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#! @perl@/bin/perl
# Issue #166838 uncovered a situation in which a configuration not suitable
# for the target architecture caused a cryptic error message instead of
# a clean failure. Due to this mismatch, the perl interpreter in the shebang
# line wasn't able to be executed, causing this script to be misinterpreted
# as a shell script.
#
# Let's detect this situation to give a more meaningful error
# message. The following two lines are carefully written to be both valid Perl
# and Bash.
printf "Perl script erroneously interpreted as shell script,\ndoes target platform match nixpkgs.crossSystem platform?\n" && exit 1
if 0;
use strict;
use warnings;
use Config::IniFiles;
use File::Path qw(make_path);
use File::Basename;
use File::Slurp qw(read_file write_file edit_file);
use JSON::PP;
use IPC::Cmd;
use Sys::Syslog qw(:standard :macros);
use Cwd qw(abs_path);
## no critic(ControlStructures::ProhibitDeepNests)
## no critic(ErrorHandling::RequireCarping)
## no critic(CodeLayout::ProhibitParensWithBuiltins)
## no critic(Variables::ProhibitPunctuationVars, Variables::RequireLocalizedPunctuationVars)
## no critic(InputOutput::RequireCheckedSyscalls, InputOutput::RequireBracedFileHandleWithPrint, InputOutput::RequireBriefOpen)
## no critic(ValuesAndExpressions::ProhibitNoisyQuotes, ValuesAndExpressions::ProhibitMagicNumbers, ValuesAndExpressions::ProhibitEmptyQuotes, ValuesAndExpressions::ProhibitInterpolationOfLiterals)
## no critic(RegularExpressions::ProhibitEscapedMetacharacters)
# System closure path to switch to
my $out = "@out@";
# Path to the directory containing systemd tools of the old system
my $cur_systemd = abs_path("/run/current-system/sw/bin");
# Path to the systemd store path of the new system
my $new_systemd = "@systemd@";
# To be robust against interruption, record what units need to be started etc.
# We read these files again every time this script starts to make sure we continue
# where the old (interrupted) script left off.
my $start_list_file = "/run/nixos/start-list";
my $restart_list_file = "/run/nixos/restart-list";
my $reload_list_file = "/run/nixos/reload-list";
# Parse restart/reload requests by the activation script.
# Activation scripts may write newline-separated units to the restart
# file and switch-to-configuration will handle them. While
# `stopIfChanged = true` is ignored, switch-to-configuration will
# handle `restartIfChanged = false` and `reloadIfChanged = true`.
# This is the same as specifying a restart trigger in the NixOS module.
#
# The reload file asks the script to reload a unit. This is the same as
# specifying a reload trigger in the NixOS module and can be ignored if
# the unit is restarted in this activation.
my $restart_by_activation_file = "/run/nixos/activation-restart-list";
my $reload_by_activation_file = "/run/nixos/activation-reload-list";
my $dry_restart_by_activation_file = "/run/nixos/dry-activation-restart-list";
my $dry_reload_by_activation_file = "/run/nixos/dry-activation-reload-list";
# The action that is to be performed (like switch, boot, test, dry-activate)
# Also exposed via environment variable from now on
my $action = shift(@ARGV);
$ENV{NIXOS_ACTION} = $action;
# Expose the locale archive as an environment variable for systemctl and the activation script
if ("@localeArchive@" ne "") {
$ENV{LOCALE_ARCHIVE} = "@localeArchive@";
}
if (!defined($action) || ($action ne "switch" && $action ne "boot" && $action ne "test" && $action ne "dry-activate")) {
print STDERR <<"EOF";
Usage: $0 [switch|boot|test]
switch: make the configuration the boot default and activate now
boot: make the configuration the boot default
test: activate the configuration, but don\'t make it the boot default
dry-activate: show what would be done if this configuration were activated
EOF
exit(1);
}
# This is a NixOS installation if it has /etc/NIXOS or a proper
# /etc/os-release.
if (!-f "/etc/NIXOS" && (read_file("/etc/os-release", err_mode => "quiet") // "") !~ /^ID="?nixos"?/msx) {
die("This is not a NixOS installation!\n");
}
make_path("/run/nixos", { mode => oct(755) });
openlog("nixos", "", LOG_USER);
# Install or update the bootloader.
if ($action eq "switch" || $action eq "boot") {
chomp(my $install_boot_loader = <<'EOFBOOTLOADER');
@installBootLoader@
EOFBOOTLOADER
system("$install_boot_loader $out") == 0 or exit 1;
}
# Just in case the new configuration hangs the system, do a sync now.
if (($ENV{"NIXOS_NO_SYNC"} // "") ne "1") {
system("@coreutils@/bin/sync", "-f", "/nix/store");
}
if ($action eq "boot") {
exit(0);
}
# Check if we can activate the new configuration.
my $cur_init_interface_version = read_file("/run/current-system/init-interface-version", err_mode => "quiet") // "";
my $new_init_interface_version = read_file("$out/init-interface-version");
if ($new_init_interface_version ne $cur_init_interface_version) {
print STDERR <<'EOF';
Warning: the new NixOS configuration has an ‘init’ that is
incompatible with the current configuration. The new configuration
won't take effect until you reboot the system.
