Setup docker on the steamdeck

docker.service

[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target docker.socket firewalld.service containerd.service time-set.target
Wants=network-online.target containerd.service
Requires=docker.socket

[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd -H fd:// 
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutStartSec=0
RestartSec=2
Restart=always

# Note that StartLimit* options were moved from "Service" to "Unit" in systemd 229.
# Both the old, and new location are accepted by systemd 229 and up, so using the old location
# to make them work for either version of systemd.
StartLimitBurst=3

# Note that StartLimitInterval was renamed to StartLimitIntervalSec in systemd 230.
# Both the old, and new name are accepted by systemd 230 and up, so using the old name to make
# this option work for either version of systemd.
StartLimitInterval=60s

# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity

# Comment TasksMax if your systemd version does not support it.
# Only systemd 226 and above support this option.
TasksMax=infinity

# set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes

# kill only the docker process, not all processes in the cgroup
KillMode=process
OOMScoreAdjust=-500

[Install]
WantedBy=multi-user.target

steam_deck_setup.sh

sudo pacman-key --init
pacman-key --populate archlinux
sudo pacman -S gnome-terminal

wget https://download.docker.com/linux/static/stable/x86_64/docker-20.10.9.tgz
tar xzvf ./docker-20.10.9.tgz
sudo cp docker/* /usr/bin/

sudo wget https://gist.githubusercontent.com/aarondewindt/99a7ea09d00813bccab5953f40010ace/raw/6ea68b56457804096fdc64b147410ac4f832d336/docker.service -P /etc/systemd/system
sudo wget https://raw.githubusercontent.com/moby/moby/master/contrib/init/systemd/docker.socket -P /etc/systemd/system

sudo systemctl enable docker
sudo systemctl start docker

Hi, mate! You need to create group docker before starting services.

sudo groupadd docker