<?xml version="1.0" encoding="UTF-8"?>
<chapter annotations="slide" version="5.1" xml:id="sdiDocker_chap"
xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:xila="http://www.w3.org/2001/XInclude/local-attributes"
xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:trans="http://docbook.org/ns/transclusion"
xmlns:svg="http://www.w3.org/2000/svg"
xmlns:m="http://www.w3.org/1998/Math/MathML"
xmlns:html="http://www.w3.org/1999/xhtml"
xmlns:db="http://docbook.org/ns/docbook">
<title>Docker</title>
<section xml:id="sdiDocker_sect_introduction">
<title>Introduction</title>
<figure xml:id="sdiDocker_figInstall">
<title>Installation</title>
<itemizedlist>
<listitem>
<para><uri
xlink:href="https://docs.docker.com/install">https://docs.docker.com/install</uri></para>
</listitem>
<listitem>
<para><link
xlink:href="https://github.com/wsargent/docker-cheat-sheet">Docker
Cheat Sheet</link></para>
</listitem>
</itemizedlist>
</figure>
<figure xml:id="sdiDocker_Hub">
<title>Docker hub</title>
<para>Repository hosting publicly available Docker images:</para>
<para><uri
xlink:href="https://hub.docker.com/explore">https://hub.docker.com/explore</uri></para>
</figure>
<section xml:id="sdiDocker_manageImages_sect">
<title>Managing images</title>
<figure xml:id="sdiDocker_figSearchImages">
<title>Search images</title>
<screen>> <link
xlink:href="https://docs.docker.com/engine/reference/commandline/search">docker search</link> nextcloud
NAME DESCRIPTION <link
xlink:href="https://docs.docker.com/docker-hub/repos/#stars">STARS</link> <link
xlink:href="https://docs.docker.com/docker-hub/official_repos">OFFICIAL</link> <link
xlink:href="https://docs.docker.com/docker-cloud/builds/automated-build">AUTOMATED</link>
nextcloud A safe home … 424 [OK]
linuxserver/nextcloud A Nextcloud … 56
greyltc/nextcloud Nextcloud: … 34 [OK]
wonderfall/nextcloud All-in-one … 27 [OK]
rootlogin/nextcloud Nextcloud … 17 [OK]
lsioarmhf/nextcloud ARMHF based … 8
ownyourbits/nextcloudpi NextCloud ARM … 7
...</screen>
</figure>
<figure xml:id="sdiDocker_figPullImage">
<title>Pull image using <xref linkend="glo_CLI"/></title>
<screen>> <link
xlink:href="https://docs.docker.com/engine/reference/commandline/image_pull">docker image pull</link> alpine
Using default tag: latest
latest: Pulling from library/alpine
<emphasis role="red">ff3a5c916c92</emphasis>: Pull complete
Digest: sha256:7df6db5aa61ae9480f52f0b3a06a140ab98d427f86d8d5de0bedab9b8df6b1c0
Status: Downloaded newer image for alpine:latest</screen>
</figure>
<figure xml:id="sdiDocker_figPullNextcloudImage">
<title>Pull <productname>Nextcloud</productname> image</title>
<screen>> <link
xlink:href="https://docs.docker.com/engine/reference/commandline/pull">docker image pull</link> <emphasis
role="bold">wonderfall/nextcloud</emphasis> <co
linkends="sdiDocker_figPullNextcloudImage-1"
xml:id="sdiDocker_figPullNextcloudImage-1-co"/>
Using default tag: latest <co linkends="sdiDocker_figPullNextcloudImage-2"
xml:id="sdiDocker_figPullNextcloudImage-2-co"/>
latest: Pulling from wonderfall/nextcloud
<emphasis role="red">ff3a5c916c92</emphasis>: Already exists <co
linkends="sdiDocker_figPullNextcloudImage-3"
xml:id="sdiDocker_figPullNextcloudImage-3-co"/>
