sysinfo: async'ify

in the process, provision, dyndns, mail, dns also got further asyncified

src/sysinfo.js

@@ -9,10 +9,7 @@ exports = module.exports = {
 
 const assert = require('assert'),
     fs = require('fs'),
-    settings = require('./settings.js'),
-    util = require('util');
-
-const getSysinfoConfig = util.callbackify(settings.getSysinfoConfig);
+    settings = require('./settings.js');
 
 function api(provider) {
     assert.strictEqual(typeof provider, 'string');
@@ -24,14 +21,10 @@ function api(provider) {
     }
 }
 
-function getServerIp(callback) {
-    assert.strictEqual(typeof callback, 'function');
+async function getServerIp() {
+    const config = await settings.getSysinfoConfig();
 
-    getSysinfoConfig(function (error, config) {
-        if (error) return callback(error);
-
-        api(config.provider).getServerIp(config, callback);
-    });
+    return await api(config.provider).getServerIp(config);
 }
 
 function hasIPv6() {
@@ -40,9 +33,8 @@ function hasIPv6() {
     return fs.existsSync(IPV6_PROC_FILE) && fs.readFileSync(IPV6_PROC_FILE, 'utf8').trim().length !== 0;
 }
 
-function testConfig(config, callback) {
+async function testConfig(config) {
     assert.strictEqual(typeof config, 'object');
-    assert.strictEqual(typeof callback, 'function');
 
-    api(config.provider).testConfig(config, callback);
+    return await api(config.provider).testConfig(config);
 }