alioth/nixpkgs
3
0
Fork 0
forked from mirrors/nixpkgs
Code Releases Activity

nixos-rebuild: Add ‘dry-activate’ command

Browse source 
‘nixos-rebuild dry-activate’ builds the new configuration and then
prints what systemd services would be stopped, restarted etc. if the
configuration were actually activated. This could be extended later to
show other activation actions (like uids being deleted).

To prevent confusion, ‘nixos-rebuild dry-run’ has been renamed to
‘nixos-rebuild dry-build’.
This commit is contained in:
Eelco Dolstra 2015-03-09 16:23:23 +01:00
parent e8b33876af
commit a574065a81
3 changed files with 107 additions and 52 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

23
nixos/doc/manual/man-nixos-rebuild.xml
View file

@ -1,7 +1,7 @@
<refentry xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:xi="http://www.w3.org/2001/XInclude">
<refmeta>
<refentrytitle><command>nixos-rebuild</command></refentrytitle>
<manvolnum>8</manvolnum>
@ -22,7 +22,8 @@
<arg choice='plain'><option>boot</option></arg>
<arg choice='plain'><option>test</option></arg>
<arg choice='plain'><option>build</option></arg>
<arg choice='plain'><option>dry-run</option></arg>
<arg choice='plain'><option>dry-build</option></arg>
<arg choice='plain'><option>dry-activate</option></arg>
<arg choice='plain'><option>build-vm</option></arg>
<arg choice='plain'><option>build-vm-with-bootloader</option></arg>
</group>
@ -114,10 +115,22 @@ $ nix-build /path/to/nixpkgs/nixos -A system
</varlistentry>
<varlistentry>
<term><option>dry-run</option></term>
<term><option>dry-build</option></term>
<listitem>
<para>Simply show what store paths would be built or downloaded
by any of the operations above.</para>
<para>Show what store paths would be built or downloaded by any
of the operations above, but otherwise do nothing.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>dry-activate</option></term>
<listitem>
<para>Build the new configuration, but instead of activating it,
show what changes would be performed by the activation (i.e. by
<command>nixos-rebuild test</command>). For
instance, this command will print which systemd units would be
restarted. The list of changes is not guaranteed to be
complete.</para>
</listitem>
</varlistentry>

11
nixos/modules/installer/tools/nixos-rebuild.sh
View file

@ -26,7 +26,8 @@ while [ "$#" -gt 0 ]; do
--help)
showSyntax
;;
switch|boot|test|build|dry-run|build-vm|build-vm-with-bootloader)
switch|boot|test|build|dry-build|dry-run|dry-activate|build-vm|build-vm-with-bootloader)
if [ "$i" = dry-run ]; then i=dry-build; fi
action="$i"
;;
--install-grub)
@ -137,7 +138,7 @@ fi
# First build Nix, since NixOS may require a newer version than the
# current one.
if [ -n "$rollback" -o "$action" = dry-run ]; then
if [ -n "$rollback" -o "$action" = dry-build ]; then
buildNix=
fi
@ -180,7 +181,7 @@ if [ -n "$canRun" ]; then
fi
if [ "$action" = dry-run ]; then
if [ "$action" = dry-build ]; then
extraBuildFlags+=(--dry-run)
fi
@ -193,7 +194,7 @@ if [ -z "$rollback" ]; then
if [ "$action" = switch -o "$action" = boot ]; then
nix-env "${extraBuildFlags[@]}" -p "$profile" -f '<nixpkgs/nixos>' --set -A system
pathToConfig="$profile"
elif [ "$action" = test -o "$action" = build -o "$action" = dry-run ]; then
elif [ "$action" = test -o "$action" = build -o "$action" = dry-build -o "$action" = dry-activate ]; then
nix-build '<nixpkgs/nixos>' -A system -k "${extraBuildFlags[@]}" > /dev/null
pathToConfig=./result
elif [ "$action" = build-vm ]; then
@ -224,7 +225,7 @@ fi
# If we're not just building, then make the new configuration the boot
# default and/or activate it now.
if [ "$action" = switch -o "$action" = boot -o "$action" = test ]; then
if [ "$action" = switch -o "$action" = boot -o "$action" = test -o "$action" = dry-activate ]; then
if ! $pathToConfig/bin/switch-to-configuration "$action"; then
echo "warning: error(s) occured while switching to the new configuration" >&2
exit 1

