99-misc

#!/data/data/com.termux/files/usr/bin/bash

function termux-ubuntu-init() {

  export UBUNTU_CODENAME=${UBUNTU_CODENAME:-focal}
  export INSTALL_DIR=${HOME}/ubuntu-shells/${UBUNTU_CODENAME}
  export CHROOT_DIR=${INSTALL_DIR}/ubuntu-fs
  export NAMESERVERS="1.1.1.1 8.8.8.8"

}

function termux-ubuntu-setup() {

  termux-ubuntu-init

  mkdir -p "${CHROOT_DIR}"
  mkdir -p "${INSTALL_DIR}/binds"

  # check if we have a working ubuntu tarball
  if ! `tar tf ${INSTALL_DIR}/ubuntu.tar.gz &> /dev/null`
  then
    termux-ubuntu-download-tarball ${UBUNTU_CODENAME}
  fi   

  cd ${CHROOT_DIR}
  echo "[+] Deflating ubuntu-image for '${UBUNTU_CODENAME}'..."
  proot --link2symlink tar -xf ${INSTALL_DIR}/ubuntu.tar.gz --exclude='dev'||:

  echo "[+] Setting up nameservers..."
  rm -f ${CHROOT_DIR}/etc/resolv.conf
  for ns in $NAMESERVERS
  do
    echo "nameserver ${ns}" >> ${CHROOT_DIR}/etc/resolv.conf
  done

  cd $OLDPWD

}

function termux-ubuntu-download-tarball() {

    echo "[+] Downloading ubuntu-image"
    case `dpkg --print-architecture` in
    aarch64)
      archurl="arm64" ;;
    arm)
      archurl="armhf" ;;
    amd64)
      archurl="amd64" ;;
    i*86)
      archurl="i386" ;;
    x86_64)
      archurl="amd64" ;;
    *)
      echo "unknown architecture"; exit 1 ;;
    esac
    curl "https://partner-images.canonical.com/core/${UBUNTU_CODENAME}/current/ubuntu-${UBUNTU_CODENAME}-core-cloudimg-${archurl}-root.tar.gz" -o ${INSTALL_DIR}/ubuntu.tar.gz

}

function termux-ubuntu-install-depends() {

  which curl || pkg install curl
  which proot || pkg install proot

}

function termux-ubuntu-exec() {

  UBUNTU_CODENAME=$1
  COMMAND=$(echo $@ | sed "s|${UBUNTU_CODENAME} ||g")
  if [[ -z ${UBUNTU_CODENAME} ]] || [[ -z "${COMMAND}" ]]
  then
    echo "Usage: $FUNCNAME \$UBUNTU_CODENAME \$COMMAND_TO_EXEC"
    echo "Example: $FUNCNAME focal ls"
    return 1
  fi

  termux-ubuntu-init
  
  if [ ! -d "${CHROOT_DIR}" ]
  then
    echo "[!] Setup for '${UBUNTU_CODENAME}' not found, executing 'termux-ubuntu-setup ${UBUNTU_CODENAME}' to install..."
    termux-ubuntu-setup ${UBUNTU_CODENAME}
  fi

  ## unset LD_PRELOAD in case termux-exec is installed
  unset LD_PRELOAD

  proot \
    --link2symlink \
    -0 \
    -r "${CHROOT_DIR}" \
    -b /dev \
    -b /proc \
    -b /data/data/com.termux/files/home:/root \
    -b /sdcard:/mnt/sdcard \
    -w /root \
    /usr/bin/env -i \
    HOME=/root \
    PATH=/usr/local/sbin:/usr/local/bin:/bin:/usr/bin:/sbin:/usr/sbin:/usr/games:/usr/local/games \
    TERM=${TERM} \
    LANG=C.UTF-8 \
    bash -c "${COMMAND}"
}

function termux-ubuntu-shell() {

  UBUNTU_CODENAME=$1
  if [[ -z ${UBUNTU_CODENAME} ]]
  then
    echo "Usage: $FUNCNAME \$UBUNTU_CODENAME"
    echo "Example: $FUNCNAME focal"
    return 1
  fi

  termux-ubuntu-exec ${UBUNTU_CODENAME} bash --login

}