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== Installation == | == Installation == | ||
The Docker package is in the 'Community' repository. See [[Alpine_Linux_package_management]] how to add a repository. | |||
apk add docker | |||
To start the Docker daemon at boot, see [[Alpine_Linux_Init_System]]. | |||
rc-update add docker boot | |||
service docker start | |||
{{Note|On older version of Alpine Linux with older version of docker you'll also need to disable some kernel security flags in order to build images:}} | {{Note|On older version of Alpine Linux with older version of docker you'll also need to disable some kernel security flags in order to build images:}} | ||
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=== Docker Compose === | === Docker Compose === | ||
' | 'docker-compose' is in 'Community' repository since Alpine Linux >= 3.10. | ||
apk add docker-compose | |||
For older releases, do: | |||
''' | '''To install docker-compose, first install pip:''' | ||
apk add py-pip python3-dev libffi-dev openssl-dev gcc libc-dev make | |||
pip3 install docker-compose</code> | |||
== Isolate containers with a user namespace == | == Isolate containers with a user namespace == | ||
Line 54: | Line 42: | ||
</pre> | </pre> | ||
and add in '''/etc/ | and add in '''/etc/docker/daemon.json''' | ||
<pre> | <pre> | ||
{ | |||
"userns-remap": "dockremap" | |||
} | |||
</pre> | </pre> | ||
''You may also consider these options : '''- | ''You may also consider these options : ''' | ||
"experimental": false, | |||
"live-restore": true, | |||
"ipv6": false, | |||
"icc": false, | |||
"no-new-privileges": false''''' | |||
You will find all possible configurations here[https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-configuration-file]. | |||
== Example: How to install docker from Arch == | == Example: How to install docker from Arch == | ||
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== "WARNING: No {swap,memory} limit support" == | == "WARNING: No {swap,memory} limit support" == | ||
You may, probably encounter this message by executing <code>docker info</code>. | You may, probably, encounter this message by executing <code>docker info</code>. | ||
To correct this situation we have to enable the <code>cgroup_enable=memory swapaccount=1</code> | To correct this situation we have to enable the <code>cgroup_enable=memory swapaccount=1</code> | ||
==== Alpine 3.8 ==== | |||
Well I'm not sure it wasn't the case before but for sure with Alpine 3.8 you must config cgroups properly | |||
'''''Warning''''': This seems ''not'' to work with Alpine 3.9 and Docker 18.06. Follow the instructions for grub or extlinux below instead. | |||
<pre>echo "cgroup /sys/fs/cgroup cgroup defaults 0 0" >> /etc/fstab</pre> | |||
<pre> | |||
cat >> /etc/cgconfig.conf <<EOF | |||
mount { | |||
cpuacct = /cgroup/cpuacct; | |||
memory = /cgroup/memory; | |||
devices = /cgroup/devices; | |||
freezer = /cgroup/freezer; | |||
net_cls = /cgroup/net_cls; | |||
blkio = /cgroup/blkio; | |||
cpuset = /cgroup/cpuset; | |||
cpu = /cgroup/cpu; | |||
} | |||
EOF | |||
</pre> | |||
=== Grub === | === Grub === | ||
Well; if you use Grub it is like any other linux and you just have to add the cgroup condition into <code>/etc/default/grub</code> | Well; if you use Grub it is like any other linux and you just have to add the cgroup condition into <code>/etc/default/grub</code>, then upgrade your grub | ||
<pre>GRUB_CMDLINE_LINUX_DEFAULT="... e=memory swapaccount=1"</pre> | <pre>GRUB_CMDLINE_LINUX_DEFAULT="... e=memory swapaccount=1"</pre> | ||
=== Extlinux === | === Extlinux === | ||
Line 100: | Line 115: | ||
== See also == | == See also == | ||
* [https://www.erianna.com/creating-a-alpine-linux-repository/ Creating & Hosting an Alpine Linux Package Repository for Docker Packages] | * [https://www.erianna.com/creating-a-alpine-linux-repository/ Creating & Hosting an Alpine Linux Package Repository for Docker Packages] | ||
* [[Running Alpine in a Docker Container]] | |||
[[Category:Virtualization]] | [[Category:Virtualization]] |
Revision as of 20:04, 24 April 2020
Installation
The Docker package is in the 'Community' repository. See Alpine_Linux_package_management how to add a repository.
apk add docker
To start the Docker daemon at boot, see Alpine_Linux_Init_System.
rc-update add docker boot service docker start
sysctl -w kernel.grsecurity.chroot_deny_chmod=0
sysctl -w kernel.grsecurity.chroot_deny_mknod=0
For more information, have a look at the corresponding Github issue.
Anyway, this weakening of security is not necessary to do with Alpine 3.4.x and Docker 1.12 as of August 2016 anymore.
Docker Compose
'docker-compose' is in 'Community' repository since Alpine Linux >= 3.10.
apk add docker-compose
For older releases, do:
To install docker-compose, first install pip:
apk add py-pip python3-dev libffi-dev openssl-dev gcc libc-dev make pip3 install docker-compose
Isolate containers with a user namespace
adduser -SDHs /sbin/nologin dockremap addgroup -S dockremap echo dockremap:$(cat /etc/passwd|grep dockremap|cut -d: -f3):65536 >> /etc/subuid echo dockremap:$(cat /etc/passwd|grep dockremap|cut -d: -f4):65536 >> /etc/subgid
and add in /etc/docker/daemon.json
{ "userns-remap": "dockremap" }
You may also consider these options : '
"experimental": false, "live-restore": true, "ipv6": false, "icc": false, "no-new-privileges": false
You will find all possible configurations here[1].
Example: How to install docker from Arch
https://wiki.archlinux.org/index.php/Docker
"WARNING: No {swap,memory} limit support"
You may, probably, encounter this message by executing docker info
.
To correct this situation we have to enable the cgroup_enable=memory swapaccount=1
Alpine 3.8
Well I'm not sure it wasn't the case before but for sure with Alpine 3.8 you must config cgroups properly
Warning: This seems not to work with Alpine 3.9 and Docker 18.06. Follow the instructions for grub or extlinux below instead.
echo "cgroup /sys/fs/cgroup cgroup defaults 0 0" >> /etc/fstab
cat >> /etc/cgconfig.conf <<EOF mount { cpuacct = /cgroup/cpuacct; memory = /cgroup/memory; devices = /cgroup/devices; freezer = /cgroup/freezer; net_cls = /cgroup/net_cls; blkio = /cgroup/blkio; cpuset = /cgroup/cpuset; cpu = /cgroup/cpu; } EOF
Grub
Well; if you use Grub it is like any other linux and you just have to add the cgroup condition into /etc/default/grub
, then upgrade your grub
GRUB_CMDLINE_LINUX_DEFAULT="... e=memory swapaccount=1"
Extlinux
With Extlinux you also add the cgroup condition but inside /etc/update-extlinux.conf
default_kernel_opts="... cgroup_enable=memory swapaccount=1"
than update the config and reboot
update-extlinux
How to use docker
The best documentation for how to use Docker and create containers is at the main docker site. Adding anything more to it here would be redundant.
if you create an account at docker.com you can browse through other user's images and learn from the syntax in contributor's dockerfiles.
Official Docker image files are denoted by a blue ribon on the website.