EOF
exit(100);
}
# Ignore SIGHUP so that we're not killed if we're running on (say)
# virtual console 1 and we restart the "tty1" unit.
$SIG{PIPE} = "IGNORE";
# Replacement for Net::DBus that calls busctl of the current systemd, parses
# it's json output and returns the response using only core modules to reduce
# dependencies on perlPackages in baseSystem
sub busctl_call_systemd1_mgr {
my (@args) = @_;
my $cmd = [
"$cur_systemd/busctl", "--json=short", "call", "org.freedesktop.systemd1",
"/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager",
@args
];
my ($ok, $err, undef, $stdout) = IPC::Cmd::run(command => $cmd);
die $err unless $ok;
my $res = decode_json(join "", @$stdout);
return $res;
}
# Asks the currently running systemd instance via dbus which units are active.
# Returns a hash where the key is the name of each unit and the value a hash
# of load, state, substate.
sub get_active_units {
my $units = busctl_call_systemd1_mgr("ListUnitsByPatterns", "asas", 0, 0)->{data}->[0];
my $res = {};
for my $item (@{$units}) {
my ($id, $description, $load_state, $active_state, $sub_state,
$following, $unit_path, $job_id, $job_type, $job_path) = @{$item};
if ($following ne "") {
next;
}
if ($job_id == 0 and $active_state eq "inactive") {
next;
}
$res->{$id} = { load => $load_state, state => $active_state, substate => $sub_state };
}
return $res;
}
# Asks the currently running systemd instance whether a unit is currently active.
# Takes the name of the unit as an argument and returns a bool whether the unit is active or not.
sub unit_is_active {
my ($unit_name) = @_;
my $units = busctl_call_systemd1_mgr("ListUnitsByNames", "as", 1, , "--", $unit_name)->{data}->[0];
if (scalar(@{$units}) == 0) {
return 0;
}
my $active_state = $units->[0]->[3];
return $active_state eq "active" || $active_state eq "activating";
}
# Parse a fstab file, given its path.
# Returns a tuple of filesystems and swaps.
#
# Filesystems is a hash of mountpoint and { device, fsType, options }
# Swaps is a hash of device and { options }
sub parse_fstab {
my ($filename) = @_;
my ($fss, $swaps);
foreach my $line (read_file($filename, err_mode => "quiet")) {
chomp($line);
$line =~ s/^\s*\#.*//msx;
if ($line =~ /^\s*$/msx) {
next;
}
my @xs = split(/\s+/msx, $line);
if ($xs[2] eq "swap") {
$swaps->{$xs[0]} = { options => $xs[3] // "" };
} else {
$fss->{$xs[1]} = { device => $xs[0], fsType => $xs[2], options => $xs[3] // "" };
}
}
return ($fss, $swaps);
}
# This subroutine takes a single ini file that specified systemd configuration
# like unit configuration and parses it into a hash where the keys are the sections
# of the unit file and the values are hashes themselves. These hashes have the unit file
# keys as their keys (left side of =) and an array of all values that were set as their
# values. If a value is empty (for example `ExecStart=`), then all current definitions are
# removed.
#
# Instead of returning the hash, this subroutine takes a hashref to return the data in. This
# allows calling the subroutine multiple times with the same hash to parse override files.
sub parse_systemd_ini {
my ($unit_contents, $path) = @_;
# Tie the ini file to a hash for easier access
tie(my %file_contents, "Config::IniFiles", (-file => $path, -allowempty => 1, -allowcontinue => 1)); ## no critic(Miscellanea::ProhibitTies)
# Copy over all sections
foreach my $section_name (keys(%file_contents)) {
if ($section_name eq "Install") {
# Skip the [Install] section because it has no relevant keys for us
next;
}
# Copy over all keys
foreach my $ini_key (keys(%{$file_contents{$section_name}})) {
# Ensure the value is an array so it's easier to work with
my $ini_value = $file_contents{$section_name}{$ini_key};
my @ini_values;
if (ref($ini_value) eq "ARRAY") {
@ini_values = @{$ini_value};
} else {
@ini_values = $ini_value;
}
# Go over all values
for my $ini_value (@ini_values) {
# If a value is empty, it's an override that tells us to clean the value
if ($ini_value eq "") {
delete $unit_contents->{$section_name}->{$ini_key};
next;
}
push(@{$unit_contents->{$section_name}->{$ini_key}}, $ini_value);
}
}
}
return;