a542d4c3cffb: Pull complete <co linkends="sdiDocker_figPullNextcloudImage-4"
xml:id="sdiDocker_figPullNextcloudImage-4-co"/>
83001cc0bea0: Pull complete
41a33c66b2c1: Pull complete
a70bf67726f3: Pull complete
fea90b3d29ac: Pull complete
Digest: sha256:472c5c7...2ca20cca45 <co
linkends="sdiDocker_figPullNextcloudImage-5"
xml:id="sdiDocker_figPullNextcloudImage-5-co"/>
Status: Downloaded newer image for wonderfall/nextcloud:latest</screen>
</figure>
<calloutlist>
<callout arearefs="sdiDocker_figPullNextcloudImage-1-co"
xml:id="sdiDocker_figPullNextcloudImage-1">
<para>Get docker image from remote server.</para>
</callout>
<callout arearefs="sdiDocker_figPullNextcloudImage-2-co"
xml:id="sdiDocker_figPullNextcloudImage-2">
<para>Version defaults to «latest»: Subject to be overridden.</para>
</callout>
<callout arearefs="sdiDocker_figPullNextcloudImage-3-co"
xml:id="sdiDocker_figPullNextcloudImage-3">
<para>Reference to existing <link
linkend="sdiDocker_figPullImage">«alpine» layer</link>.</para>
</callout>
<callout arearefs="sdiDocker_figPullNextcloudImage-4-co"
xml:id="sdiDocker_figPullNextcloudImage-4">
<para>Layer downloads.</para>
</callout>
<callout arearefs="sdiDocker_figPullNextcloudImage-5-co"
xml:id="sdiDocker_figPullNextcloudImage-5">
<para>Hash value allowing for image verification.</para>
</callout>
</calloutlist>
<figure xml:id="sdiDocker_figNextcloudFromAlpine">
<title><productname>Nextcloud</productname> based on
<productname>Alpine</productname></title>
<mediaobject>
<imageobject>
<imagedata fileref="Ref/Docker/layer.multi.svg"/>
</imageobject>
</mediaobject>
</figure>
<figure xml:id="sdiDocker_inspectImage_fig">
<title><link
xlink:href="http://www.googlinux.com/list-all-tags-of-docker-image/index.html">Inspect
image</link></title>
<screen>> docker image inspect dac77467ddcc
[
{
"Id": "sha256:dac77467ddccc2287d99558245bd34707...",
"RepoTags": [
"nextcloud:13.0.4"
],
"RepoDigests": [
"nextcloud@sha256:fb3e77f19b21364925e8f02..."
],
...</screen>
</figure>
<figure xml:id="sdiDocker_figSearchImageTags">
<title><link
xlink:href="http://www.googlinux.com/list-all-tags-of-docker-image/index.html">Search
an image's tags</link></title>
<screen>> curl 'https://registry.hub.docker.com/v2/repositories/library/<emphasis
role="red">nextcloud</emphasis>/tags/'|\
jq '."results"[]["name"]' <emphasis role="red"># requires «aptitude install curl jq»</emphasis>
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 11856 0 11856 0 0 11856 0 --:--:-- --:--:-- --:--:-- 20371
"fpm"
"production"
"stable"
"latest"
"13"
"13.0"
"13.0.2"
"production-apache"
"stable-apache"
"apache"</screen>
</figure>
<figure xml:id="sdiDocker_figNextcloudImageByVersion">
<title><productname>Nextcloud</productname> image by version</title>
<screen>> <link
xlink:href="https://docs.docker.com/engine/reference/commandline/pull">docker image pull</link> nextcloud:13.0.4
13.0.4: Pulling from library/nextcloud
3d77ce4481b1: Pull complete
32bfdb6043a8: Pull complete
028453741593: Pull complete
f93d7bd342a3: Pull complete
4a2fac611953: Pull complete
87fdfc7d0f94: Pull complete
Digest: sha256:<emphasis role="red">fb3e77f19b21364925e8f02d6e5ad3a1</emphasis> ...
