diff options
Diffstat (limited to 'nixpkgs/nixos/modules/system/activation/switch-to-configuration.pl')
| -rw-r--r-- | nixpkgs/nixos/modules/system/activation/switch-to-configuration.pl | 500 |
1 files changed, 500 insertions, 0 deletions
diff --git a/nixpkgs/nixos/modules/system/activation/switch-to-configuration.pl b/nixpkgs/nixos/modules/system/activation/switch-to-configuration.pl new file mode 100644 index 000000000000..397b308b7311 --- /dev/null +++ b/nixpkgs/nixos/modules/system/activation/switch-to-configuration.pl @@ -0,0 +1,500 @@ +#! @perl@ + +use strict; +use warnings; +use File::Basename; +use File::Slurp; +use Net::DBus; +use Sys::Syslog qw(:standard :macros); +use Cwd 'abs_path'; + +my $out = "@out@"; + +# To be robust against interruption, record what units need to be started etc. +my $startListFile = "/run/systemd/start-list"; +my $restartListFile = "/run/systemd/restart-list"; +my $reloadListFile = "/run/systemd/reload-list"; + +my $action = shift @ARGV; + +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: $0 [switch|boot|test] + +switch: make the configuration the boot default and activate now +boot: make the configuration the boot default +test: activate the configuration, but don\'t make it the boot default +dry-activate: show what would be done if this configuration were activated +EOF + exit 1; +} + +# This is a NixOS installation if it has /etc/NIXOS or a proper +# /etc/os-release. +die "This is not a NixOS installation!\n" unless + -f "/etc/NIXOS" || (read_file("/etc/os-release", err_mode => 'quiet') // "") =~ /ID=nixos/s; + +openlog("nixos", "", LOG_USER); + +# Install or update the bootloader. +if ($action eq "switch" || $action eq "boot") { + system("@installBootLoader@ $out") == 0 or exit 1; +} + +# Just in case the new configuration hangs the system, do a sync now. +system("@coreutils@/bin/sync", "-f", "/nix/store") unless ($ENV{"NIXOS_NO_SYNC"} // "") eq "1"; + +exit 0 if $action eq "boot"; + +# Check if we can activate the new configuration. +my $oldVersion = read_file("/run/current-system/init-interface-version", err_mode => 'quiet') // ""; +my $newVersion = read_file("$out/init-interface-version"); + +if ($newVersion ne $oldVersion) { + print STDERR <<EOF; +Warning: the new NixOS configuration has an ‘init’ that is +incompatible with the current configuration. The new configuration +won\'t take effect until you reboot the system. +EOF + exit 100; +} + +# Ignore SIGHUP so that we're not killed if we're running on (say) +# virtual console 1 and we restart the "tty1" unit. +$SIG{PIPE} = "IGNORE"; + +sub getActiveUnits { + my $mgr = Net::DBus->system->get_service("org.freedesktop.systemd1")->get_object("/org/freedesktop/systemd1"); + my $units = $mgr->ListUnitsByPatterns([], []); + 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; + next unless $following eq ''; + next if $job_id == 0 and $active_state eq 'inactive'; + $res->{$id} = { load => $load_state, state => $active_state, substate => $sub_state }; + } + return $res; +} + +sub parseFstab { + my ($filename) = @_; + my ($fss, $swaps); + foreach my $line (read_file($filename, err_mode => 'quiet')) { + chomp $line; + $line =~ s/^\s*#.*//; + next if $line =~ /^\s*$/; + my @xs = split / /, $line; + if ($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, $swaps); +} + +sub parseUnit { + my ($filename) = @_; + my $info = {}; + parseKeyValues($info, read_file($filename)) if -f $filename; + parseKeyValues($info, read_file("${filename}.d/overrides.conf")) if -f "${filename}.d/overrides.conf"; + return $info; +} + +sub parseKeyValues { + my $info = shift; + foreach my $line (@_) { + # FIXME: not quite correct. + $line =~ /^([^=]+)=(.