}
# This subroutine takes the path to a systemd configuration file (like a unit configuration),
# parses it, and returns a hash that contains the contents. The contents of this hash are
# explained in the `parse_systemd_ini` subroutine. Neither the sections nor the keys inside
# the sections are consistently sorted.
#
# If a directory with the same basename ending in .d exists next to the unit file, it will be
# assumed to contain override files which will be parsed as well and handled properly.
sub parse_unit {
my ($unit_path) = @_;
# Parse the main unit and all overrides
my %unit_data;
# Replace \ with \\ so glob() still works with units that have a \ in them
# Valid characters in unit names are ASCII letters, digits, ":", "-", "_", ".", and "\"
$unit_path =~ s/\\/\\\\/gmsx;
foreach (glob("${unit_path}{,.d/*.conf}")) {
parse_systemd_ini(\%unit_data, "$_")
}
return %unit_data;
}
# Checks whether a specified boolean in a systemd unit is true
# or false, with a default that is applied when the value is not set.
sub parse_systemd_bool {
my ($unit_config, $section_name, $bool_name, $default) = @_;
my @values = @{$unit_config->{$section_name}{$bool_name} // []};
# Return default if value is not set
if ((scalar(@values) < 1) || (not defined($values[-1]))) {
return $default;
}
# If value is defined multiple times, use the last definition
my $last_value = $values[-1];
# These are valid values as of systemd.syntax(7)
return $last_value eq "1" || $last_value eq "yes" || $last_value eq "true" || $last_value eq "on";
}
# Writes a unit name into a given file to be more resilient against
# crashes of the script. Does nothing when the action is dry-activate.
sub record_unit {
my ($fn, $unit) = @_;
if ($action ne "dry-activate") {
write_file($fn, { append => 1 }, "$unit\n");
}
return;
}
# The opposite of record_unit, removes a unit name from a file
sub unrecord_unit {
my ($fn, $unit) = @_;
if ($action ne "dry-activate") {
edit_file(sub { s/^$unit\n//msx }, $fn);
}
return;
}
# Compare the contents of two unit files and return whether the unit
# needs to be restarted or reloaded. If the units differ, the service
# is restarted unless the only difference is `X-Reload-Triggers` in the
# `Unit` section. If this is the only modification, the unit is reloaded
# instead of restarted.
# Returns:
# - 0 if the units are equal
# - 1 if the units are different and a restart action is required
# - 2 if the units are different and a reload action is required
sub compare_units { ## no critic(Subroutines::ProhibitExcessComplexity)
my ($cur_unit, $new_unit) = @_;
my $ret = 0;
# Keys to ignore in the [Unit] section
my %unit_section_ignores = map { $_ => 1 } qw(
X-Reload-Triggers
Description Documentation
OnFailure OnSuccess OnFailureJobMode
IgnoreOnIsolate StopWhenUnneeded
RefuseManualStart RefuseManualStop
AllowIsolate CollectMode
SourcePath
);
my $comp_array = sub {
my ($a, $b) = @_;
return join("\0", @{$a}) eq join("\0", @{$b});
};
# Comparison hash for the sections
my %section_cmp = map { $_ => 1 } keys(%{$new_unit});
# Iterate over the sections
foreach my $section_name (keys(%{$cur_unit})) {
# Missing section in the new unit?
if (not exists($section_cmp{$section_name})) {
# If the [Unit] section was removed, make sure that only keys
# were in it that are ignored
if ($section_name eq "Unit") {
foreach my $ini_key (keys(%{$cur_unit->{"Unit"}})) {
if (not defined($unit_section_ignores{$ini_key})) {
return 1;
}
}
next; # check the next section
} else {
return 1;
}
if ($section_name eq "Unit" and %{$cur_unit->{"Unit"}} == 1 and defined(%{$cur_unit->{"Unit"}}{"X-Reload-Triggers"})) {
# If a new [Unit] section was removed that only contained X-Reload-Triggers,
# do nothing.
next;
} else {
return 1;
}
}
delete $section_cmp{$section_name};
# Comparison hash for the section contents
my %ini_cmp = map { $_ => 1 } keys(%{$new_unit->{$section_name}});
# Iterate over the keys of the section
foreach my $ini_key (keys(%{$cur_unit->{$section_name}})) {
delete $ini_cmp{$ini_key};
my @cur_value = @{$cur_unit->{$section_name}{$ini_key}};
