implement failsafe connections. fix #92

README.md

@@ -225,6 +225,26 @@ plan.target('dynamic-hosts', function(done) {
 });
 ```
 
+Usually flightplan will abort when a host is not reachable or authentication
+fails. This can be prevented by setting a property `failsafe` to `true` on
+any of the host configurations:
+
+```bash
+plan.target('production', [
+  {
+    host: 'www1.example.com',
+    username: 'pstadler',
+    agent: process.env.SSH_AUTH_SOCK
+  },
+  {
+    host: 'www2.example.com',
+    username: 'pstadler',
+    agent: process.env.SSH_AUTH_SOCK,
+    failsafe: true // continue flightplan even if connection to www2 fails
+  }
+]);
+```
+
 You can override the `username` value of hosts by calling `fly` with
 the `-u|--username` option:
 
@@ -534,7 +554,7 @@ if(plan.runtime.target === 'production') {
 }
 ```
 
-### transport.waitFor(fn(done)) → mixed
+### transport.waitFor(fn(done)) → {} mixed
 
 Execute a function and return after the callback `done` is called.
 This is used for running asynchronous functions in a synchronous way.

lib/flight/remote.js

@@ -3,16 +3,27 @@ var Fiber = require('fibers')
   , extend = require('util-extend')
   , SSH = require('../transport/ssh')
   , logger = require('../logger')()
-  , prettyTime = require('pretty-hrtime');
+  , prettyTime = require('pretty-hrtime')
+  , errors = require('../errors');
 
 var _connections = [];
 
 exports.run = function(fn, context) {
   var connect = function(context) {
     var future = new Future();
     new Fiber(function() {
-      logger.info('Connecting to "' + context.remote.host + '"');
-      _connections.push(new SSH(context));
+      logger.info("Connecting to '" + context.remote.host + "'");
+      try {
+        var connection = new SSH(context);
+        _connections.push(connection);
+      } catch(e) {
+        if(!context.remote.failsafe) {
+          throw new errors.ConnectionFailedError("Error connecting to '" +
+                                context.remote.host + "': " + e.message);
+        }
+        logger.warn("Safely failed connecting to '" + context.remote.host +
+                                          "': " + e.message);
+      }
       return future.return();
     }).run();
     return future;

lib/index.js

@@ -182,6 +182,27 @@ function Flightplan() {
  * });
  * ```
  *
+ * Usually flightplan will abort when a host is not reachable or authentication
+ * fails. This can be prevented by setting a property `failsafe` to `true` on
+ * any of the host configurations:
+ *
+ * ```bash
+ * plan.target('production', [
+ *   {
+ *     host: 'www1.example.com',
+ *     username: 'pstadler',
+ *     agent: process.env.SSH_AUTH_SOCK
+ *   },
+ *   {
+ *     host: 'www2.example.com',
+ *     username: 'pstadler',
+ *     agent: process.env.SSH_AUTH_SOCK,
+ *     failsafe: true // continue flightplan even if connection to www2 fails
+ *   }
+ * ]);
+ * ```
+ *
+ *
  * You can override the `username` value of hosts by calling `fly` with
  * the `-u|--username` option:
  *

lib/transport/ssh.js

@@ -1,7 +1,7 @@
 var util = require('util')
   , extend = require('util-extend')
   , Fiber = require('fibers')
-  , Connection = require('ssh2')
+  , Connection = require('ssh2').Client
   , byline = require('byline')
   , Transport = require('./index')
   , errors = require('../errors')
@@ -48,9 +48,9 @@ function SSH(context) {
   });
 
   this._connection.on('error', function(err) {
-    throw new errors.ConnectionFailedError('Error connecting to ' +
-                                  self._context.remote.host + ': ' + err);
+    return fiber.throwInto(err);
   });
+
   this._connection.connect(config);
 
   return Fiber.yield();

package.json

@@ -1,7 +1,7 @@
 {
   "name": "flightplan",
   "description": "Library for streamlining application deployment or systems administration tasks",
-  "version": "0.6.3",
+  "version": "0.6.4",
   "author": "Patrick Stadler <patrick.stadler@gmail.com>",
   "keywords": [
     "deploy",