Add eth0 sysinfo backend

src/sysinfo.js

@@ -10,6 +10,7 @@ var assert = require('assert'),
     caas = require('./sysinfo/caas.js'),
     config = require('./config.js'),
     ec2 = require('./sysinfo/ec2.js'),
+    eth0 = require('./sysinfo/eth0.js'),
     util = require('util');
 
 var gCachedIp = null;
@@ -43,6 +44,7 @@ function getApi(callback) {
         case 'caas': return callback(null, caas);
         case 'digitalocean': return callback(null, caas);
         case 'ec2': return callback(null, ec2);
+        case 'eth0': return callback(null, eth0);
         default: return callback(new Error('Unkown provider ' + config.provider()));
     }
 }