125
nixos/modules/system/activation/switch-to-configuration.pl
View file

@ -9,19 +9,21 @@ 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 (!defined $action || ($action ne "switch" && $action ne "boot" && $action ne "test")) {
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
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;
}
@ -56,8 +58,6 @@ EOF
exit 100;
}
syslog(LOG_NOTICE, "switching to system configuration $out");
# 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";
@ -116,6 +116,11 @@ sub boolIsTrue {
return $s eq "yes" || $s eq "true";
}
sub recordUnit {
my ($fn, $unit) = @_;
write_file($fn, { append => 1 }, "$unit\n") if $action ne "dry-activate";
}
# As a fingerprint for determining whether a unit has changed, we use
# its absolute path. If it has an override file, we append *its*
# absolute path as well.
@ -124,9 +129,18 @@ sub fingerprintUnit {
return abs_path($s) . (-f "${s}.d/overrides.conf" ? " " . abs_path "${s}.d/overrides.conf" : "");
}
# Stop all services that no longer exist or have changed in the new
# configuration.
my (@unitsToStop, @unitsToSkip);
# Figure out what units need to be stopped, started, restarted or reloaded.
my (%unitsToStop, %unitsToSkip, %unitsToStart, %unitsToRestart, %unitsToReload);
$unitsToStart{$_} = 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 = $unit;
@ -141,7 +155,7 @@ while (my ($unit, $state) = each %{$activePrev}) {
if (-e $prevUnitFile && ($state->{state} eq "active" || $state->{state} eq "activating")) {
if (! -e $newUnitFile || abs_path($newUnitFile) eq "/dev/null") {
push @unitsToStop, $unit;
$unitsToStop{$unit} = 1;
}
elsif ($unit =~ /\.target$/) {
@ -155,7 +169,8 @@ while (my ($unit, $state) = each %{$activePrev}) {
# 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")) {
write_file($startListFile, { append => 1 }, "$unit\n");
$unitsToStart{$unit} = 1;
recordUnit($startListFile, $unit);
}
}
@ -171,7 +186,7 @@ while (my ($unit, $state) = each %{$activePrev}) {
# (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")) {
push @unitsToStop, $unit;
$unitsToStop{$unit} = 1;
}
}
@ -180,16 +195,18 @@ while (my ($unit, $state) = each %{$activePrev}) {
# Do nothing. These cannot be restarted directly.
} elsif ($unit =~ /\.mount$/) {
# Reload the changed mount unit to force a remount.
write_file($reloadListFile, { append => 1 }, "$unit\n");
$unitsToReload{$unit} = 1;
recordUnit($reloadListFile, $unit);
} elsif ($unit =~ /\.socket$/ || $unit =~ /\.path$/ || $unit =~ /\.slice$/) {
# FIXME: do something?
} else {
my $unitInfo = parseUnit($newUnitFile);
if (boolIsTrue($unitInfo->{'X-ReloadIfChanged'} // "no")) {
write_file($reloadListFile, { append => 1 }, "$unit\n");
$unitsToReload{$unit} = 1;
recordUnit($reloadListFile, $unit);
}
elsif (!boolIsTrue($unitInfo->{'X-RestartIfChanged'} // "yes") || boolIsTrue($unitInfo->{'RefuseManualStop'} // "no") ) {
push @unitsToSkip, $unit;
$unitsToSkip{$unit} = 1;
} else {
# If this unit is socket-activated, then stop the
# socket unit(s) as well, and restart the
@ -202,8 +219,9 @@ while (my ($unit, $state) = each %{$activePrev}) {
}
foreach my $socket (@sockets) {
if (defined $activePrev->{$socket}) {
push @unitsToStop, $socket;
write_file($startListFile, { append => 1 }, "$socket\n");
$unitsToStop{$unit} = 1;
$unitsToStart{$unit} = 1;
recordUnit($startListFile, $socket);
$socketActivated = 1;
}
}
@ -213,7 +231,8 @@ while (my ($unit, $state) = each %{$activePrev}) {
# This unit should be restarted instead of
# stopped and started.
write_file($restartListFile, { append => 1 }, "$unit\n");
$unitsToRestart{$unit} = 1;
recordUnit($restartListFile, $unit);
} else {
@ -222,10 +241,11 @@ while (my ($unit, $state) = each %{$activePrev}) {
# We write this to a file to ensure that the
# service gets restarted if we're interrupted.
if (!$socketActivated) {
write_file($startListFile, { append => 1 }, "$unit\n");
$unitsToStart{$unit} = 1;
recordUnit($startListFile, $unit);
}
push @unitsToStop, $unit;
$unitsToStop{$unit} = 1;
}
}
@ -268,14 +288,16 @@ foreach my $mountPoint (keys %$prevFss) {
