enable integration test on arm64 platform

Currently, integration test can't be done on arm64 platform due to several issues.
 Fix points:
 1, add busybox.tar with arm64 format
 2, add hello-world.tar with arm64 format

Signed-off-by: Bin Lu <bin.lu@arm.com>

Dockerfile

@@ -50,12 +50,13 @@ RUN mkdir -p /usr/src/criu \
 
 # setup a playground for us to spawn containers in
 ENV ROOTFS /busybox
-RUN mkdir -p ${ROOTFS} \
-    && curl -o- -sSL 'https://github.com/docker-library/busybox/raw/a0558a9006ce0dd6f6ec5d56cfd3f32ebeeb815f/glibc/busybox.tar.xz' | tar xfJC - ${ROOTFS}
-
+RUN mkdir -p ${ROOTFS}
 
 COPY script/tmpmount /
 WORKDIR /go/src/github.com/opencontainers/runc
 ENTRYPOINT ["/tmpmount"]
 
 ADD . /go/src/github.com/opencontainers/runc
+
+RUN . tests/integration/multi-arch.bash \
+    && curl -o- -sSL `get_busybox` | tar xfJC - ${ROOTFS}

tests/integration/helpers.bash

@@ -2,6 +2,9 @@
 
 # Root directory of integration tests.
 INTEGRATION_ROOT=$(dirname "$(readlink -f "$BASH_SOURCE")")
+
+. ${INTEGRATION_ROOT}/multi-arch.bash
+
 RUNC="${INTEGRATION_ROOT}/../../runc"
 RECVTTY="${INTEGRATION_ROOT}/../../contrib/cmd/recvtty/recvtty"
 GOPATH="$(mktemp -d --tmpdir runc-integration-gopath.XXXXXX)"
@@ -14,7 +17,8 @@ BUSYBOX_IMAGE="$BATS_TMPDIR/busybox.tar"
 BUSYBOX_BUNDLE="$BATS_TMPDIR/busyboxtest"
 
 # hello-world in tar format
-HELLO_IMAGE="$TESTDATA/hello-world.tar"
+HELLO_FILE=`get_hello`
+HELLO_IMAGE="$TESTDATA/$HELLO_FILE"
 HELLO_BUNDLE="$BATS_TMPDIR/hello-world"
 
 # CRIU PATH
@@ -270,7 +274,7 @@ function setup_busybox() {
 		BUSYBOX_IMAGE="/testdata/busybox.tar"
 	fi
 	if [ ! -e $BUSYBOX_IMAGE ]; then
-		curl -o $BUSYBOX_IMAGE -sSL 'https://github.com/docker-library/busybox/raw/a0558a9006ce0dd6f6ec5d56cfd3f32ebeeb815f/glibc/busybox.tar.xz'
+		curl -o $BUSYBOX_IMAGE -sSL `get_busybox`
 	fi
 	tar --exclude './dev/*' -C "$BUSYBOX_BUNDLE"/rootfs -xf "$BUSYBOX_IMAGE"
 	cd "$BUSYBOX_BUNDLE"

tests/integration/multi-arch.bash

@@ -0,0 +1,22 @@
+#!/bin/bash
+get_busybox(){
+	case $(go env GOARCH) in
+	arm64)
+		echo 'https://github.com/docker-library/busybox/raw/23fbd9c43e0f4bec7605091bfba23db278c367ac/glibc/busybox.tar.xz'
+	;;
+	*)
+		echo 'https://github.com/docker-library/busybox/raw/a0558a9006ce0dd6f6ec5d56cfd3f32ebeeb815f/glibc/busybox.tar.xz'
+	;;
+	esac
+}
+
+get_hello(){
+	case $(go env GOARCH) in
+        arm64)
+                echo 'hello-world-aarch64.tar'
+        ;;
+        *)
+                echo 'hello-world.tar'
+        ;;
+        esac
+}