Status: Downloaded newer image for <emphasis role="red">nextcloud:13.0.4</emphasis></screen>
</figure>
<figure xml:id="sdiDocker_figListImages">
<title>List images by <xref linkend="glo_CLI"/></title>
<screen>> <link
xlink:href="https://docs.docker.com/engine/reference/commandline/image">docker image ls</link>
REPOSITORY TAG IMAGE ID CREATED SIZE
nextcloud 13.0.4 dac77467ddcc 3 days ago 544MB
wonderfall/nextcloud latest 57e1fb51b334 2 months ago 328MB
alpine latest 3fd9065eaf02 4 months ago 4.15MB</screen>
</figure>
<figure xml:id="sdiDocker_figNextcloudImageLatest">
<title><productname>Nextcloud</productname> latest image</title>
<screen>> <link
xlink:href="https://docs.docker.com/engine/reference/commandline/pull">docker image pull</link> nextcloud
Using default tag: latest
latest: Pulling from library/nextcloud <co
linkends="sdiDocker_figNextcloudImageByVersion-1"
xml:id="sdiDocker_figNextcloudImageByVersion-1-co"/>
Digest: sha256:<emphasis role="red">fb3e77f19b21364925e8f02d6e5ad3a1</emphasis> ... <co
linkends="sdiDocker_figNextcloudImageByVersion-2"
xml:id="sdiDocker_figNextcloudImageByVersion-2-co"/>
Status: Downloaded newer image for <emphasis role="red">nextcloud:latest</emphasis></screen>
</figure>
<calloutlist>
<callout arearefs="sdiDocker_figNextcloudImageByVersion-1-co"
xml:id="sdiDocker_figNextcloudImageByVersion-1">
<para>No «<link
xlink:href="https://docs.docker.com/engine/reference/commandline/pull/#examples">Pull
complete</link>» messages, image is alias of
<code>nextcloud:13.0.4</code>.</para>
</callout>
<callout arearefs="sdiDocker_figNextcloudImageByVersion-2-co"
xml:id="sdiDocker_figNextcloudImageByVersion-2">
<para>Digest value identical to <xref
linkend="sdiDocker_figNextcloudImageByVersion"/>.</para>
</callout>
</calloutlist>
<figure xml:id="sdiDocker_figListNextcloudImages">
<title>Duplicate <productname>Nextcloud</productname> images</title>
<screen>> docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
nextcloud 13.0.4 <emphasis role="red">dac77467ddcc</emphasis> 4 days ago <emphasis
role="red">544MB</emphasis>
nextcloud latest <emphasis role="red">dac77467ddcc</emphasis> 4 days ago <emphasis
role="red">544MB</emphasis>
...</screen>
</figure>
<figure xml:id="sdiDocker_figCompareMavenArtifacts">
<title>Maven ringing a bell?</title>
<programlisting language="xml"><dependency>
<groupId><emphasis role="red">junit</emphasis></groupId> <!-- <emphasis
role="red">wonderfall</emphasis> -->
<artifactId><emphasis role="red">junit</emphasis></artifactId> <!-- <emphasis
role="red">nextcloud</emphasis> -->
<version><emphasis role="red">4.12</emphasis></version> <!-- <emphasis
role="red">13.0.4</emphasis> -->
</dependency></programlisting>
</figure>
<figure xml:id="sdiDocker_figUntagImage_fig">
<title>Un tag image by version</title>
<screen>> docker image rm nextcloud:latest
Untagged: nextcloud:latest
> docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
nextcloud 13.0.4 dac77467ddcc 4 days ago 544MB
...</screen>
</figure>
<figure xml:id="sdiDocker_figRemoveImage_fig">
<title>Remove image by version</title>
<screen>> docker image rm nextcloud:13.0.2
Untagged: nextcloud:latest
Untagged: nextcloud@sha256:c693921e69cb89cd0bee7c014280159df647e5ba87f54c895650156d973df035
Deleted: sha256:10ae267ddcf25bfe5cc059685d3d005bcfe7229b44c3a6f93e0a07795d33b5b2
Deleted: sha256:1c271f4f2f19a222cd116c771b02294c5dd596fa8a0366559061f83a0de8de3f
...
Deleted: sha256:2c833f307fd8f18a378b71d3c43c575fabdb88955a2198662938ac2a08a99928</screen>
</figure>
</section>
<section xml:id="sdiDocker_runningContainer_sect">
<title>Running container</title>
<figure xml:id="sdiDocker_fig_startNexctcloud">
<title>Starting <productname>Nextcloud</productname> container</title>
<screen>> docker run -d -p 8080:80 --name nc13 nextcloud
517e3dba488763eb615f2c68d417e1b7fb3a9ce5bb4a5ffc346dcb86c00d13d2</screen>
</figure>
<figure xml:id="sdiDocker_figListContainer">
<title>List running containers</title>
<screen>> docker ps -a <emphasis role="red"># show stopped containers as well</emphasis>
CONTAINER ID IMAGE COMMAND ... PORTS NAMES
517e3dba4887 nextcloud "/entrypoint.sh apac…" ... 0.0.0.0:8080->80/tcp <emphasis
role="red">nc13</emphasis></screen>
</figure>
<figure xml:id="sdiDocker_enterRunningContainer">
<title>Enter running container</title>
<screen>> docker exec -it nextcloud_db_1 /bin/bash
# ls -al
total 84
drwxr-xr-x 1 root root 4096 Jun 20 09:28 .
drwxr-xr-x 1 root root 4096 Jun 20 09:28 ..
