fix(libcontainer): bats test for rootfs propagation

add bat integration test for rootfs propagation test, expect to
see the mount propagation is slave, the test will create a isolate mntns
to run the test as the test will mutate the rootfs propagation

Signed-off-by: sean <xujihui1985@gmail.com>

Author: xujihui1985

tests/integration/mounts_propagation_unsafe.bats

@@ -0,0 +1,74 @@
+#!/usr/bin/env bats
+
+load helpers
+
+function require_mount_namespace_tools() {
+	command -v unshare >/dev/null || skip "test requires unshare"
+	command -v nsenter >/dev/null || skip "test requires nsenter"
+}
+
+function in_mount_namespace() {
+	local cwd
+	cwd="$(pwd)"
+	nsenter --mount="$ISOLATED_MNTNS" -- sh -c "cd \"\$1\" && shift && exec \"\$@\"" sh "$cwd" "$@"
+}
+
+function setup_isolated_mount_namespace() {
+	ISOLATED_MNTNS_DIR="$(mktemp -d "$BATS_RUN_TMPDIR/mntns.XXXXXX")"
+	mount --bind "$ISOLATED_MNTNS_DIR" "$ISOLATED_MNTNS_DIR"
+	mount --make-private "$ISOLATED_MNTNS_DIR"
+
+	ISOLATED_MNTNS="$ISOLATED_MNTNS_DIR/testns"
+	touch "$ISOLATED_MNTNS"
+	if ! unshare --mount="$ISOLATED_MNTNS" mount --make-rprivate /; then
+		rm -f "$ISOLATED_MNTNS"
+		umount "$ISOLATED_MNTNS_DIR" 2>/dev/null || true
+		rmdir "$ISOLATED_MNTNS_DIR" 2>/dev/null || true
+		fail "failed to bind isolated mount namespace"
+	fi
+}
+
+function teardown_isolated_mount_namespace() {
+	if [ -n "${ISOLATED_MNTNS_DIR:-}" ]; then
+		umount -l "$ISOLATED_MNTNS_DIR" 2>/dev/null || true
+		rmdir "$ISOLATED_MNTNS_DIR" 2>/dev/null || true
+	fi
+}
+
+function __runc_in_mount_namespace() {
+	setup_runc_cmdline
+	in_mount_namespace "${RUNC_CMDLINE[@]}" "$@"
+}
+
+function make_rootfs_shared() {
+	in_mount_namespace mount --make-rshared /
+}
+
+function runc_in_mount_namespace() {
+	CMDNAME="$(basename "$RUNC")" sane_run __runc_in_mount_namespace "$@"
+}
+
+function setup() {
+	requires root
+	require_mount_namespace_tools
+
+	setup_isolated_mount_namespace
+	make_rootfs_shared
+	setup_debian
+}
+
+function teardown() {
+	teardown_bundle
+	teardown_isolated_mount_namespace
+}
+
+@test "runc run [rootfsPropagation slave]" {
+	# make sure the rootfs mount is slave before running the test
+	update_config ' .linux.rootfsPropagation = "slave" '
+
+	update_config ' .process.args = ["findmnt", "--noheadings", "-o", "PROPAGATION", "/"] '
+
+	runc_in_mount_namespace run test_slave_rootfs
+	[ "$status" -eq 0 ]
+	[ "$output" = "private,slave" ]
+}