# If the key is missing in the new unit, they are different...
if (not $new_unit->{$section_name}{$ini_key}) {
# ... unless the key that is now missing is one of the ignored keys
if ($section_name eq "Unit" and defined($unit_section_ignores{$ini_key})) {
next;
}
return 1;
}
my @new_value = @{$new_unit->{$section_name}{$ini_key}};
# If the contents are different, the units are different
if (not $comp_array->(\@cur_value, \@new_value)) {
# Check if only the reload triggers changed or one of the ignored keys
if ($section_name eq "Unit") {
if ($ini_key eq "X-Reload-Triggers") {
$ret = 2;
next;
} elsif (defined($unit_section_ignores{$ini_key})) {
next;
}
}
return 1;
}
}
# A key was introduced that was missing in the previous unit
if (%ini_cmp) {
if ($section_name eq "Unit") {
foreach my $ini_key (keys(%ini_cmp)) {
if ($ini_key eq "X-Reload-Triggers") {
$ret = 2;
} elsif (defined($unit_section_ignores{$ini_key})) {
next;
} else {
return 1;
}
}
} else {
return 1;
}
};
}
# A section was introduced that was missing in the previous unit
if (%section_cmp) {
if (%section_cmp == 1 and defined($section_cmp{"Unit"})) {
foreach my $ini_key (keys(%{$new_unit->{"Unit"}})) {
if (not defined($unit_section_ignores{$ini_key})) {
return 1;
} elsif ($ini_key eq "X-Reload-Triggers") {
$ret = 2;
}
}
} else {
return 1;
}
}
return $ret;
}
# Called when a unit exists in both the old systemd and the new system and the units
# differ. This figures out of what units are to be stopped, restarted, reloaded, started, and skipped.
sub handle_modified_unit { ## no critic(Subroutines::ProhibitManyArgs, Subroutines::ProhibitExcessComplexity)
my ($unit, $base_name, $new_unit_file, $new_unit_info, $active_cur, $units_to_stop, $units_to_start, $units_to_reload, $units_to_restart, $units_to_skip) = @_;
if ($unit eq "sysinit.target" || $unit eq "basic.target" || $unit eq "multi-user.target" || $unit eq "graphical.target" || $unit =~ /\.path$/msx || $unit =~ /\.slice$/msx) {
# Do nothing. These cannot be restarted directly.
# Slices and Paths don't have to be restarted since
# properties (resource limits and inotify watches)
# seem to get applied on daemon-reload.
} elsif ($unit =~ /\.mount$/msx) {
# Reload the changed mount unit to force a remount.
# FIXME: only reload when Options= changed, restart otherwise
$units_to_reload->{$unit} = 1;
record_unit($reload_list_file, $unit);
} elsif ($unit =~ /\.socket$/msx) {
# FIXME: do something?
# Attempt to fix this: https://github.com/NixOS/nixpkgs/pull/141192
# Revert of the attempt: https://github.com/NixOS/nixpkgs/pull/147609
# More details: https://github.com/NixOS/nixpkgs/issues/74899#issuecomment-981142430
} else {
my %new_unit_info = $new_unit_info ? %{$new_unit_info} : parse_unit($new_unit_file);
if (parse_systemd_bool(\%new_unit_info, "Service", "X-ReloadIfChanged", 0) and not $units_to_restart->{$unit} and not $units_to_stop->{$unit}) {
$units_to_reload->{$unit} = 1;
record_unit($reload_list_file, $unit);
}
elsif (!parse_systemd_bool(\%new_unit_info, "Service", "X-RestartIfChanged", 1) || parse_systemd_bool(\%new_unit_info, "Unit", "RefuseManualStop", 0) || parse_systemd_bool(\%new_unit_info, "Unit", "X-OnlyManualStart", 0)) {
$units_to_skip->{$unit} = 1;
} else {
# It doesn't make sense to stop and start non-services because
# they can't have ExecStop=
if (!parse_systemd_bool(\%new_unit_info, "Service", "X-StopIfChanged", 1) || $unit !~ /\.service$/msx) {
# This unit should be restarted instead of
# stopped and started.
$units_to_restart->{$unit} = 1;
record_unit($restart_list_file, $unit);
# Remove from units to reload so we don't restart and reload
if ($units_to_reload->{$unit}) {
delete $units_to_reload->{$unit};
unrecord_unit($reload_list_file, $unit);
}
} else {
# If this unit is socket-activated, then stop the
# socket unit(s) as well, and restart the
# socket(s) instead of the service.
my $socket_activated = 0;
if ($unit =~ /\.service$/msx) {
my @sockets = split(/\s+/msx, join(" ", @{$new_unit_info{Service}{Sockets} // []}));
if (scalar(@sockets) == 0) {
@sockets = ("$base_name.socket");
}
foreach my $socket (@sockets) {
if (defined($active_cur->{$socket})) {
# We can now be sure this is a socket-activate unit
$units_to_stop->{$socket} = 1;
# Only restart sockets that actually
# exist in new configuration:
if (-e "$out/etc/systemd/system/$socket") {
$units_to_start->{$socket} = 1;
if ($units_to_start eq $units_to_restart) {
record_unit($restart_list_file, $socket);
} else {
record_unit($start_list_file, $socket);
}
$socket_activated = 1;
}
# Remove from units to reload so we don't restart and reload
if ($units_to_reload->{$unit}) {
delete $units_to_reload->{$unit};
unrecord_unit($reload_list_file, $unit);
