ubuntu/debian: create aarch64-specific Dockerfile.in

The musl package in ubuntu/debian could not provide everything we need
on aarch64.
e.g. we need `aarch64-linux-musl-gcc` as linker, and it's not provided
in package.

Fixes: #411

Signed-off-by: Penny Zheng <penny.zheng@arm.com>

rootfs-builder/debian/Dockerfile-aarch64.in

@@ -0,0 +1,35 @@
+#
+# Copyright (c) 2020 ARM Limited
+#
+# SPDX-License-Identifier: Apache-2.0
+
+# NOTE: OS_VERSION is set according to config.sh
+from docker.io/debian:@OS_VERSION@
+
+# RUN commands
+RUN apt-get update && apt-get install -y \
+    autoconf \
+    automake \
+    binutils \
+    build-essential \
+    chrony \
+    cmake \
+    coreutils \
+    curl \
+    debianutils \
+    debootstrap \
+    g++ \
+    gcc \
+    git \
+    libc-dev \
+    libstdc++-6-dev \
+    m4 \
+    make \
+    sed \
+    systemd \
+    tar \
+    vim
+# This will install the proper golang to build Kata components
+@INSTALL_GO@
+@INSTALL_MUSL@
+@INSTALL_RUST@

rootfs-builder/ubuntu/Dockerfile-aarch64.in

@@ -0,0 +1,39 @@
+#
+# Copyright (c) 2020 ARM Limited
+#
+# SPDX-License-Identifier: Apache-2.0
+
+#ubuntu: docker image to be used to create a rootfs
+#@OS_VERSION@: Docker image version to build this dockerfile
+from docker.io/ubuntu:@OS_VERSION@
+
+# This dockerfile needs to provide all the componets need to build a rootfs
+# Install any package need to create a rootfs (package manager, extra tools)
+
+# RUN commands
+RUN apt-get update && apt-get install -y \
+    autoconf \
+    automake \
+    binutils \
+    build-essential \
+    chrony \
+    cmake \
+    coreutils \
+    curl \
+    debianutils \
+    debootstrap \
+    g++ \
+    gcc \
+    git \
+    libc6-dev \
+    libstdc++-8-dev \
+    m4 \
+    make \
+    sed \
+    systemd \
+    tar \
+    vim
+# This will install the proper golang to build Kata components
+@INSTALL_GO@
+@INSTALL_MUSL@
+@INSTALL_RUST@

scripts/lib.sh

@@ -274,7 +274,6 @@ generate_dockerfile()
 	curlOptions=("-OL")
 	[ -n "${http_proxy:-}" ] && curlOptions+=("-x ${http_proxy:-}")
 
-	readonly dockerfile_template="Dockerfile.in"
 	readonly install_go="
 RUN cd /tmp ; curl ${curlOptions[@]} https://storage.googleapis.com/golang/go${GO_VERSION}.linux-${goarch}.tar.gz
 RUN tar -C /usr/ -xzf /tmp/go${GO_VERSION}.linux-${goarch}.tar.gz
@@ -344,7 +343,15 @@ RUN ln -sf /usr/bin/g++ /bin/musl-g++
 	# rust agent still need go to build
 	# because grpc-sys need go to build
 	pushd ${dir}
+	dockerfile_template="Dockerfile.in"
+	dockerfile_arch_template="Dockerfile-${architecture}.in"
+	# if arch-specific docker file exists, swap the univesal one with it.
+        if [ -f "${dockerfile_arch_template}" ]; then
+                dockerfile_template="${dockerfile_arch_template}"
+        else
                 [ -f "${dockerfile_template}" ] || die "${dockerfile_template}: file not found"
+        fi
+
 	# powerpc have no musl target, don't setup rust enviroment
 	# since we cannot static link agent. Besides, there is
 	# also long double representation problem when building musl-libc