the context even when the
      username is not specified

    This change also adds missing test coverage to ContextMiddleware

    Change-Id: Idb655e403ba11a3144dacf34eba0feb59ab8d911
    Closes-Bug: #1299982

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: milestone-proposed
Review: https://review.openstack.org/85898

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/85898
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=b3942fd443a197fec9fb7e3a9ebdf08655159f06
Submitter: Jenkins
Branch: milestone-proposed

commit b3942fd443a197fec9fb7e3a9ebdf08655159f06
Author: Steve Baker <email address hidden>
Date: Mon Apr 7 16:56:13 2014 +1200

    Allow for stack users in _authorize_stack_user

    This change allows stack user credentials to be used to call
    describe_stack_resource (heat resource-metadata)

    It makes the following changes:
    * _authorize_stack_user first attempts authorize with
      stack.access_allowed using the context user_id before falling back
      to looking for ec2 credentials
    * context middleware sets the user_id on the context even when the
      username is not specified

    This change also adds missing test coverage to ContextMiddleware

    Change-Id: Idb655e403ba11a3144dacf34eba0feb59ab8d911
    Closes-Bug: #1299982