Revert "systemd: use sd-switch"

This reverts commit 9c0fe3957b.
This commit is contained in:
Robert Helgesson 2020-08-04 19:38:14 +02:00
parent 9c0fe3957b
commit 223e3c38a1
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5 changed files with 344 additions and 39 deletions

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@ -6,13 +6,10 @@ section is therefore not final.
[[sec-release-20.09-highlights]]
=== Highlights
:sd-switch-url: https://gitlab.com/rycee/sd-switch
This release has the following notable changes:
* The systemd activation is now handled by {sd-switch-url}[sd-switch], a program that stops, starts, reloads, etc. systemd units as necessary to match the new Home Manager configuration.
+
Since sd-switch is relatively lightweight it is always used and the option `systemd.user.startServices` is therefore considered obsolete and can be removed from your configuration.
* Nothing has happened.
[[sec-release-20.09-state-version-changes]]
=== State Version Changes

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@ -1619,21 +1619,6 @@ in
A new module is available: 'services.dropbox'.
'';
}
{
time = "2020-08-03T22:34:42+00:00";
condition = hostPlatform.isLinux && (with config.systemd.user;
services != {} || sockets != {} || targets != {} || timers != {});
message = ''
The systemd activation is now handled by 'sd-switch', a program that
stops, starts, reloads, etc. systemd units as necessary to match the
new Home Manager configuration.
Since sd-switch is relatively lightweight it is always used and the
option 'systemd.user.startServices' is therefore considered obsolete
and can be removed from your configuration.
'';
}
];
};
}

