sysinfo: Add static and network intf providers

src/sysinfo/network-interface.js

@@ -0,0 +1,25 @@
+'use strict';
+
+exports = module.exports = {
+    getServerIp: getServerIp
+};
+
+var assert = require('assert'),
+    BoxError = require('../boxerror.js'),
+    debug = require('box:sysinfo/network-interface'),
+    os = require('os');
+
+function getServerIp(config, callback) {
+    assert.strictEqual(typeof config, 'object');
+    assert.strictEqual(typeof callback, 'function');
+
+    const ifaces = os.networkInterfaces();
+    const iface = ifaces[config.ifname]; // array of addresses
+    if (!iface) return callback(new BoxError(BoxError.NETWORK_ERROR, `No interface named ${config.ifname}`));
+
+    const addresses = iface.filter(i => i.family === 'IPv4').map(i => i.address);
+    if (addresses.length === 0) return callback(new BoxError(BoxError.NETWORK_ERROR, `${config.ifname} does not have any IPv4 address`));
+    if (addresses.length > 1) debug(`${config.ifname} has multiple ipv4 - ${JSON.stringify(addresses)}. choosing the first one.`);
+
+    return callback(null, addresses[0]);
+}