}
}
}
}
# If the unit is not socket-activated, record
# that this unit needs to be started below.
# We write this to a file to ensure that the
# service gets restarted if we're interrupted.
if (!$socket_activated) {
$units_to_start->{$unit} = 1;
if ($units_to_start eq $units_to_restart) {
record_unit($restart_list_file, $unit);
} else {
record_unit($start_list_file, $unit);
}
}
$units_to_stop->{$unit} = 1;
# Remove from units to reload so we don't restart and reload
if ($units_to_reload->{$unit}) {
delete $units_to_reload->{$unit};
unrecord_unit($reload_list_file, $unit);
}
}
}
}
return;
}
# Figure out what units need to be stopped, started, restarted or reloaded.
my (%units_to_stop, %units_to_skip, %units_to_start, %units_to_restart, %units_to_reload);
my %units_to_filter; # units not shown
%units_to_start = map { $_ => 1 }
split(/\n/msx, read_file($start_list_file, err_mode => "quiet") // "");
%units_to_restart = map { $_ => 1 }
split(/\n/msx, read_file($restart_list_file, err_mode => "quiet") // "");
%units_to_reload = map { $_ => 1 }
split(/\n/msx, read_file($reload_list_file, err_mode => "quiet") // "");
my $active_cur = get_active_units();
while (my ($unit, $state) = each(%{$active_cur})) {
my $base_unit = $unit;
my $cur_unit_file = "/etc/systemd/system/$base_unit";
my $new_unit_file = "$out/etc/systemd/system/$base_unit";
# Detect template instances.
if (!-e $cur_unit_file && !-e $new_unit_file && $unit =~ /^(.*)@[^\.]*\.(.*)$/msx) {
$base_unit = "$1\@.$2";
$cur_unit_file = "/etc/systemd/system/$base_unit";
$new_unit_file = "$out/etc/systemd/system/$base_unit";
}
my $base_name = $base_unit;
$base_name =~ s/\.[[:lower:]]*$//msx;
if (-e $cur_unit_file && ($state->{state} eq "active" || $state->{state} eq "activating")) {
if (! -e $new_unit_file || abs_path($new_unit_file) eq "/dev/null") {
my %cur_unit_info = parse_unit($cur_unit_file);
if (parse_systemd_bool(\%cur_unit_info, "Unit", "X-StopOnRemoval", 1)) {
$units_to_stop{$unit} = 1;
}
}
elsif ($unit =~ /\.target$/msx) {
my %new_unit_info = parse_unit($new_unit_file);
# Cause all active target units to be restarted below.
# This should start most changed units we stop here as
# well as any new dependencies (including new mounts and
# swap devices). FIXME: the suspend target is sometimes
# active after the system has resumed, which probably
# should not be the case. Just ignore it.
if ($unit ne "suspend.target" && $unit ne "hibernate.target" && $unit ne "hybrid-sleep.target") {
if (!(parse_systemd_bool(\%new_unit_info, "Unit", "RefuseManualStart", 0) || parse_systemd_bool(\%new_unit_info, "Unit", "X-OnlyManualStart", 0))) {
$units_to_start{$unit} = 1;
record_unit($start_list_file, $unit);
# Don't spam the user with target units that always get started.
$units_to_filter{$unit} = 1;