216
modules/systemd-activate.rb Normal file
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@ -0,0 +1,216 @@
require 'set'
require 'open3'
@dry_run = ENV['DRY_RUN']
@verbose = ENV['VERBOSE']
UnitsDir = 'home-files/.config/systemd/user'
# 1. Stop all services from the old generation that are not present in the new generation.
# 2. Ensure all services from the new generation that are wanted by active targets are running:
# - Start services that are not already running.
# - Restart services whose unit config files have changed between generations.
# 3. If any services were (re)started, wait 'start_timeout_ms' and report services
# that failed to start. This helps debugging quickly failing services.
#
# Whenever service failures are detected, show the output of
# 'systemd --user status' for the affected services.
#
def setup_services(old_gen_path, new_gen_path, start_timeout_ms_string)
start_timeout_ms = start_timeout_ms_string.to_i
old_units_path = File.join(old_gen_path, UnitsDir) unless old_gen_path.empty?
new_units_path = File.join(new_gen_path, UnitsDir)
old_services = get_services(old_units_path)
new_services = get_services(new_units_path)
exit if old_services.empty? && new_services.empty?
all_services = get_active_targets_units(new_units_path)
maybe_changed = all_services & old_services
changed_services = get_changed_services(old_units_path, new_units_path, maybe_changed)
unchanged_oneshots = get_oneshot_services(maybe_changed - changed_services)
# These services should be running when this script is finished
services_to_run = all_services - unchanged_oneshots
# Only stop active services, otherwise we might get a 'service not loaded' error
# for inactive services that were removed in the current generation.
to_stop = get_active_units(old_services - new_services)
to_restart = changed_services
to_start = get_inactive_units(services_to_run - to_restart)
raise "daemon-reload failed" unless run_cmd('systemctl', '--user', 'daemon-reload')
# Exclude units that shouldn't be (re)started or stopped
no_manual_start, no_manual_stop, no_restart = get_restricted_units(to_stop + to_restart + to_start)
notify_skipped_units(to_restart & no_restart)
to_stop -= no_manual_stop
to_restart -= no_manual_stop + no_manual_start + no_restart
to_start -= no_manual_start
if to_stop.empty? && to_start.empty? && to_restart.empty?
print_service_msg("All services are already running", services_to_run)
else
puts "Setting up services" if @verbose
systemctl_action('stop', to_stop)
systemctl_action('start', to_start)
systemctl_action('restart', to_restart)
started_services = to_start + to_restart
if start_timeout_ms > 0 && !started_services.empty? && !@dry_run
failed = wait_and_get_failed_services(started_services, start_timeout_ms)
if failed.empty?
print_service_msg("All services are running", services_to_run)
else
puts
puts "Error. These services failed to start:", failed
show_failed_services_status(failed)
exit 1
end
end
end
end
def get_services(dir)
services = get_service_files(dir) if dir && Dir.exists?(dir)
Set.new(services)
end
def get_service_files(dir)
Dir.chdir(dir) { Dir['*[^@].{service,socket,timer}'] }
end
def get_changed_services(dir_a, dir_b, services)
services.select do |service|
a = File.join(dir_a, service)
b = File.join(dir_b, service)
(File.size(a) != File.size(b)) || (File.read(a) != File.read(b))
end
end
TargetDirRegexp = /^(.*\.target)\.wants$/
# @return all units wanted by active targets
def get_active_targets_units(units_dir)
return Set.new unless Dir.exists?(units_dir)
targets = Dir.entries(units_dir).map { |entry| entry[TargetDirRegexp, 1] }.compact
active_targets = get_active_units(targets)
active_units = active_targets.map do |target|
get_service_files(File.join(units_dir, "#{target}.wants"))
end.flatten
Set.new(active_units)
end
# @return true on success
def run_cmd(*cmd)
print_cmd cmd
@dry_run || system(*cmd)
end
def systemctl_action(cmd, services)
return if services.empty?
verb = (cmd == 'stop') ? 'Stopping' : "#{cmd.capitalize}ing"
puts "#{verb}: #{services.join(' ')}"
cmd = ['systemctl', '--user', cmd, *services]
if @dry_run
puts cmd.join(' ')
return
end
output, status = Open3.capture2e(*cmd)
print output
# Show status for failed services
unless status.success?
# Due to a bug in systemd, the '--user' argument is not always provided
output.scan(/systemctl (?:--user )?(status .*?)['"]/).flatten.each do |status_cmd|
puts
run_cmd("systemctl --user #{status_cmd}")
end
exit 1
end
end
def systemctl(*cmd)
output, _ = Open3.capture2('systemctl', '--user', *cmd)
output
end
def print_cmd(cmd)
puts [*cmd].join(' ') if @verbose || @dry_run
end
def get_active_units(units)
filter_units(units) { |state| state == 'active' }
end
def get_inactive_units(units)
filter_units(units) { |state| state != 'active' }
end
def get_failed_units(units)
filter_units(units) { |state| state == 'failed' }
end
def filter_units(units)
return [] if units.empty?
states = systemctl('is-active', *units).split
units.select.with_index { |_, i| yield states[i] }
end
def get_oneshot_services(units)
return [] if units.empty?
types = systemctl('show', '-p', 'Type', *units).split
units.select.with_index do |_, i|
types[i] == 'Type=oneshot'
end
end
def get_restricted_units(units)
infos = systemctl('show', '-p', 'RefuseManualStart', '-p', 'RefuseManualStop', *units)
.split("\n\n")
no_manual_start = []
no_manual_stop = []
infos.zip(units).each do |info, unit|
no_start, no_stop = info.split("\n")
no_manual_start << unit if no_start.end_with?('yes')
no_manual_stop << unit if no_stop.end_with?('yes')
end
# Get units that should not be restarted even if a change has been detected.
no_restart_regexp = /^\s*X-RestartIfChanged\s*=\s*false\b/
no_restart = units.select { |unit| systemctl('cat', unit) =~ no_restart_regexp }
[no_manual_start, no_manual_stop, no_restart]
end
def wait_and_get_failed_services(services, start_timeout_ms)
puts "Waiting #{start_timeout_ms} ms for services to fail"
# Force the previous message to always be visible before sleeping
STDOUT.flush
sleep(start_timeout_ms / 1000.0)
get_failed_units(services)
end
def show_failed_services_status(services)
puts
services.each do |service|
run_cmd('systemctl', '--user', 'status', service)
puts
end
end
def print_service_msg(msg, services)
return if services.empty?
if @verbose
puts "#{msg}:", services.to_a
else
puts msg
end
end
def notify_skipped_units(no_restart)
puts "Not restarting: #{no_restart.join(' ')}" unless no_restart.empty?
end
setup_services(*ARGV)

