Decouple cinder volume for container image storage

[Spyros Trigazis]

In the swarm_atomic and k8s_atomic drivers container images are
stored in a dedicated cinder volume per cluster node. It is proven
that this architecture can be a scalability bottleneck.

When the user doesn't specify docker_volume_size or select 9, the
container images will be stored in the local vm or bm disk.

This architecture can result high performance in vms in SSDs and
improve the scalability of magnum for large clusters.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/391830

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/391830
Committed: https://git.openstack.org/cgit/openstack/magnum/commit/?id=f82749457c0da6879ba5d189a0fcd8d7a7914602
Submitter: Jenkins
Branch: master

commit f82749457c0da6879ba5d189a0fcd8d7a7914602
Author: Spyros Trigazis <email address hidden>
Date: Fri Sep 30 15:10:52 2016 +0200

    Make cinder volume optional

    In the swarm_atomic and k8s_atomic drivers container images are
    stored in a dedicated cinder volume per cluster node. It is
    proven that this architecture can be a scalability bottleneck.

    Make the use of cinder volumes for container images and opt-in
    option. If docker-volume-size is not specified no cinder
    volumes will be created. Before, if docker-volume-size wasn't
    specified the default value was 25.

    To use cinder volumes for container storage the user will
    interact with magnum as before, (meaning the valid values are
    integers starting from 1).

    Closes-Bug: #1638006
    Change-Id: I3394c62a43bbf950b7cf0b86a71b1d9b0481d68f

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/magnum 4.0.0 release.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/newton
Review: https://review.openstack.org/435805

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/435805
Committed: https://git.openstack.org/cgit/openstack/magnum/commit/?id=73212dbe39fd3e8b3a57dfac82a441ef1ab862c4
Submitter: Jenkins
Branch: stable/newton

commit 73212dbe39fd3e8b3a57dfac82a441ef1ab862c4
Author: Spyros Trigazis <email address hidden>
Date: Fri Sep 30 15:10:52 2016 +0200

    Make cinder volume optional

    The purpose of this patch is primarily to unblock the
    stable/newton gate and secondarily fix the performance issues
    faced with large clusters, where Magnum creates a volume per
    node.

    In the swarm_atomic and k8s_atomic drivers container images are
    stored in a dedicated cinder volume per cluster node. It is
    proven that this architecture can be a scalability bottleneck.

    Make the use of cinder volumes for container images and opt-in
    option. If docker-volume-size is not specified no cinder
    volumes will be created. Before, if docker-volume-size wasn't
    specified the default value was 25.

    To use cinder volumes for container storage the user will
    interact with magnum as before, (meaning the valid values are
    integers starting from 1).

    Backport: I3394c62a43bbf950b7cf0b86a71b1d9b0481d68f
    Conflicts:
    * magnum/drivers/common/swarm_fedora_template_def.py
      Edit magnum/drivers/swarm_fedora_atomic_v1/template_def.py
      instead.
    * magnum/tests/unit/conductor/handlers/test_k8s_cluster_conductor.py
      Remove invalid unit test for docker_volume_size.
      Fix unit test which references the driver class

    Additionally, remove the use of cinder volumes in functioanal tests.
    2nd Backport: Ia3b14603c5fc516b00c862c8b9257e0fd23d4b9e

    Remove service from manager class for tempest.
    3rd Backport: I67f79efd2049c05d36ea56691b664417ed358fd8

    Closes-Bug: #1638006
    Related-Bug: #1422831

    Change-Id: I219f02dc1861bd4b6b9c59ecc6af448d09004f18

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/magnum 3.2.0 release.