Automatically stop games on machine shutdown or reboot. (#291)

* Add script to shutdown all games

* Unit file that shuts down all active games.

Add this file to /etc/systemd/system to prevent minecraft games from being corruipted on shutdown/reboot.

* Fix systemd not waiting for the stop process

It seems that unless there is a timeout, systemd just shuts down anyway.
Sheesh!

* Forgot the actual mineos code!

init/mineos-games.service

@@ -0,0 +1,17 @@
+[Unit]
+Description=Stop MineOS-controlled minecraft games at shutdown
+After=network.target
+
+[Service]
+User=root
+WorkingDirectory=/usr/games/minecraft
+Type=oneshot
+Environment="SHELL=/bin/bash"
+ExecStart=/bin/true
+ExecStop=/usr/bin/node mineos_shutdown.js
+StandardOutput=syslog
+RemainAfterExit=yes
+TimeoutStopSec=120
+
+[Install]
+WantedBy=multi-user.target

mineos-games.service

@@ -0,0 +1,16 @@
+[Unit]
+Description=Stop MineOS-controlled minecraft games at shutdown
+After=network.target
+
+[Service]
+User=root
+WorkingDirectory=/usr/games/minecraft
+Type=oneshot
+Environment="SHELL=/bin/bash"
+ExecStart=/bin/true
+ExecStop=/usr/bin/node mineos_shutdown.js
+StandardOutput=syslog
+RemainAfterExit=yes
+
+[Install]
+WantedBy=multi-user.target

mineos_shutdown.js

@@ -0,0 +1,76 @@
+#!/usr/bin/env node
+
+var getopt = require('node-getopt');
+var mineos = require('./mineos');
+var fs = require('fs-extra');
+
+
+function read_ini(filepath) {
+    var ini = require('ini');
+    try {
+        var data = fs.readFileSync(filepath);
+        return ini.parse(data.toString());
+    } catch (e) {
+        return null;
+    }
+}
+
+console.log("Stopping running games");
+
+// List names of running servers
+var servers = mineos.server_list_up();
+
+// Read base directory configurations
+var mineos_config = read_ini('/etc/mineos.conf') || read_ini('/usr/local/etc/mineos.conf') || {};
+var base_directory = '/var/games/minecraft';
+
+if ('base_directory' in mineos_config) {
+    try {
+        if (mineos_config['base_directory'].length < 2)
+            throw new error('Invalid base_directory length.');
+
+        base_directory = mineos_config['base_directory'];
+        fs.ensureDirSync(base_directory);
+
+    } catch (e) {
+        console.error(e.message, 'Aborting shutdown.');
+        process.exit(2);
+    }
+
+    console.info('base_directory found in mineos.conf, using:', base_directory);
+} else {
+    console.error('base_directory not specified--missing mineos.conf?');
+    console.error('Aborting startup.');
+    process.exit(4);
+}
+
+// List of running servers
+var server_watches=[]
+
+function make_cb(server_watch)
+{
+    return function() {
+        console.log("    stopped server",server_watch.name);
+        server_watch.running = false;
+        for (w of server_watches) {
+            if (w.running){
+                console.log("  waiting for",w.name);
+            }
+        }                
+    };
+}
+
+for (server of servers) {
+
+    // obect to track state of server
+    var server_watch = {name:server, running:true};
+    server_watches.push(server_watch);    
+
+    var instance = new mineos.mc(server, base_directory);
+    console.log("Stopping", server);
+    cb_stopped = make_cb(server_watch);
+
+    instance.stop(cb_stopped);
+
+}
+console.log("Waiting for servers to stop");