[RFE] HTTP(S) proxy support for agent images downloading

[Vladyslav Drok]

Currently Ironic Python Agent (IPA) is able to download images via direct
HTTP(S) links, but it does not support proxy configuration. If IPA will support proxy configuration for image downloading user can place caching proxies in the same physical network segments as nodes for reducing overall network traffic and deploying time.

[Ruby Loo (rloo)]

Spec has been approved and is available at http://specs.openstack.org/openstack/ironic-specs/specs/approved/agent-image-proxy.html.

Copying this from the old BP (https://blueprints.launchpad.net/ironic/+spec/agent-image-proxy):

Gerrit topic: https://review.openstack.org/#q,topic:bp/agent-image-proxy,n,z

Addressed by: https://review.openstack.org/225181
    Proxy configuration for agent images downloading

Addressed by: https://review.openstack.org/235493
    Add support for downloading images via proxy in agent driver

Addressed by: https://review.openstack.org/245864
    add "unreleased" release notes page

Addressed by: https://review.openstack.org/250878
    Add documentation for proxies usage with IPA

Addressed by: https://review.openstack.org/254295
    Add ability to cache swift temporary URLs

Addressed by: https://review.openstack.org/254296
    Add proxy related parameters to agent driver

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/254295
Committed: https://git.openstack.org/cgit/openstack/ironic/commit/?id=60aad944976c201983871a862a325f68aa82aa0a
Submitter: Jenkins
Branch: master

commit 60aad944976c201983871a862a325f68aa82aa0a
Author: Vladyslav Drok <email address hidden>
Date: Mon Dec 7 18:23:59 2015 +0200

    Add ability to cache swift temporary URLs

    Caching of swift temporary is only useful for ironic python agent in
    case of using proxies to download instance image.

    This change adds the following:
    - caching of temp URLs, so that proxy server does not invalidate the
      cached image for every deployment.
    - [glance]swift_temp_url_expected_download_start_delay option, so
      that it is not possible to set swift_temp_url_duration less than
      the value specified. This option is also used to determine if
      cached temp URL will be still valid when agent ramdisk starts up.
      To preserve current behavior, this value is set to 0.

    Partial-bug: #1526222

    Change-Id: If79bc0067db92c8917a15a0989143a1133ad4519

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/254296
Committed: https://git.openstack.org/cgit/openstack/ironic/commit/?id=0ed100d6f42c62eab91c57307149ce68f70e6f3c
Submitter: Jenkins
Branch: master

commit 0ed100d6f42c62eab91c57307149ce68f70e6f3c
Author: Vladyslav Drok <email address hidden>
Date: Mon Dec 7 18:34:42 2015 +0200

    Add proxy related parameters to agent driver

    This change adds image_http_proxy, image_https_proxy, image_no_proxy
    parameters to a node's driver_info for use by the agent driver. If set,
    they will be passed to ironic python agent ramdisk and used during
    image download.

    Also this change updates the unit test
    TestAgentVendor.test_continue_deploy_image_source_is_url() as it was was
    incorrect.

    Partial-bug: #1526222

    Change-Id: I7890f761f4adbe768f76831ef5b48b691a70b2d1

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/250878
Committed: https://git.openstack.org/cgit/openstack/ironic/commit/?id=26922806ac3931b3ddd9652a1df807035e9888a1
Submitter: Jenkins
Branch: master

commit 26922806ac3931b3ddd9652a1df807035e9888a1
Author: Vladyslav Drok <email address hidden>
Date: Fri Nov 27 18:15:18 2015 +0200

    Add documentation for proxies usage with IPA

    This change adds documentation on setting proxy properties that will
    be used by IPA ramdisk to download a disk image.

    Closes-bug: #1526222

    Change-Id: Ib640da7304e8a5779e74e1f15898229b6f772b11