*)$/ or next; + $info->{$1} = $2; + } +} + +sub boolIsTrue { + my ($s) = @_; + return $s eq "yes" || $s eq "true"; +} + +sub recordUnit { + my ($fn, $unit) = @_; + write_file($fn, { append => 1 }, "$unit\n") if $action ne "dry-activate"; +} + +# As a fingerprint for determining whether a unit has changed, we use +# its absolute path. If it has an override file, we append *its* +# absolute path as well. +sub fingerprintUnit { + my ($s) = @_; + return abs_path($s) . (-f "${s}.d/overrides.conf" ? " " . abs_path "${s}.d/overrides.conf" : ""); +} + +# Figure out what units need to be stopped, started, restarted or reloaded. +my (%unitsToStop, %unitsToSkip, %unitsToStart, %unitsToRestart, %unitsToReload); + +my %unitsToFilter; # units not shown + +$unitsToStart{$_} = 1 foreach + split('\n', read_file($startListFile, err_mode => 'quiet') // ""); + +$unitsToRestart{$_} = 1 foreach + split('\n', read_file($restartListFile, err_mode => 'quiet') // ""); + +$unitsToReload{$_} = 1 foreach + split '\n', read_file($reloadListFile, err_mode => 'quiet') // ""; + +my $activePrev = getActiveUnits; +while (my ($unit, $state) = each %{$activePrev}) { + my $baseUnit = $unit; + + my $prevUnitFile = "/etc/systemd/system/$baseUnit"; + my $newUnitFile = "$out/etc/systemd/system/$baseUnit"; + + # Detect template instances. + if (!-e $prevUnitFile && !-e $newUnitFile && $unit =~ /^(.*)@[^\.]*\.(.*)$/) { + $baseUnit = "$1\@.$2"; + $prevUnitFile = "/etc/systemd/system/$baseUnit"; + $newUnitFile = "$out/etc/systemd/system/$baseUnit"; + } + + my $baseName = $baseUnit; + $baseName =~ s/\.[a-z]*$//; + + if (-e $prevUnitFile && ($state->{state} eq "active" || $state->{state} eq "activating")) { + if (! -e $newUnitFile || abs_path($newUnitFile) eq "/dev/null") { + # Ignore (i.e. never stop) these units: + if ($unit eq "system.slice") { + # TODO: This can be removed a few months after 18.09 is out + # (i.e. after everyone switched away from 18.03). + # Problem: Restarting (stopping) system.slice would not only + # stop X11 but also most system units/services. We obviously + # don't want this happening to users when they switch from 18.03 + # to 18.09 or nixos-unstable. + # Reason: The following change in systemd: + # https://github.com/systemd/systemd/commit/d8e5a9338278d6602a0c552f01f298771a384798 + # The commit adds system.slice to the perpetual units, which + # means removing the unit file and adding it to the source code. + # This is done so that system.slice can't be stopped anymore but + # in our case it ironically would cause this script to stop + # system.slice because the unit was removed (and an older + # systemd version is still running). + next; + } + my $unitInfo = parseUnit($prevUnitFile); + $unitsToStop{$unit} = 1 if boolIsTrue($unitInfo->{'X-StopOnRemoval'} // "yes"); + } + + elsif ($unit =~ /\.target$/) { + my $unitInfo = parseUnit($newUnitFile); + + # 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" && $unit ne "hybrid-sleep.target") { + unless (boolIsTrue($unitInfo->{'RefuseManualStart'} // "no")) { + $unitsToStart{$unit} = 1; + recordUnit($startListFile, $unit); + # Don't spam the user with target units that always get started. + $unitsToFilter{$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 (boolIsTrue($unitInfo->{'X-StopOnReconfiguration'} // "no")) { + $unitsToStop{$unit} = 1; + } + } + + elsif (fingerprintUnit($prevUnitFile) ne fingerprintUnit($newUnitFile)) { + if ($unit eq "sysinit.target" || $unit eq "basic.target" || $unit eq "multi-user.target" || $unit eq "graphical.target") { + # Do nothing. These cannot be restarted directly. + } elsif ($unit =~ /\.mount$/) { + # Reload the changed mount unit to force a remount. + $unitsToReload{$unit} = 1; + recordUnit($reloadListFile, $unit); + } elsif ($unit =~ /\.socket$/ || $unit =~ /\.path$/ || $unit =~ /\.slice$/) { + # FIXME: do something? + } else { + my $unitInfo = parseUnit($newUnitFile); + if (boolIsTrue($unitInfo->{'X-ReloadIfChanged'} // "no")) { + $unitsToReload{$unit} = 1; + recordUnit($reloadListFile, $unit); + } + elsif (!boolIsTrue($unitInfo->{'X-RestartIfChanged'} // "yes") || boolIsTrue($unitInfo->{'RefuseManualStop'} // "no") ) { + $unitsToSkip{$unit} = 1; + } else { + if (!boolIsTrue($unitInfo->{'X-StopIfChanged'} // "yes")) { + # This unit should be restarted instead of + # stopped and started. + $unitsToRestart{$unit} = 1; + recordUnit($restartListFile, $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 $socketActivated = 0; + if ($unit =~ /\.service$/) { + my @sockets = split / /, ($unitInfo->{Sockets} // ""); + if (scalar @sockets == 0) { + @sockets = ("$baseName.socket"); + } + foreach my $socket (@sockets) { + if (defined $activePrev->{$socket}) { + $unitsToStop{$socket} = 1; + $unitsToStart{$socket} = 1; + recordUnit($startListFile, $socket); + $socketActivated = 1; + } + } + } + + # If the unit is not socket-activated, record + # that this unit needs to be started below. + # We write this to a file to ensure that the + # service gets restarted if we're interrupted. + if (!$socketActivated) { + $unitsToStart{$unit} = 1; + recordUnit($startListFile, $unit); + } + + $unitsToStop{$unit} = 1; + } + } + } + } + } +} + +sub pathToUnitName { + my ($path) = @_; + # Use current version of systemctl binary before daemon is reexeced. + open my $cmd, "-|", "/run/current-system/sw/bin/systemd-escape", "--suffix=mount", "-p", $path + or die "Unable to escape $path!\n"; + my $escaped = join "", <$cmd>; + chomp $escaped; + close $cmd or die; + return $escaped; +} + +sub unique { + my %seen; + my @res; + foreach my $name (@_) { + next if $seen{$name}; + $seen{$name} = 1; + push @res, $name; + } + return @res; +} + +# Compare the previous and new fstab to figure out which filesystems +# need a remount or need to be unmounted. New filesystems are mounted +# automatically by starting local-fs.target. FIXME: might be nicer if +# we generated units for all mounts; then we could unify this with the +# unit checking code above. +my ($prevFss, $prevSwaps) = parseFstab "/etc/fstab"; +my ($newFss, $newSwaps) = parseFstab "$out/etc/fstab"; +foreach my $mountPoint (keys %$prevFss) { + my $prev = $prevFss->{$mountPoint}; + my $new = $newFss->{$mountPoint}; + my $unit = pathToUnitName($mountPoint); + if (!defined $new) { + # Filesystem entry disappeared, so unmount it. + $unitsToStop{$unit} = 1; + } elsif ($prev->{fsType} ne $new->{fsType} || $prev->{device} ne $new->{device}) { + # Filesystem type or device changed, so unmount and mount it. + $unitsToStop{$unit} = 1; + $unitsToStart{$unit} = 1; + recordUnit($startListFile, $unit); + } elsif ($prev->{options} ne $new->{options}) { + # Mount options changes, so remount it. + $unitsToReload{$unit} = 1; + recordUnit($reloadListFile, $unit); + } +} + +# Also handles swap devices. +foreach my $device (keys %$prevSwaps) { + my $prev = $prevSwaps->{$device}; + my $new = $newSwaps->{$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". + 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 $prevSystemd = abs_path("/proc/1/exe") // "/unknown"; +my $newSystemd = abs_path("@systemd@/lib/systemd/systemd") or die; +my $restartSystemd = $prevSystemd ne $newSystemd; + + +sub filterUnits { + my ($units) = @_; + my @res; + foreach my $unit (sort(keys %{$units})) { + push @res, $unit if !defined $unitsToFilter{$unit}; + } + return @res; +} + +my @unitsToStopFiltered = filterUnits(\%unitsToStop); +my @unitsToStartFiltered = filterUnits(\%unitsToStart); + + +# Show dry-run actions. +if ($action eq "dry-activate") { + print STDERR "would stop the following units: ", join(", ", @unitsToStopFiltered), "\n" + if scalar @unitsToStopFiltered > 0; + print STDERR "would NOT stop the following changed units: ", join(", ", sort(keys %unitsToSkip)), "\n" + if scalar(keys %unitsToSkip) > 0; + print STDERR "would restart systemd\n" if $restartSystemd; + print STDERR "would restart the following units: ", join(", ", sort(keys %unitsToRestart)), "\n" + if scalar(keys %unitsToRestart) > 0; + print STDERR "would start the following units: ", join(", ", @unitsToStartFiltered), "\n" + if scalar @unitsToStartFiltered; + print STDERR "would reload the following