nixpkgs/modules/system/upstart/upstart.nix
Eelco Dolstra d7342c78d4 * Support pre-stop scripts. These are needed to cleanly shutdown
daemons such as Apache or PostgreSQL.

svn path=/nixos/branches/upstart-0.6/; revision=18234
2009-11-06 22:45:19 +00:00

346 lines
8.7 KiB
Nix

{config, pkgs, ...}:
with pkgs.lib;
let
upstart = pkgs.upstart06;
# Path for Upstart jobs. Should be quite minimal.
upstartPath =
[ pkgs.coreutils
pkgs.findutils
pkgs.gnugrep
pkgs.gnused
upstart
];
# From a job description, generate an Upstart job file.
makeJob = job:
let
jobText =
''
# Upstart job `${job.name}'. This is a generated file. Do not edit.
description "${job.description}"
console output
${if isList job.startOn then
"start on ${concatStringsSep " or " job.startOn}"
else if job.startOn != "" then
"start on ${job.startOn}"
else ""
}
${optionalString (job.stopOn != "") "stop on ${job.stopOn}"}
env PATH=${makeSearchPath "bin" upstartPath}:${makeSearchPath "sbin" upstartPath}
${concatMapStrings (n: "env ${n}=${getAttr n job.environment}\n") (attrNames job.environment)}
${optionalString (job.preStart != "") ''
pre-start script
${job.preStart}
end script
''}
${if job.script != "" && job.exec != "" then
abort "Job ${job.name} has both a `script' and `exec' attribute."
else if job.script != "" then
''
script
${job.script}
end script
''
else if job.exec != "" then
''
exec ${job.exec}
''
else ""
}
${optionalString (job.postStart != "") ''
post-start script
${job.postStart}
end script
''}
${optionalString job.task "task"}
${optionalString job.respawn "respawn"}
${optionalString (job.preStop != "") ''
pre-stop script
${job.preStop}
end script
''}
${optionalString (job.postStop != "") ''
post-stop script
${job.postStop}
end script
''}
${optionalString (!job.task) (
if job.daemonType == "fork" then "expect fork" else
if job.daemonType == "daemon" then "expect daemon" else
if job.daemonType == "stop" then "expect stop" else
if job.daemonType == "none" then "" else
throw "invalid daemon type `${job.daemonType}'"
)}
${job.extraConfig}
'';
in
pkgs.runCommand ("upstart-" + job.name + ".conf")
{ inherit (job) buildHook; inherit jobText; }
''
eval "$buildHook"
echo "$jobText" > $out
'';
jobOptions = {
name = mkOption {
# !!! The type should ensure that this could be a filename.
type = types.string;
example = "sshd";
description = ''
Name of the Upstart job.
'';
};
buildHook = mkOption {
type = types.string;
default = "true";
description = ''
Command run while building the Upstart job. Can be used
to perform simple regression tests (e.g., the Apache
Upstart job uses it to check the syntax of the generated
<filename>httpd.conf</filename>.
'';
};
description = mkOption {
type = types.string;
default = "(no description given)";
description = ''
A short description of this job.
'';
};
startOn = mkOption {
# !!! Re-enable this once we're on Upstart >= 0.6.
#type = types.string;
default = "";
description = ''
The Upstart event that triggers this job to be started.
If empty, the job will not start automatically.
'';
};
stopOn = mkOption {
type = types.string;
default = "shutdown";
description = ''
The Upstart event that triggers this job to be stopped.
'';
};
preStart = mkOption {
type = types.string;
default = "";
description = ''
Shell commands executed before the job is started
(i.e. before the job's main process is started).
'';
};
postStart = mkOption {
type = types.string;
default = "";
description = ''
Shell commands executed after the job is started (i.e. after
the job's main process is started), but before the job is
considered running.
'';
};
preStop = mkOption {
type = types.string;
default = "";
description = ''
Shell commands executed before the job is stopped
(i.e. before Upstart kills the job's main process). This can
be used to cleanly shut down a daemon.
'';
};
postStop = mkOption {
type = types.string;
default = "";
description = ''
Shell commands executed after the job has stopped
(i.e. after the job's main process has terminated).
'';
};
exec = mkOption {
type = types.string;
default = "";
description = ''
Command to start the job's main process. If empty, the
job has no main process, but can still have pre/post-start
and pre/post-stop scripts, and is considered running
until it is stopped.
'';
};
script = mkOption {
type = types.string;
default = "";
description = ''
Shell commands executed as the job's main process. Can be
specified instead of the <varname>exec</varname> attribute.
'';
};
respawn = mkOption {
type = types.bool;
default = true;
description = ''
Whether to restart the job automatically if its process
ends unexpectedly.
'';
};
task = mkOption {
type = types.bool;
default = false;
description = ''
Whether this job is a task rather than a service. Tasks
are executed only once, while services are restarted when
they exit.
'';
};
environment = mkOption {
type = types.attrs;
default = {};
example = { PATH = "/foo/bar/bin"; LANG = "nl_NL.UTF-8"; };
description = ''
Environment variables passed to the job's processes.
'';
};
daemonType = mkOption {
type = types.string;
default = "none";
description = ''
Determines how Upstart detects when a daemon should be
considered running. The value <literal>none</literal> means
that the daemon is considered ready immediately. The value
<literal>fork</literal> means that the daemon will fork once.
The value <literal>daemon</literal> means that the daemon will
fork twice. The value <literal>stop</literal> means that the
daemon will raise the SIGSTOP signal to indicate readiness.
'';
};
extraConfig = mkOption {
type = types.string;
default = "";
example = "limit nofile 4096 4096";
description = ''
Additional Upstart stanzas not otherwise supported.
'';
};
};
upstartJob = {name, config, ...}: {
options = {
jobDrv = mkOption {
default = makeJob config;
type = types.uniq types.package;
description = ''
Derivation that builds the Upstart job file. The default
value is generated from other options.
'';
};
};
config = {
# The default name is the name extracted from the attribute path.
name = mkDefaultValue (
replaceChars ["<" ">" "*"] ["_" "_" "_name_"] name
);
};
};
in
{
###### interface
options = {
jobs = mkOption {
default = {};
description = ''
This option defines the system jobs started and managed by the
Upstart daemon.
'';
type = types.attrsOf types.optionSet;
options = [ jobOptions upstartJob ];
};
tests.upstartJobs = mkOption {
internal = true;
default = {};
description = ''
Make it easier to build individual Upstart jobs. (e.g.,
<command>nix-build /etc/nixos/nixos -A
tests.upstartJobs.xserver</command>).
'';
};
};
###### implementation
config = {
system.build.upstart = upstart;
environment.etc =
flip map (attrValues config.jobs) (job:
{ source = job.jobDrv;
target = "init/${job.name}.conf";
} );
# Upstart can listen on the system bus, allowing normal users to
# do status queries.
services.dbus.packages = [ upstart ];
# !!! fix this
/*
tests.upstartJobs = { recurseForDerivations = true; } //
builtins.listToAttrs (map (job: {
name = removePrefix "upstart-" job.name;
value = job;
}) jobs);
*/
};
}