-rwxr-xr-x 1 root root 0 Jun 20 09:28 .dockerenv
drwxr-xr-x 1 root root 4096 May 25 20:20 bin
drwxr-xr-x 2 root root 4096 Nov 19 2017 boot
drwxr-xr-x 5 root root 340 Jun 20 09:28 dev
drwxr-xr-x 2 root root 4096 Apr 30 15:37 docker-entrypoint-initdb.d
lrwxrwxrwx 1 root root 34 May 25 20:20 docker-entrypoint.sh -> usr/local/bin/docker-entrypoint.sh
...</screen>
</figure>
<figure xml:id="sdiDocker_figKillProcess">
<title>Remove container</title>
<screen>> docker rm <emphasis role="red">nc13</emphasis>
nc13</screen>
<screen>> docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS ... NAMES</screen>
</figure>
</section>
<section xml:id="sdiDocker_volumes_sect">
<title>Volumes</title>
<figure xml:id="sdiDocker_listVolumes">
<title>List volumes</title>
<informaltable border="0">
<tr>
<td valign="top"><screen>> docker volume ls
DRIVER VOLUME NAME
local nextcloud_db
local nextcloud_nextcloud</screen></td>
<td valign="top"><screen># ls -al /var/lib/docker/volumes
total 40
drwx------ 4 root root 4096 Jun 20 11:13 .
drwx--x--x 14 root root 4096 Jun 20 09:40 ..
-rw------- 1 root root 32768 Jun 20 11:13 metadata.db
drwxr-xr-x 3 root root 4096 Jun 20 11:13 nextcloud_db
drwxr-xr-x 3 root root 4096 Jun 20 11:13 nextcloud_nextcloud</screen></td>
</tr>
</informaltable>
</figure>
<figure xml:id="sdiDocker_listOrphaneVolumes">
<title>List orphaned volumes</title>
<screen>> docker volume ls <emphasis role="red">-f dangling=true</emphasis>
DRIVER VOLUME NAME
local nextcloud_db
local nextcloud_nextcloud</screen>
</figure>
<figure xml:id="sdiDocker_removeVolume">
<title>Remove volumes</title>
<screen>> docker volume rm nextcloud_db nextcloud_nextcloud
nextcloud_db
nextcloud_nextcloud
</screen>
</figure>
</section>
</section>
<section xml:id="sdiDocker_sect_exercises">
<title>Exercises</title>
<para>In this exercise you are about to replace your package based
<productname>Nextcloud</productname> installation by a
<productname>Docker</productname> container based on an already existing
image. The image is being described at:</para>
<blockquote>
<para><uri
xlink:href="https://github.com/nextcloud/docker">https://github.com/nextcloud/docker</uri></para>
</blockquote>
<section xml:id="sdiDocker_installNcSimple">
<title>The simple way: Using SQLite</title>
<orderedlist>
<listitem>
<para>Prepare your system for using docker.</para>
</listitem>
<listitem>
<para>Read the <link
xlink:href="https://github.com/nextcloud/docker">Nextcloud docker
image documentation</link>.</para>
</listitem>
<listitem>
<para>Pull the <code>nextcloud</code> container and start it
according to the documentation mapping port 80 to 8080 of your host
system.</para>
<para>Use <command>ssh ... -L 8080:localhost:8080</command>
forwarding the port in question to your local system and direct your
web browser to <uri
xlink:href="http://localhost:8080">http://localhost:8080</uri>.</para>
</listitem>
<listitem>
<para>Continue the installation by entering admin/admin for username
and password.</para>
</listitem>
</orderedlist>
</section>
<section xml:id="sdiDocker_installNcMaria">
<title>The real McCoy: Using <productname>Mariadb</productname></title>
<para><productname>SQLite</productname> is not appropriate for (larger)
production systems. We thus replace it by a
<productname>mariadb</productname> service.</para>
<orderedlist>
<listitem>
<para>Drop the existing containers among with their volumes.</para>
</listitem>
<listitem>
<para>Follow <uri
xlink:href="https://github.com/nextcloud/docker#user-content-base-version---apache">https://github.com/nextcloud/docker#user-content-base-version---apache</uri>.
Create the proposed <filename>docker-compose.yml</filename> file.
Enter require credentials and start the container using <command
xlink:href="https://docs.docker.com/compose">docker-compose</command>
<parameter>up</parameter>.</para>
</listitem>
<listitem>
<para>This time we choose <productname>Mariadb</productname> as
database server. Connect to <uri
xlink:href="http://localhost:8080">http://localhost:8080</uri>
again. Use the database server's container name as hostname
parameter allowing the <productname>nextcloud</productname>
container to access the <productname>mariadb</productname> service.
Then fill in the remaining required connection parameter
values.</para>
</listitem>
<listitem>
<para>Now configure <uri>ldap://ldap1.hdm-stuttgart.de</uri> as your
credential provider like you did in your regular
<productname>Nextcloud</productname> installation before. The log in
using your regular credentials.</para>
</listitem>
</orderedlist>
</section>
</section>
</chapter>