units: ", join(", ", sort(keys %unitsToReload)), "\n" + if scalar(keys %unitsToReload) > 0; + exit 0; +} + + +syslog(LOG_NOTICE, "switching to system configuration $out"); + +if (scalar (keys %unitsToStop) > 0) { + print STDERR "stopping the following units: ", join(", ", @unitsToStopFiltered), "\n" + if scalar @unitsToStopFiltered; + # Use current version of systemctl binary before daemon is reexeced. + system("/run/current-system/sw/bin/systemctl", "stop", "--", sort(keys %unitsToStop)); # FIXME: ignore errors? +} + +print STDERR "NOT restarting the following changed units: ", join(", ", sort(keys %unitsToSkip)), "\n" + if scalar(keys %unitsToSkip) > 0; + +# 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 $res = 2; + +# Restart systemd if necessary. +if ($restartSystemd) { + print STDERR "restarting systemd...\n"; + system("@systemd@/bin/systemctl", "daemon-reexec") == 0 or $res = 2; +} + +# Forget about previously failed services. +system("@systemd@/bin/systemctl", "reset-failed"); + +# Make systemd reload its units. +system("@systemd@/bin/systemctl", "daemon-reload") == 0 or $res = 3; + +# Reload user units +open my $listActiveUsers, '-|', '@systemd@/bin/loginctl', 'list-users', '--no-legend'; +while (my $f = <$listActiveUsers>) { + next unless $f =~ /^\s*(?<uid>\d+)\s+(?<user>\S+)/; + my ($uid, $name) = ($+{uid}, $+{user}); + print STDERR "reloading user units for $name...\n"; + + system("@su@", "-s", "@shell@", "-l", $name, "-c", "XDG_RUNTIME_DIR=/run/user/$uid @systemd@/bin/systemctl --user daemon-reload"); + system("@su@", "-s", "@shell@", "-l", $name, "-c", "XDG_RUNTIME_DIR=/run/user/$uid @systemd@/bin/systemctl --user start nixos-activation.service"); +} + +close $listActiveUsers; + +# Set the new tmpfiles +print STDERR "setting up tmpfiles\n"; +system("@systemd@/bin/systemd-tmpfiles", "--create", "--remove", "--exclude-prefix=/dev") == 0 or $res = 3; + +# Reload units that need it. This includes remounting changed mount +# units. +if (scalar(keys %unitsToReload) > 0) { + print STDERR "reloading the following units: ", join(", ", sort(keys %unitsToReload)), "\n"; + system("@systemd@/bin/systemctl", "reload", "--", sort(keys %unitsToReload)) == 0 or $res = 4; + unlink($reloadListFile); +} + +# Restart changed services (those that have to be restarted rather +# than stopped and started). +if (scalar(keys %unitsToRestart) > 0) { + print STDERR "restarting the following units: ", join(", ", sort(keys %unitsToRestart)), "\n"; + system("@systemd@/bin/systemctl", "restart", "--", sort(keys %unitsToRestart)) == 0 or $res = 4; + unlink($restartListFile); +} + +# 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. +print STDERR "starting the following units: ", join(", ", @unitsToStartFiltered), "\n" + if scalar @unitsToStartFiltered; +system("@systemd@/bin/systemctl", "start", "--", sort(keys %unitsToStart)) == 0 or $res = 4; +unlink($startListFile); + + +# Print failed and new units. +my (@failed, @new, @restarting); +my $activeNew = getActiveUnits; +while (my ($unit, $state) = each %{$activeNew}) { + if ($state->{state} eq "failed") { + push @failed, $unit; + } + elsif ($state->{state} eq "auto-restart") { + # A unit in auto-restart state is a failure *if* it previously failed to start + my $lines = `@systemd@/bin/systemctl show '$unit'`; + my $info = {}; + parseKeyValues($info, split("\n", $lines)); + + if ($info->{ExecMainStatus} ne '0') { + push @failed, $unit; + } + } + elsif ($state->{state} ne "failed" && !defined $activePrev->{$unit}) { + push @new, $unit; + } +} + +print STDERR "the following new units were started: ", join(", ", sort(@new)), "\n" + if scalar @new > 0; + +if (scalar @failed > 0) { + print STDERR "warning: the following units failed: ", join(", ", sort(@failed)), "\n"; + foreach my $unit (@failed) { + print STDERR "\n"; + system("COLUMNS=1000 @systemd@/bin/systemctl status --no-pager '$unit' >&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; |