Termux + Qemu + Alpine + Docker + VNC

This is a setup for runing docker on android, by the means of Termux, running alpine in qemu and them enabling docker on the Alpine.

This was only tested on Samsung S10e.

Install Termux

And start it.

Setup VNC + Fluxbox

First step was to setup VNC and Fluxbox, which is quite easy following termux VNC guide:

Enable x11 repository, install tiger-vnc and fluxbox:

pkg install x11-repo
pkg install tigervnc fluxbox

Them start vncserver, it will ask you to setup password and other options, just follow on screen instructions:

vncserver

Xvnc will them be running in background. We can now start fluxbox:

DISPLAY=":1" fluxbox

This will start fluxbox on the Xvnc server and lock the current terminal. You can also append an "&" on that command to start it in background.

You can stop fluxbox on the remote desktop.

You can stop vnc:

vncserver -kill :1

To access your VNC server, choose your RDP client (like Vinagre on Ubuntu, or VNC Viewer on Android) and connect to your phone IP on port 5901 (for display :1).

To discover your phone IP on the wifi:

ip addr show wlan0

Inside Fluxbox you can right-click on the desktop to get a menu and launch stuff like "aterm".

Setup QEMU

Qemu setup is quite easy, just small gotcha is that I had to use qemu from x11-repo instead of unstable headless, and do not really know why.

Installing Qemu:

pkg install unstable-repo
pkg install qemu-system-x64_64 qemu-utils

That is it.

Preparing to install Alpine on Qemu

You will need the Alpine virtual ISO, that you can download from alpine website. Save it as alpine.iso to easy the typing:

pkg install curl
curl http://dl-cdn.alpinelinux.org/alpine/v3.10/releases/x86_64/alpine-virt-3.10.1-x86_64.iso -o alpine.iso

Them you will need an image disk for the alpine installation to reside in:

qemu-img create -f qcow2 alpine.img 5g

Starting Alpine installation on QEMU

Them you can launch Qemu installation of Alpine. I fyou are on an XVNC session, it will launch a QEMU window.

qemu-system-x86_64 -hda alpine.img -cdrom alpine.iso -boot d -m 512

If you want to keep on the same terminal (not launching a new window) you can append "-nographic" to that last command.

If you are on a QEMU window you can click it to grab focus, and can CTRL+ALT+G to release focus. You can also CTRL+ALT+F to go fullscreen.

On a terminal, you can stop emulation with CTRL+A+X. There are several others Ctrl+A commands.

It will take a while for alpine to boot, but will them present you with a "Login:" terminal, just enter "root" to start.

Setting up networking on Alpine on Qemu

This is a part that I had trouble, before starting setup inside alpine, you should setup proper network.

First, setup the interfaces, by editing /etc/network/interfaces to have the following content:

auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp

Save it, and restart the alpine network:

/etc/init.d/networking restart

You should get an IP from the Qemu user network. Please be aware that ping does not work on this setup.

Them, and only them, you also need to add DNS servers, by editing /etc/resolv.conf to the following:

nameserver 8.8.8.8

You can test by trying to setup just the repositories:

setup-apkrepos

If this gives you a list of repos to choose from (About 40+), them it worked.

Installing Alpine

To start installation:

setup-alpine

Just follow on screen instructions with attention. Be sure to choose to install on disk "sda" when prompted.

Once the installation is complete, shutdown Alpine by issuing halt"

halt

When it says system halted, exit Qemu (either by CTRL+Alt+g and closing window, or by ctrl+a+x on the terminal).

Running installed Alpine on Qemu

To start alpine, simply run:

qemu-system-x86_64 -hda alpine.img -boot c -m 512

It will be take a while and give you a login prompt for the root user you setup.

Installing Docker on Alpine

The reason I installed it all is to run docker on alpine.

On alpine, edit /etc/pkg/repositories and uncomment comunity repository, them install docker:

apk update
apk add docker

Start the service and enable it on boot:

service start docker
update-rc enable docker

Test it out

docker info
docker run alpine echo hello

How slow is it?

On my machine a simple hello world take 1s to echo, while on this setup it takes 25s. Well, at least it works...