my $unit = pathToUnitName($mountPoint) . ".mount";
if (!defined $new) {
# Filesystem entry disappeared, so unmount it.
push @unitsToStop, $unit;
$unitsToStop{$unit} = 1;
} elsif ($prev->{fsType} ne $new->{fsType} || $prev->{device} ne $new->{device}) {
# Filesystem type or device changed, so unmount and mount it.
write_file($startListFile, { append => 1 }, "$unit\n");
push @unitsToStop, $unit;
$unitsToStop{$unit} = 1;
$unitsToStart{$unit} = 1;
recordUnit($startListFile, $unit);
} elsif ($prev->{options} ne $new->{options}) {
# Mount options changes, so remount it.
write_file($reloadListFile, { append => 1 }, "$unit\n");
$unitsToReload{$unit} = 1;
recordUnit($reloadListFile, $unit);
}
}
@ -294,14 +316,36 @@ foreach my $device (keys %$prevSwaps) {
# FIXME: update swap options (i.e. its priority).
}
if (scalar @unitsToStop > 0) {
@unitsToStop = unique(@unitsToStop);
print STDERR "stopping the following units: ", join(", ", sort(@unitsToStop)), "\n";
system("systemctl", "stop", "--", @unitsToStop); # FIXME: ignore errors?
# Should we have systemd re-exec itself?
my $restartSystemd = abs_path("/proc/1/exe") ne abs_path("@systemd@/lib/systemd/systemd");
# Show dry-run actions.
if ($action eq "dry-activate") {
print STDERR "would stop the following units: ", join(", ", sort(keys %unitsToStop)), "\n"
if scalar(keys %unitsToStop) > 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(", ", sort(keys %unitsToStart)), "\n";
print STDERR "would reload the following units: ", join(", ", sort(keys %unitsToReload)), "\n"
if scalar(keys %unitsToReload) > 0;
exit 0;
}
print STDERR "NOT restarting the following units: ", join(", ", sort(@unitsToSkip)), "\n"
if scalar @unitsToSkip > 0;
syslog(LOG_NOTICE, "switching to system configuration $out");
if (scalar (keys %unitsToStop) > 0) {
print STDERR "stopping the following units: ", join(", ", sort(keys %unitsToStop)), "\n";
system("systemctl", "stop", "--", sort(keys %unitsToStop)); # FIXME: ignore errors?
}
print STDERR "NOT restarting the following changed units: ", join(", ", sort(keys %unitsToSkip)), "\n"
if scalar(keys %unitsToSkip) > 0;
# Activate the new configuration (i.e., update /etc, make accounts,
# and so on).
@ -310,7 +354,7 @@ print STDERR "activating the configuration...\n";
system("$out/activate", "$out") == 0 or $res = 2;
# Restart systemd if necessary.
if (abs_path("/proc/1/exe") ne abs_path("@systemd@/lib/systemd/systemd")) {
if ($restartSystemd) {
print STDERR "restarting systemd...\n";
system("@systemd@/bin/systemctl", "daemon-reexec") == 0 or $res = 2;
}
@ -327,10 +371,9 @@ system("@systemd@/bin/systemctl", "reload-or-restart", "dbus.service");
# Restart changed services (those that have to be restarted rather
# than stopped and started).
my @restart = unique(split('\n', read_file($restartListFile, err_mode => 'quiet') // ""));
if (scalar @restart > 0) {
print STDERR "restarting the following units: ", join(", ", sort(@restart)), "\n";
system("@systemd@/bin/systemctl", "restart", "--", @restart) == 0 or $res = 4;
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);
}
@ -340,17 +383,15 @@ if (scalar @restart > 0) {
# 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 @start = unique("default.target", "timers.target", "sockets.target", split('\n', read_file($startListFile, err_mode => 'quiet') // ""));
print STDERR "starting the following units: ", join(", ", sort(@start)), "\n";
system("@systemd@/bin/systemctl", "start", "--", @start) == 0 or $res = 4;
print STDERR "starting the following units: ", join(", ", sort(keys %unitsToStart)), "\n";
system("@systemd@/bin/systemctl", "start", "--", sort(keys %unitsToStart)) == 0 or $res = 4;
unlink($startListFile);
# Reload units that need it. This includes remounting changed mount
# units.
my @reload = unique(split '\n', read_file($reloadListFile, err_mode => 'quiet') // "");
if (scalar @reload > 0) {
print STDERR "reloading the following units: ", join(", ", sort(@reload)), "\n";
system("@systemd@/bin/systemctl", "reload", "--", @reload) == 0 or $res = 4;
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);
}