pyrox.dev
1{ config, lib, pkgs, ... }:
2
3with lib;
4
5let
6 cfg = config.services.apcupsd;
7
8 configFile = pkgs.writeText "apcupsd.conf" ''
9 ## apcupsd.conf v1.1 ##
10 # apcupsd complains if the first line is not like above.
11 ${cfg.configText}
12 SCRIPTDIR ${toString scriptDir}
13 '';
14
15 # List of events from "man apccontrol"
16 eventList = [
17 "annoyme"
18 "battattach"
19 "battdetach"
20 "changeme"
21 "commfailure"
22 "commok"
23 "doreboot"
24 "doshutdown"
25 "emergency"
26 "failing"
27 "killpower"
28 "loadlimit"
29 "mainsback"
30 "onbattery"
31 "offbattery"
32 "powerout"
33 "remotedown"
34 "runlimit"
35 "timeout"
36 "startselftest"
37 "endselftest"
38 ];
39
40 shellCmdsForEventScript = eventname: commands: ''
41 echo "#!${pkgs.runtimeShell}" > "$out/${eventname}"
42 echo '${commands}' >> "$out/${eventname}"
43 chmod a+x "$out/${eventname}"
44 '';
45
46 eventToShellCmds = event: if builtins.hasAttr event cfg.hooks then (shellCmdsForEventScript event (builtins.getAttr event cfg.hooks)) else "";
47
48 scriptDir = pkgs.runCommand "apcupsd-scriptdir" { preferLocalBuild = true; } (''
49 mkdir "$out"
50 # Copy SCRIPTDIR from apcupsd package
51 cp -r ${pkgs.apcupsd}/etc/apcupsd/* "$out"/
52 # Make the files writeable (nix will unset the write bits afterwards)
53 chmod u+w "$out"/*
54 # Remove the sample event notification scripts, because they don't work
55 # anyways (they try to send mail to "root" with the "mail" command)
56 (cd "$out" && rm changeme commok commfailure onbattery offbattery)
57 # Remove the sample apcupsd.conf file (we're generating our own)
58 rm "$out/apcupsd.conf"
59 # Set the SCRIPTDIR= line in apccontrol to the dir we're creating now
60 sed -i -e "s|^SCRIPTDIR=.*|SCRIPTDIR=$out|" "$out/apccontrol"
61 '' + concatStringsSep "\n" (map eventToShellCmds eventList)
62
63 );
64
65 # Ensure the CLI uses our generated configFile
66 wrappedBinaries = pkgs.runCommandLocal "apcupsd-wrapped-binaries"
67 { nativeBuildInputs = [ pkgs.makeWrapper ]; }
68 ''
69 for p in "${lib.getBin pkgs.apcupsd}/bin/"*; do
70 bname=$(basename "$p")
71 makeWrapper "$p" "$out/bin/$bname" --add-flags "-f ${configFile}"
72 done
73 '';
74
75 apcupsdWrapped = pkgs.symlinkJoin {
76 name = "apcupsd-wrapped";
77 # Put wrappers first so they "win"
78 paths = [ wrappedBinaries pkgs.apcupsd ];
79 };
80in
81
82{
83
84 ###### interface
85
86 options = {
87
88 services.apcupsd = {
89
90 enable = mkOption {
91 default = false;
92 type = types.bool;
93 description = ''
94 Whether to enable the APC UPS daemon. apcupsd monitors your UPS and
95 permits orderly shutdown of your computer in the event of a power
96 failure. User manual: http://www.apcupsd.com/manual/manual.html.
97 Note that apcupsd runs as root (to allow shutdown of computer).
98 You can check the status of your UPS with the "apcaccess" command.
99 '';
100 };
101
102 configText = mkOption {
103 default = ''
104 UPSTYPE usb
105 NISIP 127.0.0.1
106 BATTERYLEVEL 50
107 MINUTES 5
108 '';
109 type = types.lines;
110 description = ''
111 Contents of the runtime configuration file, apcupsd.conf. The default
112 settings makes apcupsd autodetect USB UPSes, limit network access to
113 localhost and shutdown the system when the battery level is below 50
114 percent, or when the UPS has calculated that it has 5 minutes or less
115 of remaining power-on time. See man apcupsd.conf for details.
116 '';
117 };
118
119 hooks = mkOption {
120 default = {};
121 example = {
122 doshutdown = "# shell commands to notify that the computer is shutting down";
123 };
124 type = types.attrsOf types.lines;
125 description = ''
126 Each attribute in this option names an apcupsd event and the string
127 value it contains will be executed in a shell, in response to that
128 event (prior to the default action). See "man apccontrol" for the
129 list of events and what they represent.
130
131 A hook script can stop apccontrol from doing its default action by
132 exiting with value 99. Do not do this unless you know what you're
133 doing.
134 '';
135 };
136
137 };
138
139 };
140
141
142 ###### implementation
143
144 config = mkIf cfg.enable {
145
146 assertions = [ {
147 assertion = let hooknames = builtins.attrNames cfg.hooks; in all (x: elem x eventList) hooknames;
148 message = ''
149 One (or more) attribute names in services.apcupsd.hooks are invalid.
150 Current attribute names: ${toString (builtins.attrNames cfg.hooks)}
151 Valid attribute names : ${toString eventList}
152 '';
153 } ];
154
155 # Give users access to the "apcaccess" tool
156 environment.systemPackages = [ apcupsdWrapped ];
157
158 # NOTE 1: apcupsd runs as root because it needs permission to run
159 # "shutdown"
160 #
161 # NOTE 2: When apcupsd calls "wall", it prints an error because stdout is
162 # not connected to a tty (it is connected to the journal):
163 # wall: cannot get tty name: Inappropriate ioctl for device
164 # The message still gets through.
165 systemd.services.apcupsd = {
166 description = "APC UPS Daemon";
167 wantedBy = [ "multi-user.target" ];
168 preStart = "mkdir -p /run/apcupsd/";
169 serviceConfig = {
170 ExecStart = "${pkgs.apcupsd}/bin/apcupsd -b -f ${configFile} -d1";
171 # TODO: When apcupsd has initiated a shutdown, systemd always ends up
172 # waiting for it to stop ("A stop job is running for UPS daemon"). This
173 # is weird, because in the journal one can clearly see that apcupsd has
174 # received the SIGTERM signal and has already quit (or so it seems).
175 # This reduces the wait time from 90 seconds (default) to just 5. Then
176 # systemd kills it with SIGKILL.
177 TimeoutStopSec = 5;
178 };
179 unitConfig.Documentation = "man:apcupsd(8)";
180 };
181
182 # A special service to tell the UPS to power down/hibernate just before the
183 # computer shuts down. (The UPS has a built in delay before it actually
184 # shuts off power.) Copied from here:
185 # http://forums.opensuse.org/english/get-technical-help-here/applications/479499-apcupsd-systemd-killpower-issues.html
186 systemd.services.apcupsd-killpower = {
187 description = "APC UPS Kill Power";
188 after = [ "shutdown.target" ]; # append umount.target?
189 before = [ "final.target" ];
190 wantedBy = [ "shutdown.target" ];
191 unitConfig = {
192 ConditionPathExists = "/run/apcupsd/powerfail";
193 DefaultDependencies = "no";
194 };
195 serviceConfig = {
196 Type = "oneshot";
197 ExecStart = "${pkgs.apcupsd}/bin/apcupsd --killpower -f ${configFile}";
198 TimeoutSec = "infinity";
199 StandardOutput = "tty";
200 RemainAfterExit = "yes";
201 };
202 };
203
204 };
205
206}