add ago, fix bug

lib/common.js

@@ -106,6 +106,34 @@ function kvToObj(kvs, valid) {
     return o;
 }
 
+/**
+ * return how long ago something happened
+ *
+ * @param {Date} when - a date object in the past
+ * @param {Date} now (optional) - a date object to compare to
+ * @return {String} - printable string
+ */
+function longAgo(when, now) {
+    now = now || new Date();
+    var seconds = Math.round((now - when) / 1000);
+    var times = [
+        seconds / 60 / 60 / 24 / 365, // years
+        seconds / 60 / 60 / 24 / 30,  // months
+        seconds / 60 / 60 / 24,       // days
+        seconds / 60 / 60,            // hours
+        seconds / 60,                 // minutes
+        seconds                       // seconds
+    ];
+    var names = ['y', 'mon', 'd', 'h', 'min', 's'];
+
+    for (var i = 0; i < names.length; i++) {
+        var time = Math.floor(times[i]);
+        if (time > 0)
+            return util.format('%d%s', time, names[i]);
+    }
+    return '0s';
+}
+
 //---- exports
 
 module.exports = {
@@ -114,6 +142,7 @@ module.exports = {
     zeroPad: zeroPad,
     boolFromString: boolFromString,
     jsonStream: jsonStream,
-    kvToObj: kvToObj
+    kvToObj: kvToObj,
+    longAgo: longAgo
 };
 // vim: set softtabstop=4 shiftwidth=4:

lib/do_instances.js

@@ -32,7 +32,8 @@ var validFields = [
     'created',
     'updated',
     'package',
-    'image'
+    'image',
+    'ago'
 ];
 
 function do_instances(subcmd, opts, args, callback) {
@@ -60,6 +61,14 @@ function do_instances(subcmd, opts, args, callback) {
             callback(err);
             return;
         }
+
+        // add extra fields for nice output
+        var now = new Date();
+        machines.forEach(function (machine) {
+            var created = new Date(machine.created);
+            machine.ago = common.longAgo(created, now);
+        });
+
         if (opts.json) {
             console.log(common.jsonStream(machines));
         } else {
@@ -88,7 +97,7 @@ do_instances.options = [
     {
         names: ['o'],
         type: 'string',
-        default: 'id,name,state,type,image,memory,disk',
+        default: 'id,name,state,type,image,memory,disk,ago',
         help: 'Specify fields (columns) to output.',
         helpArg: 'field1,...'
     },
@@ -114,6 +123,6 @@ do_instances.help = (
     + '{{options}}'
 );
 
-do_packages.aliases = ['insts'];
+do_instances.aliases = ['insts'];
 
 module.exports = do_instances;