}
}
# Stop targets that have X-StopOnReconfiguration set.
# This is necessary to respect dependency orderings
# involving targets: if unit X starts after target Y and
# target Y starts after unit Z, then if X and Z have both
# changed, then X should be restarted after Z. However,
# if target Y is in the "active" state, X and Z will be
# restarted at the same time because X's dependency on Y
# is already satisfied. Thus, we need to stop Y first.
# Stopping a target generally has no effect on other units
# (unless there is a PartOf dependency), so this is just a
# bookkeeping thing to get systemd to do the right thing.
if (parse_systemd_bool(\%new_unit_info, "Unit", "X-StopOnReconfiguration", 0)) {
$units_to_stop{$unit} = 1;
}
}
else {
my %cur_unit_info = parse_unit($cur_unit_file);
my %new_unit_info = parse_unit($new_unit_file);
my $diff = compare_units(\%cur_unit_info, \%new_unit_info);
if ($diff == 1) {
handle_modified_unit($unit, $base_name, $new_unit_file, \%new_unit_info, $active_cur, \%units_to_stop, \%units_to_start, \%units_to_reload, \%units_to_restart, \%units_to_skip);
} elsif ($diff == 2 and not $units_to_restart{$unit}) {
$units_to_reload{$unit} = 1;
record_unit($reload_list_file, $unit);
}
}
}
}
# Converts a path to the name of a systemd mount unit that would be responsible
# for mounting this path.
sub path_to_unit_name {
my ($path) = @_;
# Use current version of systemctl binary before daemon is reexeced.
open(my $cmd, "-|", "$cur_systemd/systemd-escape", "--suffix=mount", "-p", $path)
or die "Unable to escape $path!\n";
my $escaped = do { local $/ = undef; <$cmd> };
chomp($escaped);
close($cmd) or die("Unable to close systemd-escape pipe");
return $escaped;
}
# Compare the previous and new fstab to figure out which filesystems
# need a remount or need to be unmounted. New filesystems are mounted
# automatically by starting local-fs.target. FIXME: might be nicer if
# we generated units for all mounts; then we could unify this with the
# unit checking code above.
my ($cur_fss, $cur_swaps) = parse_fstab("/etc/fstab");
my ($new_fss, $new_swaps) = parse_fstab("$out/etc/fstab");
foreach my $mount_point (keys(%{$cur_fss})) {
my $cur = $cur_fss->{$mount_point};
my $new = $new_fss->{$mount_point};
my $unit = path_to_unit_name($mount_point);
if (!defined($new)) {
# Filesystem entry disappeared, so unmount it.
$units_to_stop{$unit} = 1;
} elsif ($cur->{fsType} ne $new->{fsType} || $cur->{device} ne $new->{device}) {
# Filesystem type or device changed, so unmount and mount it.
$units_to_stop{$unit} = 1;
$units_to_start{$unit} = 1;
record_unit($start_list_file, $unit);
} elsif ($cur->{options} ne $new->{options}) {
# Mount options changes, so remount it.
$units_to_reload{$unit} = 1;
record_unit($reload_list_file, $unit);
}
}
# Also handles swap devices.
foreach my $device (keys(%{$cur_swaps})) {
my $cur = $cur_swaps->{$device};
my $new = $new_swaps->{$device};
if (!defined($new)) {
# Swap entry disappeared, so turn it off. Can't use
# "systemctl stop" here because systemd has lots of alias
# units that prevent a stop from actually calling
# "swapoff".
if ($action ne "dry-activate") {
print STDERR "would stop swap device: $device\n";
} else {
print STDERR "stopping swap device: $device\n";
system("@utillinux@/sbin/swapoff", $device);
}
}
# FIXME: update swap options (i.e. its priority).
}
# Should we have systemd re-exec itself?
my $cur_pid1_path = abs_path("/proc/1/exe") // "/unknown";
my $cur_systemd_system_config = abs_path("/etc/systemd/system.conf") // "/unknown";
my $new_pid1_path = abs_path("$new_systemd/lib/systemd/systemd") or die;
my $new_systemd_system_config = abs_path("$out/etc/systemd/system.conf") // "/unknown";
my $restart_systemd = $cur_pid1_path ne $new_pid1_path;
if ($cur_systemd_system_config ne $new_systemd_system_config) {
$restart_systemd = 1;
}
# Takes an array of unit names and returns an array with the same elements,
# except all units that are also in the global variable `unitsToFilter`.
sub filter_units {
my ($units) = @_;
my @res;
foreach my $unit (sort(keys(%{$units}))) {
if (!defined($units_to_filter{$unit})) {
push(@res, $unit);
}
}
return @res;
}
my @units_to_stop_filtered = filter_units(\%units_to_stop);
# Show dry-run actions.
if ($action eq "dry-activate") {
if (scalar(@units_to_stop_filtered) > 0) {
print STDERR "would stop the following units: ", join(", ", @units_to_stop_filtered), "\n";
}
if (scalar(keys(%units_to_skip)) > 0) {
print STDERR "would NOT stop the following changed units: ", join(", ", sort(keys(%units_to_skip))), "\n";
}
print STDERR "would activate the configuration...\n";
system("$out/dry-activate", "$out");
# Handle the activation script requesting the restart or reload of a unit.
foreach (split(/\n/msx, read_file($dry_restart_by_activation_file, err_mode => "quiet") // "")) {
my $unit = $_;
my $base_unit = $unit;
my $new_unit_file = "$out/etc/systemd/system/$base_unit";
