1 files changed, 133 insertions, 3 deletions

diff --git a/doc/book-enea-nfv-access-platform-guide/doc/container_virtualization.xml b/doc/book-enea-nfv-access-platform-guide/doc/container_virtualization.xml
index 6f74061..c6ce223 100644
--- a/doc/book-enea-nfv-access-platform-guide/doc/container_virtualization.xml
+++ b/doc/book-enea-nfv-access-platform-guide/doc/container_virtualization.xml
@@ -1,8 +1,138 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.0" encoding="ISO-8859-1"?>
 <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
-<chapter condition="hidden" id="workflow">
+<chapter id="container-virtualization">
   <title>Container Virtualization</title>
 
-  <para></para>
+  <section id="docker">
+    <title>Docker</title>
+
+    <para>Docker is an open-source project that automates the deployment of
+    applications inside software containers, by providing an additional layer
+    of abstraction and automation of operating-system-level virtualization on
+    Linux.</para>
+
+    <para>The software container mechanism uses resource isolation features
+    inside the Linux kernel, such as cgroups and kernel namespaces to allow
+    multiple containers to run within a single Linux instance, avoiding the
+    overhead of starting and maintaining virtual machines. </para>
+
+    <para>Containers are lightweight and include everything needed to run
+    themselves: code, runtime, system tools, system libraries and settings.
+    The main advantage provided by containers is that the encapsulated
+    software is isolated from its surroundings. For example, differences
+    between development and staging environments can be kept separate in order
+    to reduce conflicts between teams running different software on the same
+    infrastructure. </para>
+
+    <para>For a better understanding of what Docker is and how it works, the
+    official documentation provided on the Docker website should be consulted:
+    <ulink
+    url="https://docs.docker.com/">https://docs.docker.com/</ulink>.</para>
+
+    <section id="launch-docker-container">
+      <title>Launching a Docker container</title>
+
+      <para>Docker provides a hello-world container which checks whether your
+      system is running the daemon correctly. This container can be launched
+      by simply running:</para>
+
+      <programlisting>&gt;docker run hello-world
+
+Hello from Docker!</programlisting>
+
+      <para>This message shows that your installation appears to be working
+      correctly.</para>
+    </section>
+
+    <section id="run-enfv-guest-image">
+      <title>Run an Enea NFV Access Platform guest image</title>
+
+      <para>Enea NFV Access Platform guest images can run inside Docker as any
+      other container can. Before starting an Enea NFV Access Platform guest
+      image, a root filesystem has to be imported in Docker:</para>
+
+      <programlisting>&gt;docker import enea-linux-virtualization-guest-x86-64.tar.gz el7guest</programlisting>
+
+      <para>To check that the Docker image has been imported successfully,
+      run:</para>
+
+      <programlisting>&gt;docker images</programlisting>
+
+      <para>Finally, start an Enea NFV Access Platform container with
+      <literal>bash</literal> running as the shell, by running:</para>
+
+      <programlisting>&gt;docker run -it el7guest /bin/bash</programlisting>
+    </section>
+
+    <section id="attach-ext-resources-docker-containers">
+      <title>Attach external resources to Docker containers</title>
+
+      <para>Any system resource present on the host machine can be attached or
+      accessed by a Docker container.</para>
+
+      <para>Typically, if a file or folder on the host machine needs to be
+      attached to a container, that container should be launched with the
+      <literal>-v</literal> parameter. For example, to attach the
+      <literal>roots</literal> home folder to a container, the command line
+      for Docker should have the following format:</para>
+
+      <programlisting>&gt;docker run -it -v /home/root:/home/host_root/ el7guest /bin/bash</programlisting>
+
+      <para>To check that folders have been properly passed from the host to
+      the container, create a file in the source folder on the host root
+      filesystem and check for its existence inside the containers destination
+      location.</para>
+
+      <section id="attach-vhost-descriptors">
+        <title>Attach vhost file descriptors</title>
+
+        <para>If OVS is running on the host and vhost file descriptors need to
+        be passed to the container, this can be done by either mapping the
+        folder where all the file descriptors are located or mapping the file
+        descriptor itself:</para>
+
+        <itemizedlist>
+          <listitem>
+            <para>Mapping the folder can be done as exemplified above:</para>
+
+            <programlisting>docker run -it --rm -v /var/run/openvswitch/:/var/run/openvswitch/ el7guest /bin/bash</programlisting>
+          </listitem>
+
+          <listitem>
+            <para>Mapping a file descriptor is done in a similar way, but the
+            <literal>-v</literal> flag needs to point directly to it:</para>
+
+            <programlisting>&gt;docker run -it --rm -v /var/run/openvswitch/vhost-user1 el7guest /bin/bash</programlisting>
+          </listitem>
+        </itemizedlist>
+      </section>
+
+      <section id="attach-hugepages-mount-folders">
+        <title>Attach hugepages mount folders</title>
+
+        <para>Hugepages mount folders can also be accessed by a container
+        similarly to how a plain folder is mapped, as shown in 1.3.</para>
+
+        <para>For example, if the host system has hugepages mounted in the
+        <literal>/mnt/huge</literal> location, a container can also access
+        hugepages by being launched with:</para>
+
+        <programlisting>&gt;docker run -it -v /mnt/huge el7guest /bin/bash</programlisting>
+      </section>
+
+      <section id="access-pci-bus">
+        <title>Access the PCI bus</title>
+
+        <para>If the host machine has multiple SRIOV instances created, a
+        container can access the instances by being given privileged access to
+        the host system. Unlike folders, PCI devices do not have to be mounted
+        explicitly in order to be accessed and will be available to the
+        container if the <literal>--privileged</literal> flag is passed to the
+        command line:</para>
+
+        <programlisting>&gt;docker run --privileged -it el7guest /bin/bash</programlisting>
+      </section>
+    </section>
+  </section>
 </chapter>
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