114
modules/systemd-activate.sh Normal file
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@ -0,0 +1,114 @@
#!/usr/bin/env bash
function isStartable() {
local service="$1"
[[ $(systemctl --user show -p RefuseManualStart "$service") == *=no ]]
}
function isStoppable() {
if [[ -v oldGenPath ]] ; then
local service="$1"
[[ $(systemctl --user show -p RefuseManualStop "$service") == *=no ]]
fi
}
function systemdPostReload() {
local workDir
workDir="$(mktemp -d)"
if [[ -v oldGenPath ]] ; then
local oldUserServicePath="$oldGenPath/home-files/.config/systemd/user"
fi
local newUserServicePath="$newGenPath/home-files/.config/systemd/user"
local oldServiceFiles="$workDir/old-files"
local newServiceFiles="$workDir/new-files"
local servicesDiffFile="$workDir/diff-files"
if [[ ! (-v oldUserServicePath && -d "$oldUserServicePath") \
&& ! -d "$newUserServicePath" ]]; then
return
fi
if [[ ! (-v oldUserServicePath && -d "$oldUserServicePath") ]]; then
touch "$oldServiceFiles"
else
find "$oldUserServicePath" \
-maxdepth 1 -name '*.service' -exec basename '{}' ';' \
| sort \
> "$oldServiceFiles"
fi
if [[ ! -d "$newUserServicePath" ]]; then
touch "$newServiceFiles"
else
find "$newUserServicePath" \
-maxdepth 1 -name '*.service' -exec basename '{}' ';' \
| sort \
> "$newServiceFiles"
fi
diff \
--new-line-format='+%L' \
--old-line-format='-%L' \
--unchanged-line-format=' %L' \
"$oldServiceFiles" "$newServiceFiles" \
> "$servicesDiffFile" || true
local -a maybeRestart=( $(grep '^ ' "$servicesDiffFile" | cut -c2-) )
local -a maybeStop=( $(grep '^-' "$servicesDiffFile" | cut -c2-) )
local -a maybeStart=( $(grep '^+' "$servicesDiffFile" | cut -c2-) )
local -a toRestart=( )
local -a toStop=( )
local -a toStart=( )
for f in "${maybeRestart[@]}" ; do
if isStoppable "$f" \
&& isStartable "$f" \
&& systemctl --quiet --user is-active "$f" \
&& ! cmp --quiet \
"$oldUserServicePath/$f" \
"$newUserServicePath/$f" ; then
toRestart+=("$f")
fi
done
for f in "${maybeStop[@]}" ; do
if isStoppable "$f" ; then
toStop+=("$f")
fi
done
for f in "${maybeStart[@]}" ; do
if isStartable "$f" ; then
toStart+=("$f")
fi
done
rm -r "$workDir"
local sugg=""
if [[ -n "${toRestart[@]}" ]] ; then
sugg="${sugg}systemctl --user restart ${toRestart[@]}\n"
fi
if [[ -n "${toStop[@]}" ]] ; then
sugg="${sugg}systemctl --user stop ${toStop[@]}\n"
fi
if [[ -n "${toStart[@]}" ]] ; then
sugg="${sugg}systemctl --user start ${toStart[@]}\n"
fi
if [[ -n "$sugg" ]] ; then
echo "Suggested commands:"
echo -n -e "$sugg"
fi
}
oldGenPath="$1"
newGenPath="$2"
$DRY_RUN_CMD systemctl --user daemon-reload
systemdPostReload

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@ -54,6 +54,8 @@ let
buildServices = style: serviceCfgs:
concatLists (mapAttrsToList (buildService style) serviceCfgs);
servicesStartTimeoutMs = builtins.toString cfg.servicesStartTimeoutMs;
unitType = unitKind: with types;
let
primitive = either bool (either int str);
@ -150,11 +152,9 @@ in
example = unitExample "Path";
};
# Keep for a while for backwards compatibility.
startServices = mkOption {
default = false;
type = types.bool;
visible = false;
description = ''
Start all services that are wanted by active targets.
Additionally, stop obsolete services from the previous
@ -164,10 +164,10 @@ in
servicesStartTimeoutMs = mkOption {
default = 0;
type = types.ints.unsigned;
type = types.int;
description = ''
How long to wait for started services to fail until their start is
considered successful. The value 0 indicates no timeout.
How long to wait for started services to fail until their
start is considered successful.
'';
};
@ -203,10 +203,6 @@ in
"Must use Linux for modules that require systemd: " + names;
}
];
warnings = mkIf cfg.startServices [
"The option 'systemd.user.startServices' is obsolete and can be removed."
];
}
# If we run under a Linux system we assume that systemd is
@ -234,17 +230,13 @@ in
# set it ourselves in that case.
home.activation.reloadSystemD = hm.dag.entryAfter ["linkGeneration"] (
let
timeoutArg =
if cfg.servicesStartTimeoutMs != 0 then
"--timeout " + toString cfg.servicesStartTimeoutMs
else
"";
autoReloadCmd = ''
${pkgs.ruby}/bin/ruby ${./systemd-activate.rb} \
"''${oldGenPath=}" "$newGenPath" "${servicesStartTimeoutMs}"
'';
sdSwitchCmd = ''
${pkgs.sd-switch}/bin/sd-switch \
''${DRY_RUN:+--dry-run} $VERBOSE_ARG ${timeoutArg} \
''${oldGenPath:+--old-units $oldGenPath/home-files/.config/systemd/user} \
--new-units $newGenPath/home-files/.config/systemd/user
legacyReloadCmd = ''
bash ${./systemd-activate.sh} "''${oldGenPath=}" "$newGenPath"
'';
ensureRuntimeDir = "XDG_RUNTIME_DIR=\${XDG_RUNTIME_DIR:-/run/user/$(id -u)}";
@ -262,7 +254,8 @@ in
fi
${ensureRuntimeDir} \
${sdSwitchCmd}
PATH=${dirOf cfg.systemctlPath}:$PATH \
${if cfg.startServices then autoReloadCmd else legacyReloadCmd}
else
echo "User systemd daemon not running. Skipping reload."
fi