joyent/node-triton#26 triton command crashes with self-signed cert

Refactor do_instances to not call `callback` twice. Also don't assume
if a `res` on an error callback from CloudApi._request.

Fixes #26.

lib/cloudapi2.js

@@ -342,6 +342,7 @@ CloudApi.prototype.listKeys = function listKeys(opts, cb) {
  * <http://apidocs.joyent.com/cloudapi/#ListImages>
  *
  * @param {Object} options (optional)
+ *      XXX be more strict about accepted options
  *      XXX document this, see the api doc above :)
  * @param {Function} callback of the form `function (err, images, res)`
  */
@@ -553,9 +554,12 @@ function createListMachinesStream(options) {
         var endpoint = self._path(format('/%s/machines', self.user), options);
 
         self._request(endpoint, function (err, req, res, body) {
+            if (err) {
+                return donecb(err);
+            }
             var resourcecount = res.headers['x-resource-count'];
             var done = once || resourcecount < options.limit;
-            donecb(err, {done: done, results: body});
+            donecb(null, {done: done, results: body});
         });
     }
 };

lib/do_instances.js

@@ -10,12 +10,14 @@
  * `triton instances ...`
  */
 
-var f = require('util').format;
-
+var format = require('util').format;
 var tabula = require('tabula');
+var vasync = require('vasync');
 
 var common = require('./common');
 
+
+
 // to be passed as query string args to /my/machines
 var validFilters = [
     'name',
@@ -36,6 +38,7 @@ var columnsDefaultLong = 'id,name,img,package,state,primaryIp,created';
 var sortDefault = 'created';
 
 function do_instances(subcmd, opts, args, callback) {
+    var self = this;
     if (opts.help) {
         this.do_help('help', {}, [subcmd], callback);
         return;
@@ -59,55 +62,64 @@ function do_instances(subcmd, opts, args, callback) {
         return;
     }
 
-    var i = 0;
 
-    i++;
-    var images;
-    this.tritonapi.listImages({useCache: true}, function (err, _images) {
+    var imgs;
+    var insts;
+
+    vasync.parallel({funcs: [
+        function getTheImages(next) {
+            self.tritonapi.listImages({useCache: true}, function (err, _imgs) {
                 if (err) {
-            callback(err);
-            return;
+                    next(err);
+                } else {
+                    imgs = _imgs;
+                    next();
                 }
-        images = _images;
-        done();
             });
-
-    i++;
-    var machines;
-    this.tritonapi.cloudapi.listMachines(listOpts, function (err, _machines) {
+        },
+        function getTheMachines(next) {
+            self.tritonapi.cloudapi.listMachines(listOpts,
+                    function (err, _insts) {
                 if (err) {
-            callback(err);
-            return;
+                    next(err);
+                } else {
+                    insts = _insts;
+                    next();
                 }
-        machines = _machines;
-        done();
             });
-
-    function done() {
-        if (--i > 0)
-            return;
+        }
+    ]}, function (err, results) {
+        /*
+         * Error handling: vasync.parallel's `err` is always a MultiError. We
+         * want to prefer the `getTheMachines` err, e.g. if both get a
+         * self-signed cert error.
+         */
+        if (err) {
+            err = results.operations[1].err || err;
+            return callback(err);
+        }
 
         // map "uuid" => "image_name"
         var imgmap = {};
-        images.forEach(function (image) {
-            imgmap[image.id] = f('%s@%s', image.name, image.version);
+        imgs.forEach(function (img) {
+            imgmap[img.id] = format('%s@%s', img.name, img.version);
         });
 
         // Add extra fields for nice output.
         // XXX FWIW, the "extra fields" for images and packages are not added
         //     for `opts.json`. Thoughts? We should be consistent there. --TM
         var now = new Date();
-        machines.forEach(function (machine) {
-            var created = new Date(machine.created);
-            machine.ago = common.longAgo(created, now);
-            machine.img = imgmap[machine.image] || machine.image;
-            machine.shortid = machine.id.split('-', 1)[0];
+        insts.forEach(function (inst) {
+            var created = new Date(inst.created);
+            inst.ago = common.longAgo(created, now);
+            inst.img = imgmap[inst.image] || inst.image;
+            inst.shortid = inst.id.split('-', 1)[0];
         });
 
         if (opts.json) {
-            common.jsonStream(machines);
+            common.jsonStream(insts);
         } else {
-            tabula(machines, {
+            tabula(insts, {
                 skipHeader: opts.H,
                 columns: columns,
                 sort: sort,
@@ -115,7 +127,7 @@ function do_instances(subcmd, opts, args, callback) {
             });
         }
         callback();
-    }
+    });
 }
 
 do_instances.options = [