tests: add smoke test for systemd-nspawn

Basically, this test runs:
```
    systemd-nspawn --register=no -D "$_root" -b
    systemd-nspawn --register=no -D "$_root" --private-network -b
    systemd-nspawn --register=no -D "$_root" -U -b
    systemd-nspawn --register=no -D "$_root" --private-network -U -b
```
and exports the `UNIFIED_CGROUP_HIERARCHY=[yes|no]`, `SYSTEMD_NSPAWN_USE_CGNS=[yes|no]`

Inspired by
* systemd#3589 (comment)
* systemd#4372 (comment)
* systemd#4223 (comment)
* systemd#1555

and so on :-)

1 files changed, 138 insertions, 0 deletions

diff --git a/test/TEST-13-NSPAWN-SMOKE/test.sh b/test/TEST-13-NSPAWN-SMOKE/test.sh
new file mode 100755
index 0000000000..dfc437c0ee
--- /dev/null
+++ b/test/TEST-13-NSPAWN-SMOKE/test.sh
@@ -0,0 +1,138 @@
+#!/bin/bash
+# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
+# ex: ts=8 sw=4 sts=4 et filetype=sh
+TEST_DESCRIPTION="systemd-nspawn smoke test"
+SKIP_INITRD=yes
+. $TEST_BASE_DIR/test-functions
+
+check_result_qemu() {
+    ret=1
+    mkdir -p $TESTDIR/root
+    mount ${LOOPDEV}p1 $TESTDIR/root
+    [[ -e $TESTDIR/root/testok ]] && ret=0
+    [[ -f $TESTDIR/root/failed ]] && cp -a $TESTDIR/root/failed $TESTDIR
+    cp -a $TESTDIR/root/var/log/journal $TESTDIR
+    umount $TESTDIR/root
+    [[ -f $TESTDIR/failed ]] && cat $TESTDIR/failed
+    ls -l $TESTDIR/journal/*/*.journal
+    test -s $TESTDIR/failed && ret=$(($ret+1))
+    return $ret
+}
+
+test_run() {
+    if run_qemu; then
+        check_result_qemu || return 1
+    else
+        dwarn "can't run QEMU, skipping"
+    fi
+    return 0
+}
+
+test_setup() {
+    create_empty_image
+    mkdir -p $TESTDIR/root
+    mount ${LOOPDEV}p1 $TESTDIR/root
+
+    # Create what will eventually be our root filesystem onto an overlay
+    (
+        LOG_LEVEL=5
+        eval $(udevadm info --export --query=env --name=${LOOPDEV}p2)
+
+        setup_basic_environment
+        dracut_install busybox chmod rmdir
+        dracut_install ./has-overflow
+
+        cp create-busybox-container $initdir/
+
+        # setup the testsuite service
+        cat >$initdir/etc/systemd/system/testsuite.service <<EOF
+[Unit]
+Description=Testsuite service
+After=multi-user.target
+
+[Service]
+ExecStart=/test-nspawn.sh
+Type=oneshot
+EOF
+
+        cat >$initdir/test-nspawn.sh <<'EOF'
+#!/bin/bash
+set -x
+set -e
+set -u
+set -o pipefail
+
+export SYSTEMD_LOG_LEVEL=debug
+
+# check cgroup-v2
+is_v2_supported=no
+mkdir -p /tmp/cgroup2
+if mount -t cgroup2 cgroup2 /tmp/cgroup2; then
+    is_v2_supported=yes
+    umount /tmp/cgroup2
+fi
+rmdir /tmp/cgroup2
+
+# check cgroup namespaces
+is_cgns_supported=no
+if [[ -f /proc/1/ns/cgroup ]]; then
+    is_cgns_supported=yes
+fi
+
+function run {
+    if [[ "$1" = "yes" && "$is_v2_supported" = "no" ]]; then
+        printf "Unified cgroup hierarchy is not supported. Skipping.\n" >&2
+        return 0
+    fi
+    if [[ "$2" = "yes" && "$is_cgns_supported" = "no" ]];  then
+        printf "Cgroup namespaces are not supported. Skipping.\n" >&2
+        return 0
+    fi
+
+    local _root="/var/lib/machines/unified-$1-cgns-$2"
+    /create-busybox-container "$_root"
+    UNIFIED_CGROUP_HIERARCHY="$1" SYSTEMD_NSPAWN_USE_CGNS="$2" systemd-nspawn --register=no -D "$_root" -b
+    UNIFIED_CGROUP_HIERARCHY="$1" SYSTEMD_NSPAWN_USE_CGNS="$2" systemd-nspawn --register=no -D "$_root" --private-network -b
+
+    if ! UNIFIED_CGROUP_HIERARCHY="$1" SYSTEMD_NSPAWN_USE_CGNS="$2" systemd-nspawn --register=no -D "$_root" -U -b; then
+        if [[ "$1" = "no" && "$2" = "yes" ]] && /has-overflow -M '0 1073283072 65536' -G '0 1073283072 65536'; then
+            printf "Failure expected, ignoring (see https://github.com/systemd/systemd/issues/4352)\n" >&2
+        else
+            return 1
+        fi
+    fi
+
+    if ! UNIFIED_CGROUP_HIERARCHY="$1" SYSTEMD_NSPAWN_USE_CGNS="$2" systemd-nspawn --register=no -D "$_root" --private-network -U -b; then
+        if [[ "$1" = "no" && "$2" = "yes" ]] && /has-overflow -M '0 1073283072 65536' -G '0 1073283072 65536'; then
+            printf "Failure expected, ignoring (see https://github.com/systemd/systemd/issues/4352)\n" >&2
+        else
+            return 1
+        fi
+    fi
+
+    return 0
+}
+
+run no no
+run yes no
+run no yes
+run yes yes
+
+touch /testok
+EOF
+
+        chmod 0755 $initdir/test-nspawn.sh
+        setup_testsuite
+    ) || return 1
+
+    ddebug "umount $TESTDIR/root"
+    umount $TESTDIR/root
+}
+
+test_cleanup() {
+    umount $TESTDIR/root 2>/dev/null
+    [[ $LOOPDEV ]] && losetup -d $LOOPDEV
+    return 0
+}
+
+do_test "$@"