use a single Dockerfile with build-args

Dockerfile

@@ -1,5 +1,8 @@
 FROM scratch
 
+ARG BOOTSTRAP_VERSION=2021.02.11-r1
+ARG BOOTSTRAP_ARCH=i686
+
 ENV ANDROID_DATA     /data
 ENV ANDROID_ROOT     /system
 ENV HOME             /data/data/com.termux/files/home
@@ -14,7 +17,7 @@ ENV PATH /system/bin
 SHELL ["/system/bin/sh", "-c"]
 
 # Bootstrapping Termux environment.
-ADD https://github.com/termux/termux-packages/releases/download/bootstrap-2021.02.11-r1/bootstrap-i686.zip /data/data/com.termux/files/bootstrap.zip
+ADD https://github.com/termux/termux-packages/releases/download/bootstrap-$BOOTSTRAP_VERSION/bootstrap-$BOOTSTRAP_ARCH.zip /data/data/com.termux/files/bootstrap.zip
 COPY /system /system
 RUN /system/setup-termux.sh
 

Dockerfile.64bit

@@ -1,34 +0,0 @@
-FROM scratch
-
-ENV ANDROID_DATA     /data
-ENV ANDROID_ROOT     /system
-ENV HOME             /data/data/com.termux/files/home
-ENV LANG             en_US.UTF-8
-ENV PREFIX           /data/data/com.termux/files/usr
-ENV TMPDIR           /data/data/com.termux/files/usr/tmp
-ENV TZ               UTC
-
-# Temporary set PATH to /system/bin so we will be able to
-# bootstrap Termux environment.
-ENV PATH /system/bin
-SHELL ["/system/bin/sh", "-c"]
-
-# Bootstrapping Termux environment.
-ADD https://github.com/termux/termux-packages/releases/download/bootstrap-2021.02.11-r1/bootstrap-x86_64.zip /data/data/com.termux/files/bootstrap.zip
-COPY /system /system
-RUN /system/setup-termux.sh
-
-# Switch to Termux environment.
-WORKDIR /data/data/com.termux/files/home
-USER 1000:1000
-ENV PATH /data/data/com.termux/files/usr/bin
-
-# Install package updates.
-# Install package updates.
-RUN /system/bin/update-static-dns && \
-    apt update && \
-    yes | apt upgrade && \
-    rm -rf /data/data/com.termux/files/usr/var/log/apt/* && \
-    rm -rf /data/data/com.termux/cache/apt/*
-
-ENTRYPOINT /data/data/com.termux/files/usr/bin/login

build-all.sh

@@ -4,7 +4,7 @@ set -e
 
 OCI="docker"
 case $1 in
-    -p|--podman) OCI="podman" ;;
+	-p|--podman) OCI="podman" ;;
 esac
 
 if [ -n "${TERMUX_DOCKER_USE_SUDO-}" ]; then
@@ -13,8 +13,15 @@ else
 	SUDO=""
 fi
 
-$SUDO $OCI build -t 'docker.io/xeffyr/termux:latest' -f Dockerfile.32bit .
-$SUDO $OCI build -t 'docker.io/xeffyr/termux:x86_64' -f Dockerfile.64bit .
+for arch in "i686" "x86_64"; do
+	$SUDO $OCI build \
+		-t 'docker.io/xeffyr/termux:'"$arch" \
+		-f Dockerfile \
+		--build-arg BOOTSTRAP_ARCH="$arch" \
+		.
+done
+
+docker tag docker.io/xeffyr/termux:i686 docker.io/xeffyr/termux:latest
 
 if [ "${1-}" = "publish" ]; then
 	$SUDO $OCI push 'docker.io/xeffyr/termux:latest'