42 lines
2.6 KiB
XML
42 lines
2.6 KiB
XML
<?xml version="1.0" encoding="utf-8"?>
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<section xmlns="http://docbook.org/ns/docbook"
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xmlns:xi="http://www.w3.org/2001/XInclude"
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xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0"
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xml:id="docker">
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<title>Docker Driver</title>
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<para>The Docker driver is a hypervisor driver for OpenStack Compute,
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introduced with the Havana release. Docker is an open-source engine which
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automates the deployment of applications as highly portable, self-sufficient
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containers which are independent of hardware, language, framework, packaging
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system and hosting provider. Docker extends LXC with a high level API
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providing a lightweight virtualization solution that runs processes in
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isolation. It provides a way to automate software deployment in a secure and
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repeatable environment. A standard container in Docker contains a software
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component along with all of its dependencies - binaries, libraries,
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configuration files, scripts, virtualenvs, jars, gems and tarballs. Docker
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can be run on any x86_64 Linux kernel that supports cgroups and aufs. Docker
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is a way of managing LXC containers on a single machine. However used behind
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OpenStack Compute makes Docker much more powerful since it’s then possible
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to manage several hosts which will then manage hundreds of containers. The
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current Docker project aims for full OpenStack compatibility. Containers
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don't aim to be a replacement for VMs, they are just complementary in the
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sense that they are better for specific use cases. Compute's support for VMs
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is currently advanced thanks to the variety of hypervisors running VMs.
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However it's not the case for containers even though libvirt/LXC is a good
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starting point. Docker aims to go the second level of integration.</para>
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<note><para>
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Some OpenStack Compute features are not implemented by
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the docker driver. See the <link
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xlink:href="http://wiki.openstack.org/HypervisorSupportMatrix">
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hypervisor support matrix</link> for details.
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</para></note>
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<para>To enable Docker, ensure the following options are set in
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<filename>/etc/nova/nova.conf</filename> on all hosts running the
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<systemitem class="service">nova-compute</systemitem> service.
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<programlisting language="ini">compute_driver=docker.DockerDriver</programlisting></para>
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<para>Glance also needs to be configured to support the Docker container format, in
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<filename>/etc/glance-api.conf</filename>:
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<programlisting language="ini">container_formats = ami,ari,aki,bare,ovf,docker</programlisting></para>
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<xi:include href="tables/nova-docker.xml"/>
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</section>
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