test: backport TEST-81-GENERATORS (fstab-generator only)

Some fstab-generator features are not present on RHEL 7 or they behave
differently - in such case there's an inline comment explaining what's
different with a reference to an upstream commit that introduced the
changed behavior.

Also, RHEL 7 systemd doesn't allow overriding (/sysroot)/etc/fstab or
/proc/cmdline, so instead of backporting another bunch of potential
risky commits, let's temporarily bind-mount a modified copy of necessary
files in place of the expected ones. One exception is
$SYSTEMD_IN_INITRD, since systemd checks if the mount for / is a tmpfs,
which is a pain to mock, but the patch for that is, thankfully, pretty
small.

Related: RHEL-17394

rhel-only

test/TEST-81-GENERATORS/Makefile

@@ -0,0 +1 @@
+../TEST-01-BASIC/Makefile

test/TEST-81-GENERATORS/generator-utils.sh

@@ -0,0 +1,110 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+link_endswith() {
+    [[ -h "${1:?}" && "$(readlink "${1:?}")" =~ ${2:?}$ ]]
+}
+
+link_eq() {
+    [[ -h "${1:?}" && "$(readlink "${1:?}")" == "${2:?}" ]]
+}
+
+# Get the value from a 'key=value' assignment
+opt_get_arg() {
+    local arg
+
+    IFS="=" read -r _ arg <<< "${1:?}"
+    test -n "$arg"
+    echo "$arg"
+}
+
+in_initrd() {
+    [[ "${SYSTEMD_IN_INITRD:-0}" -ne 0 ]]
+}
+
+# Check if we're parsing host's fstab in initrd
+in_initrd_host() {
+    in_initrd && [[ "${SYSTEMD_SYSROOT_FSTAB:-/dev/null}" != /dev/null ]]
+}
+
+in_container() {
+    systemd-detect-virt -qc
+}
+
+opt_filter() (
+    set +x
+    local opt split_options filtered_options
+
+    IFS="," read -ra split_options <<< "${1:?}"
+    for opt in "${split_options[@]}"; do
+        if [[ "$opt" =~ ${2:?} ]]; then
+            continue
+        fi
+
+        filtered_options+=("$opt")
+    done
+
+    IFS=","; printf "%s" "${filtered_options[*]}"
+)
+
+# Run the given generator $1 with target directory $2 - clean the target
+# directory beforehand
+run_and_list() {
+    local generator="${1:?}"
+    local out_dir="${2:?}"
+    local environ
+    local cmdline
+
+    # If $PID1_ENVIRON is set temporarily overmount /proc/1/environ with
+    # a temporary file that contains contents of $PID1_ENVIRON. This is
+    # necessary in cases where the generator reads the environment through
+    # getenv_for_pid(1, ...) or similar like getty-generator does.
+    #
+    # Note: $PID1_ENVIRON should be a NUL separated list of env assignments
+    if [[ -n "${PID1_ENVIRON:-}" ]]; then
+        environ="$(mktemp)"
+        echo -ne "${PID1_ENVIRON}\0" >"${environ:?}"
+        mount -v --bind "$environ" /proc/1/environ
+    fi
+
+    if [[ -n "${SYSTEMD_PROC_CMDLINE:-}" ]]; then
+        cmdline="$(mktemp)"
+        echo "$SYSTEMD_PROC_CMDLINE" >"$cmdline"
+        mount --bind "$cmdline" /proc/cmdline
+    fi
+
+    if [[ -n "${SYSTEMD_FSTAB:-}" ]]; then
+        touch /etc/fstab
+        mount --bind "$SYSTEMD_FSTAB" /etc/fstab
+    fi
+
+    if [[ -n "${SYSTEMD_SYSROOT_FSTAB:-}" ]]; then
+        mkdir -p /sysroot/etc
+        touch /sysroot/etc/fstab
+        mount --bind "$SYSTEMD_SYSROOT_FSTAB" /sysroot/etc/fstab
+    fi
+
+    rm -fr "${out_dir:?}"/*
+    mkdir -p "$out_dir"/{normal,early,late}
+    SYSTEMD_LOG_LEVEL="${SYSTEMD_LOG_LEVEL:-debug}" "$generator" "$out_dir/normal" "$out_dir/early" "$out_dir/late"
+    ls -lR "$out_dir"
+
+    if [[ -n "${SYSTEMD_SYSROOT_FSTAB:-}" ]]; then
+        umount /sysroot/etc/fstab
+        rm -rf /sysroot
+    fi
+
+    if [[ -n "${SYSTEMD_FSTAB:-}" ]]; then
+        umount /etc/fstab
+    fi
+
+    if [[ -n "${SYSTEMD_PROC_CMDLINE:-}" ]]; then
+        umount /proc/cmdline
+        rm -f "$cmdline"
+    fi
+
+    if [[ -n "${environ:-}" ]]; then
+        umount /proc/1/environ
+        rm -f "$environ"
+    fi
+}

test/TEST-81-GENERATORS/test.sh

@@ -0,0 +1,85 @@
+#!/usr/bin/bash
+set -e
+TEST_DESCRIPTION="Test systemd generators"
+
+# shellcheck source=test/test-functions
+. "$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
+    [[ -f $TESTDIR/root/var/log/journal ]] && 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 $ret
+}
+
+test_run() {
+    if run_qemu; then
+        check_result_qemu || return 1
+    else
+        dwarn "can't run QEMU, skipping"
+    fi
+    if check_nspawn; then
+        run_nspawn
+        check_result_nspawn || return 1
+    else
+        dwarn "can't run systemd-nspawn, skipping"
+    fi
+    return 0
+}
+
+test_setup() {
+    create_empty_image
+    mkdir -p "${TESTDIR:?}/root"
+    mount "${LOOPDEV:?}p1" "$TESTDIR/root"
+
+    (
+        LOG_LEVEL=5
+        # shellcheck disable=SC2046
+        eval $(udevadm info --export --query=env --name="${LOOPDEV}p2")
+
+        setup_basic_environment
+
+        # mask some services that we do not want to run in these tests
+        ln -fs /dev/null "$initdir/etc/systemd/system/systemd-hwdb-update.service"
+        ln -fs /dev/null "$initdir/etc/systemd/system/systemd-journal-catalog-update.service"
+        ln -fs /dev/null "$initdir/etc/systemd/system/systemd-networkd.service"
+        ln -fs /dev/null "$initdir/etc/systemd/system/systemd-networkd.socket"
+        ln -fs /dev/null "$initdir/etc/systemd/system/systemd-resolved.service"
+        ln -fs /dev/null "$initdir/etc/systemd/system/systemd-machined.service"
+
+        # setup the testsuite service
+        cat >"$initdir/etc/systemd/system/testsuite.service" <<EOF
+[Unit]
+Description=Testsuite service
+
+[Service]
+ExecStart=/bin/bash -x /testsuite.sh
+Type=oneshot
+StandardOutput=tty
+StandardError=tty
+NotifyAccess=all
+EOF
+        cp generator-utils.sh testsuite*.sh "$initdir/"
+
+        setup_testsuite
+    ) || return 1
+    setup_nspawn_root
+
+    ddebug "umount $TESTDIR/root"
+    umount "$TESTDIR/root"
+}
+
+test_cleanup() {
+    umount $TESTDIR/root 2>/dev/null
+    [[ $LOOPDEV ]] && losetup -d $LOOPDEV
+    return 0
+}
+
+do_test "$@"