# Detect template instances.
if (!-e $new_unit_file && $unit =~ /^(.*)@[^\.]*\.(.*)$/msx) {
$base_unit = "$1\@.$2";
$new_unit_file = "$out/etc/systemd/system/$base_unit";
}
my $base_name = $base_unit;
$base_name =~ s/\.[[:lower:]]*$//msx;
# Start units if they were not active previously
if (not defined($active_cur->{$unit})) {
$units_to_start{$unit} = 1;
next;
}
handle_modified_unit($unit, $base_name, $new_unit_file, undef, $active_cur, \%units_to_restart, \%units_to_restart, \%units_to_reload, \%units_to_restart, \%units_to_skip);
}
unlink($dry_restart_by_activation_file);
foreach (split(/\n/msx, read_file($dry_reload_by_activation_file, err_mode => "quiet") // "")) {
my $unit = $_;
if (defined($active_cur->{$unit}) and not $units_to_restart{$unit} and not $units_to_stop{$unit}) {
$units_to_reload{$unit} = 1;
record_unit($reload_list_file, $unit);
}
}
unlink($dry_reload_by_activation_file);
if ($restart_systemd) {
print STDERR "would restart systemd\n";
}
if (scalar(keys(%units_to_reload)) > 0) {
print STDERR "would reload the following units: ", join(", ", sort(keys(%units_to_reload))), "\n";
}
if (scalar(keys(%units_to_restart)) > 0) {
print STDERR "would restart the following units: ", join(", ", sort(keys(%units_to_restart))), "\n";
}
my @units_to_start_filtered = filter_units(\%units_to_start);
if (scalar(@units_to_start_filtered)) {
print STDERR "would start the following units: ", join(", ", @units_to_start_filtered), "\n";
}
exit 0;
}
syslog(LOG_NOTICE, "switching to system configuration $out");
if (scalar(keys(%units_to_stop)) > 0) {
if (scalar(@units_to_stop_filtered)) {
print STDERR "stopping the following units: ", join(", ", @units_to_stop_filtered), "\n";
}
# Use current version of systemctl binary before daemon is reexeced.
system("$cur_systemd/systemctl", "stop", "--", sort(keys(%units_to_stop)));
}
if (scalar(keys(%units_to_skip)) > 0) {
print STDERR "NOT restarting the following changed units: ", join(", ", sort(keys(%units_to_skip))), "\n";
}
# Activate the new configuration (i.e., update /etc, make accounts,
# and so on).
my $res = 0;
print STDERR "activating the configuration...\n";
system("$out/activate", "$out") == 0 or $res = 2;
# Handle the activation script requesting the restart or reload of a unit.
foreach (split(/\n/msx, read_file($restart_by_activation_file, err_mode => "quiet") // "")) {
my $unit = $_;
my $base_unit = $unit;
my $new_unit_file = "$out/etc/systemd/system/$base_unit";
# Detect template instances.
if (!-e $new_unit_file && $unit =~ /^(.*)@[^\.]*\.(.*)$/msx) {
$base_unit = "$1\@.$2";
$new_unit_file = "$out/etc/systemd/system/$base_unit";
}
my $base_name = $base_unit;
$base_name =~ s/\.[[:lower:]]*$//msx;
# Start units if they were not active previously
if (not defined($active_cur->{$unit})) {
$units_to_start{$unit} = 1;
record_unit($start_list_file, $unit);
next;
}
handle_modified_unit($unit, $base_name, $new_unit_file, undef, $active_cur, \%units_to_restart, \%units_to_restart, \%units_to_reload, \%units_to_restart, \%units_to_skip);
}
# We can remove the file now because it has been propagated to the other restart/reload files
unlink($restart_by_activation_file);
foreach (split(/\n/msx, read_file($reload_by_activation_file, err_mode => "quiet") // "")) {
my $unit = $_;
if (defined($active_cur->{$unit}) and not $units_to_restart{$unit} and not $units_to_stop{$unit}) {
$units_to_reload{$unit} = 1;
record_unit($reload_list_file, $unit);
}
}
# We can remove the file now because it has been propagated to the other reload file
unlink($reload_by_activation_file);
# Restart systemd if necessary. Note that this is done using the
# current version of systemd, just in case the new one has trouble
# communicating with the running pid 1.
if ($restart_systemd) {
print STDERR "restarting systemd...\n";
system("$cur_systemd/systemctl", "daemon-reexec") == 0 or $res = 2;
}
# Forget about previously failed services.
system("$new_systemd/bin/systemctl", "reset-failed");
# Make systemd reload its units.
system("$new_systemd/bin/systemctl", "daemon-reload") == 0 or $res = 3;
# Reload user units
open(my $list_active_users, "-|", "$new_systemd/bin/loginctl", "list-users", "--no-legend") || die("Unable to call loginctl");
while (my $f = <$list_active_users>) {
if ($f !~ /^\s*(?<uid>\d+)\s+(?<user>\S+)/msx) {
next;
}
my ($uid, $name) = ($+{uid}, $+{user});
print STDERR "reloading user units for $name...\n";
system("@su@", "-s", "@shell@", "-l", $name, "-c",
"export XDG_RUNTIME_DIR=/run/user/$uid; " .
