Termux environment for Docker/Podman.

A Termux environment packaged into Docker image. Environment doesn't have Android runtime components, so certain things will not be available (DalvikVM, OpenSLES, etc...).

How to use

Requirements

You should have a properly configured and running Docker or Podman container systems. Further instructions will provide examples only for Docker.

Basic usage

This will start interactive login shell. Everything will look like in a normal Termux installation.

docker run -it termux/termux-docker:latest

When using the tag latest, container will be 32 bit (i686 architecture).

Other architecture can be installed using a different tags. Available tags:

• aarch64
• arm
• i686 (latest)
• x86_64

If architecture is not compatible with host, the additional setup will be needed. Read this document further to learn how you can run containers of incompatible CPU architecture.

Important note: do not pass --user option to Docker command line. The initial user of container must be root. Otherwise DNS will be broken because of dnsmasq server failure.

Running ARM containers on x86 host

In order to run AArch64 container on x86(64) host, you need to setup QEMU emulator through binfmt_misc. This can be easily done by one command:

docker run --rm --privileged aptman/qus -s -- -p aarch64 arm

Note that AArch64 and ARM containers work properly only in privileged mode. If you want your containers to have standard privileges, a custom seccomp profile is required.

Variant with privileged container:

docker run -it --privileged termux/termux-docker:aarch64

Variant with seccomp unconfined profile:

docker run -it --security-opt seccomp:unconfined termux/termux-docker:aarch64

Non-interactive execution of commands

You can run commands in non-interactive mode. Just append them to Docker command line.

Example:

docker run -it --rm termux/termux-docker:latest bash -c "apt update && apt install -yq clang"

Root shell

By default root shell is disabled in container as Termux doesn't really support usage of package manager under root account. In cases where you really need shell with root privileges, entrypoint should be overridden.

The provided images have 2 entry points:

• /entrypoint.sh - the standard one which drops privileges to system user.
• /entrypoint_root.sh - alternate entrypoint that does not drop privileges.

Usage example:

docker run -it --entrypoint /entrypoint_root.sh termux/termux-docker:latest

Building image

Docker:

./build-all.sh

Podman:

./build-all.sh --podman

Known issues

There a number of known issues which may not be resolved:

• ARM containers may require a custom seccomp profile to remove restrictions from personality() system call.

• When running certain multi threaded program in 32bit containers, the PIDs can balloon and easily exceed libc's limit. The only way to fix this is to set /proc/sys/kernel/pid_max to 65536. See termux-docker#40.