Install Docker on Termux

answerfile

KEYMAPOPTS="us us"
HOSTNAMEOPTS="-n alpine"
INTERFACESOPTS="auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp
    hostname alpine
"
TIMEZONEOPTS="-z UTC"
PROXYOPTS="none"
APKREPOSOPTS="http://dl-cdn.alpinelinux.org/alpine/v3.12/main http://dl-cdn.alpinelinux.org/alpine/v3.12/community"
SSHDOPTS="-c openssh"
NTPOPTS="-c busybox"
DISKOPTS="-v -m sys -s 0 /dev/sda"

docker-termux.md

Docker on Termux [in a VM]

Create a Linux VM and install Docker in it so you can (slowly) run x86 Docker containers on your Android device.

Recommended to use SSH or external keyboard to execute the following commands unless you want sore thumbs. See https://wiki.termux.com/wiki/Remote_Access#SSH

• Install QEMU

   pkg install qemu-utils qemu-common qemu-system-x86_64-headless
  

• Download Alpine Linux 3.12 (virt optimized) ISO

   mkdir alpine && cd $_
   wget http://dl-cdn.alpinelinux.org/alpine/v3.12/releases/x86_64/alpine-virt-3.12.3-x86_64.iso
  

• Create disk (note it won't actually take 4GB of space, more like 500MB)

   qemu-img create -f qcow2 alpine.img 4G
  

• Boot it up

  qemu-system-x86_64 -machine q35 -m 1024 -smp cpus=2 -cpu qemu64 \
    -drive if=pflash,format=raw,read-only,file=$PREFIX/share/qemu/edk2-x86_64-code.fd \
    -netdev user,id=n1,hostfwd=tcp::2222-:22 -device virtio-net,netdev=n1 \
    -cdrom alpine-virt-3.12.3-x86_64.iso \
    -nographic alpine.img
  

• Login with user root (no password)

• Setup network (press Enter to use defaults):

   localhost:~# setup-interfaces
   Available interfaces are: eth0.
   Enter '?' for help on bridges, bonding and vlans.
   Which one do you want to initialize? (or '?' or 'done') [eth0] 
   Ip address for eth0? (or 'dhcp', 'none', '?') [dhcp] 
   Do you want to do any manual network configuration? [no] 
   localhost:~# ifup eth0
  

• Create an answerfile to speed up installation:

  localhost:~# wget https://gist.githubusercontent.com/oofnikj/e79aef095cd08756f7f26ed244355d62/raw/answerfile
  

• Patch setup-disk to enable serial console output on boot

  localhost:~# sed -i -E 's/(local kernel_opts)=.*/\1="console=ttyS0"/' /sbin/setup-disk
  

• Run setup to install to disk

  localhost:~# setup-alpine -f answerfile
  

• Once installation is complete, power off the VM (command poweroff) and boot again without cdrom:

  qemu-system-x86_64 -machine q35 -m 1024 -smp cpus=2 -cpu qemu64 \
    -drive if=pflash,format=raw,read-only,file=$PREFIX/share/qemu/edk2-x86_64-code.fd \
    -netdev user,id=n1,hostfwd=tcp::2222-:22 -device virtio-net,netdev=n1 \
    -nographic alpine.img
  

• Install docker and enable on boot:

  alpine:~# apk update && apk add docker
  alpine:~# service docker start
  alpine:~# rc-update add docker
  

• Useful keys:

  • Ctrl+a x: quit emulation
  • Ctrl+a h: toggle QEMU console

I am trying to install with the aarch64 qemu but keeps getting
/dev/sda is not a block device suitable for partitioning.

All the step went fine but getting error at the Disk & Install step, looks like it is not able to find the disk.
which I created using:
qemu-img create -f qcow2 alpine.img 20G

I am using below command to boot:
qemu-system-aarch64 -machine virt -m 2048 -smp cpus=2 -cpu max
-drive if=pflash,format=raw,read-only,file=$PREFIX/share/qemu/edk2-aarch64-code.fd
-netdev user,id=n1,hostfwd=tcp::2222-:22 -device virtio-net,netdev=n1
-cdrom alpine-virt-3.19.1-aarch64.iso
-nographic alpine.img

@raj-sharma-git I have a question.

Is there a special reason you want to run arm 64? It is still not accelerated - far slower then x86_64 ( I read about 2x or 4x slower - not sure about this). Do you "need" it?

I consider finding out how that works - I still don't understand the reason.

I thought that the performance would be better because it operates on the same architecture as the phone's processor. My assumption was that it would opt for virtualization instead of emulation, leading to superior performance.