don't set root password in docker image

Dockerfile

@@ -1,7 +1,5 @@
 FROM scratch
 ADD rootfs.tar.gz /
-ARG ROOT_PW
-RUN echo -e "${ROOT_PW}\n${ROOT_PW}" | passwd
 RUN mkdir -p /var/lock
 RUN opkg remove dnsmasq && \
     opkg update && \

Dockerfile.rpi

@@ -1,7 +1,5 @@
 FROM scratch
 COPY . .
-ARG ROOT_PW
-RUN echo -e "${ROOT_PW}\n${ROOT_PW}" | passwd
 RUN mkdir -p /var/lock
 RUN opkg update && \
     opkg install \

Makefile

@@ -14,8 +14,6 @@ rootfs.tar.gz:
 
 build: rootfs.tar.gz
 	docker build \
-		--build-arg ROOT_PW \
-		--build-arg OPENWRT_SOURCE_VER \
 		--build-arg ts="$(shell date)" \
 		--build-arg version="${OPENWRT_SOURCE_VER}" \
 		-t ${IMAGE_TAG} .

build-rpi.sh

@@ -31,7 +31,6 @@ mount_rootfs() {
 docker_build() {
 	echo "* building Docker image"
 	docker build \
-		--build-arg ROOT_PW="${ROOT_PW}" \
 		--build-arg ts="$(date)" \
 		--build-arg version="${VERSION:-$OPENWRT_SOURCE_VER}" \
 		-t ${IMAGE_TAG} -f Dockerfile.rpi ${tmpdir}

openwrt.conf.example

@@ -7,7 +7,6 @@ OPENWRT_SOURCE_VER=19.07.4
 IMAGE_TAG=oofnik/openwrt
 # container name 
 CONTAINER=openwrt_1
-ROOT_PW=changeme123
 
 ## Docker network settings
 # name of the WAN Docker network