Install docker on arm64 synology

get-docker.sh

#!/bin/bash
set -e

ARCH=aarch64
DOCKER_VERSION=20.10.9
COMPOSE_VERSION=2.5.1
DOCKER_DIR=/volume1/@docker

echo "Downloading docker $DOCKER_VERSION-$ARCH"
curl "https://download.docker.com/linux/static/stable/$ARCH/docker-$DOCKER_VERSION.tgz" | tar -xz -C /usr/local/bin --strip-components=1

echo "Creating docker working directory $DOCKER_DIR"
mkdir -p "$DOCKER_DIR"

echo "Creating docker.json config file"
mkdir -p /usr/local/etc/docker
cat <<EOT > /usr/local/etc/docker/docker.json
{
  "storage-driver": "vfs",
  "iptables": false,
  "bridge": "none",
  "data-root": "$DOCKER_DIR"
}
EOT

echo "Creating docker startup script"
cat <<'EOT' > /usr/local/etc/rc.d/docker.sh
#!/bin/sh
# Start docker daemon

NAME=dockerd
PIDFILE=/var/run/$NAME.pid
DAEMON_ARGS="--config-file=/usr/local/etc/docker/docker.json --pidfile=$PIDFILE"

case "$1" in
    start)
        echo "Starting docker daemon"
        # ulimit -n 4096  # needed for influxdb (uncomment if your limit is lower)
        /usr/local/bin/dockerd $DAEMON_ARGS &
        ;;
    stop)
        echo "Stopping docker daemon"
        kill $(cat $PIDFILE)
        ;;
    *)
        echo "Usage: "$1" {start|stop}"
        exit 1
esac
exit 0
EOT

chmod 755 /usr/local/etc/rc.d/docker.sh

echo "Creating docker group"
egrep -q docker /etc/group || synogroup --add docker root

echo "Installing docker compose $COMPOSE_VERSION"
curl -SL "https://github.com/docker/compose/releases/download/v$COMPOSE_VERSION/docker-compose-linux-$ARCH" \
     --create-dirs -o /usr/local/lib/docker/cli-plugins/docker-compose
chmod +x /usr/local/lib/docker/cli-plugins/docker-compose
chgrp -R docker /usr/local/lib/docker

echo "Starting docker"
/usr/local/etc/rc.d/docker.sh start

echo "Done.  Please add your user to the docker group in the Synology GUI and reboot your NAS."

Yeah, I know, I was referring to:

I'm not sure if this will work, but you should try armel or armhf

Just as your information it seems that it is not working just downloading the armhf version, it seems that an extra patch it is needed.

@killkrt Did this resolve? I have an DS214+ and thus an armv7l processor. How did you get it to work with armv7l or where did you find help. Thanks in advance!

@thunermay sorry I cannot recall it, actually I was supporting a friend, so it was not for my NAS. BTW it was quite tricky and it was not fully working, some features were missing (if I am not wrong macvlan and others).

My DS418's umask seems to default to 0077, so I needed to make the following change to use docker compose:

@@ -57,7 +57,7 @@
 echo "Installing docker compose $COMPOSE_VERSION"
 curl -SL "https://github.com/docker/compose/releases/download/v$COMPOSE_VERSION/docker-compose-linux-$ARCH" \
      --create-dirs -o /usr/local/lib/docker/cli-plugins/docker-compose
-chmod +x /usr/local/lib/docker/cli-plugins/docker-compose
+chmod -R ug+rx /usr/local/lib/docker
 chgrp -R docker /usr/local/lib/docker

I have a DS418 and this script worked, in that the components were installed as expected and docker could be started and stopped.

However, these lines:
https://gist.github.com/DaveMDS/c35d77e51e0186a4fe2e577f51a5b09a#file-get-docker-sh-L20-L21
mean that containers are isolated from the outside world.

If you remove "bridge" and "iptables" from docker.json, then you get error message about "can't initialize iptables table 'nat'" at docker startup. I resolved these by running "modprobe nf_nat_ipv4 iptable_nat" before starting docker. After that, containers are able to make external connections via the bridge network.

Perhaps you could add that to your startup script.