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The old ramdisk is deprecated, so we should not really default to it. Also this guide makes an assumption that agent_* and pxe_* drivers can't be used together, which is no longer the case, as IPA handles both. Consolidate the example local.conf into one enabling both pxe_* and agent_* drivers with IPA and create a separate page for explaining difference between these two. Co-Authored-By: Lilia Sampaio <liliars@lsd.ufcg.edu.br> Change-Id: Ifeed7bf9128281b79d425f7c5dbb3d8c39e7fb68
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1.7 KiB
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50 lines
1.7 KiB
ReStructuredText
.. _IPA:
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===================
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Ironic Python Agent
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===================
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Overview
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========
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*Ironic Python Agent* (also often called *IPA* or just *agent*) is a
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Python-based agent which handles *ironic* bare metal nodes in a
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variety of actions such as inspect, configure, clean and deploy images.
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IPA is distributed over nodes and runs, inside of a ramdisk, the
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process of booting this ramdisk on the node.
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For more information see the `ironic-python-agent documentation
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<http://docs.openstack.org/developer/ironic-python-agent/>`_.
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Drivers
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=======
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Starting with the Kilo release all drivers (except for fake ones) are using
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IPA for deployment. There are two types of them, which can be distinguished
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by prefix:
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* For drivers with ``pxe_`` or ``iscsi_`` prefix IPA exposes the root hard
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drive as an iSCSI share and calls back to the ironic conductor. The
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conductor mounts the share and copies an image there. It then signals back
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to IPA for post-installation actions like setting up a bootloader for local
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boot support.
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* For drivers with ``agent_`` prefix the conductor prepares a swift temporary
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URL for an image. IPA then handles the whole deployment process:
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downloading an image from swift, putting it on the machine and doing any
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post-deploy actions.
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Which one to choose depends on your environment. iSCSI-based drivers put
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higher load on conductors, agent-based drivers currently require the whole
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image to fit in the node's memory.
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.. todo: other differences?
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.. todo: explain configuring swift for temporary URL's
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Requirements
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~~~~~~~~~~~~
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Using IPA requires it to be present and configured on the deploy ramdisk, see
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:ref:`BuildingDeployRamdisk` for details.
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