"$cur_systemd/systemctl --user daemon-reexec; " .
"$new_systemd/bin/systemctl --user start nixos-activation.service");
}
close($list_active_users) || die("Unable to close the file handle to loginctl");
# Set the new tmpfiles
print STDERR "setting up tmpfiles\n";
system("$new_systemd/bin/systemd-tmpfiles", "--create", "--remove", "--exclude-prefix=/dev") == 0 or $res = 3;
# Before reloading we need to ensure that the units are still active. They may have been
# deactivated because one of their requirements got stopped. If they are inactive
# but should have been reloaded, the user probably expects them to be started.
if (scalar(keys(%units_to_reload)) > 0) {
for my $unit (keys(%units_to_reload)) {
if (!unit_is_active($unit)) {
# Figure out if we need to start the unit
my %unit_info = parse_unit("$out/etc/systemd/system/$unit");
if (!(parse_systemd_bool(\%unit_info, "Unit", "RefuseManualStart", 0) || parse_systemd_bool(\%unit_info, "Unit", "X-OnlyManualStart", 0))) {
$units_to_start{$unit} = 1;
record_unit($start_list_file, $unit);
}
# Don't reload the unit, reloading would fail
delete %units_to_reload{$unit};
unrecord_unit($reload_list_file, $unit);
}
}
}
# Reload units that need it. This includes remounting changed mount
# units.
if (scalar(keys(%units_to_reload)) > 0) {
print STDERR "reloading the following units: ", join(", ", sort(keys(%units_to_reload))), "\n";
system("$new_systemd/bin/systemctl", "reload", "--", sort(keys(%units_to_reload))) == 0 or $res = 4;
unlink($reload_list_file);
}
# Restart changed services (those that have to be restarted rather
# than stopped and started).
if (scalar(keys(%units_to_restart)) > 0) {
print STDERR "restarting the following units: ", join(", ", sort(keys(%units_to_restart))), "\n";
system("$new_systemd/bin/systemctl", "restart", "--", sort(keys(%units_to_restart))) == 0 or $res = 4;
unlink($restart_list_file);
}
# Start all active targets, as well as changed units we stopped above.
# The latter is necessary because some may not be dependencies of the
# targets (i.e., they were manually started). FIXME: detect units
# that are symlinks to other units. We shouldn't start both at the
# same time because we'll get a "Failed to add path to set" error from
# systemd.
my @units_to_start_filtered = filter_units(\%units_to_start);
if (scalar(@units_to_start_filtered)) {
print STDERR "starting the following units: ", join(", ", @units_to_start_filtered), "\n"
}
system("$new_systemd/bin/systemctl", "start", "--", sort(keys(%units_to_start))) == 0 or $res = 4;
unlink($start_list_file);
# Print failed and new units.
my (@failed, @new);
my $active_new = get_active_units();
while (my ($unit, $state) = each(%{$active_new})) {
if ($state->{state} eq "failed") {
push(@failed, $unit);
next;
}
if ($state->{substate} eq "auto-restart") {
# A unit in auto-restart substate is a failure *if* it previously failed to start
open(my $main_status_fd, "-|", "$new_systemd/bin/systemctl", "show", "--value", "--property=ExecMainStatus", $unit) || die("Unable to call 'systemctl show'");
my $main_status = do { local $/ = undef; <$main_status_fd> };
close($main_status_fd) || die("Unable to close 'systemctl show' fd");
chomp($main_status);
if ($main_status ne "0") {
push(@failed, $unit);
next;
}
}
# Ignore scopes since they are not managed by this script but rather
# created and managed by third-party services via the systemd dbus API.
# This only lists units that are not failed (including ones that are in auto-restart but have not failed previously)
if ($state->{state} ne "failed" && !defined($active_cur->{$unit}) && $unit !~ /\.scope$/msx) {
push(@new, $unit);
}
}
if (scalar(@new) > 0) {
print STDERR "the following new units were started: ", join(", ", sort(@new)), "\n"
}
if (scalar(@failed) > 0) {
my @failed_sorted = sort(@failed);
print STDERR "warning: the following units failed: ", join(", ", @failed_sorted), "\n\n";
system("$new_systemd/bin/systemctl status --no-pager --full '" . join("' '", @failed_sorted) . "' >&2");
$res = 4;
}
if ($res == 0) {
syslog(LOG_NOTICE, "finished switching to system configuration $out");
} else {
syslog(LOG_ERR, "switching to system configuration $out failed (status $res)");
}
exit($res);