Provide hint when user tries and fails to connect to localhost or 127.0.0.1.

Author: Wieger Steggerda

lib/cluster.js

@@ -26,6 +26,8 @@ var async = require('async');
 var AdminClient = require('./admin-client.js');
 var Partition = require('./partition.js');
 var Stats = require('./stats.js');
+var format = require('util').format;
+var startsWith = require('./util.js').startsWith;
 
 function Cluster(opts) {
     opts = opts || {
@@ -177,7 +179,16 @@ Cluster.prototype.fetchStats = function fetchStats(callback) {
 
     function onComplete(err, allStats) {
         if (allStats.length === 0) {
-            callback(new Error('Failed to connect to any ringpop members'));
+            var addr = self.coordAddr;
+            var msg = format('Failed to connect to ringpop listening on %s.', addr);
+
+            // Check if user tries to connect to localhost or 127.0.0.1.
+            if (typeof addr === 'string' &&
+                (startsWith(addr, 'localhost') || startsWith(addr, '127.0.0.1'))) {
+                msg += ' Ringpop ordinarily does not listen on the loopback interface. Try a different IP address.';
+            }
+
+            callback(new Error(msg));
             return;
         }
         self.lastDownloadTime = Date.now() - downloadTime;

lib/util.js

@@ -40,9 +40,14 @@ function safeParse(data) {
     }
 }
 
+function startsWith(str, str2) {
+    return str.substring(0, str2.length) === str2;
+}
+
 module.exports = {
     assertNoErr: assertNoError,
     assertNoError: assertNoError,
     assertTruthy: assertTruthy,
-    safeParse: safeParse
+    safeParse: safeParse,
+    startsWith: startsWith
 };

tests/partitions.t

@@ -14,6 +14,27 @@ With bootstrap file:
 
 Unable to connect to host:
 
+  $ ringpop-admin partitions 0.0.0.1:2999
+  Error while fetching node stats: { [TchannelSocketError: tchannel socket error (* from connect): connect *] (glob)
+    type: 'tchannel.socket',
+    message: 'tchannel socket error (* from connect): connect *', (glob)
+    hostPort: null,
+    direction: 'out',
+    remoteAddr: null,
+    name: 'TchannelSocketError',
+    socketRemoteAddr: '0.0.0.1:2999',
+    causeMessage: 'connect *', (glob)
+    origMessage: 'connect *', (glob)
+    code: '*', (glob)
+    errno: '*', (glob)
+    syscall: 'connect',
+    fullType: 'tchannel.socket~!~error.wrapped-io.connect.*' } (glob)
+  Error: Failed to connect to ringpop listening on 0.0.0.1:2999.
+  [1]
+
+
+Provide hint if the user tries and fails to connect to localhost or 127.0.0.1
+
   $  ringpop-admin partitions 127.0.0.1:2999
   Error while fetching node stats: { [TchannelSocketError: tchannel socket error (ECONNREFUSED from connect): connect ECONNREFUSED]
     type: 'tchannel.socket',
@@ -29,5 +50,23 @@ Unable to connect to host:
     errno: 'ECONNREFUSED',
     syscall: 'connect',
     fullType: 'tchannel.socket~!~error.wrapped-io.connect.ECONNREFUSED' }
-  Error: Failed to connect to any ringpop members
+  Error: Failed to connect to ringpop listening on 127.0.0.1:2999. Ringpop ordinarily does not listen on the loopback interface. Try a different IP address.
+  [1]
+
+  $  ringpop-admin partitions localhost:2999
+  Error while fetching node stats: { [TchannelSocketError: tchannel socket error (ECONNREFUSED from connect): connect ECONNREFUSED]
+    type: 'tchannel.socket',
+    message: 'tchannel socket error (ECONNREFUSED from connect): connect ECONNREFUSED',
+    hostPort: null,
+    direction: 'out',
+    remoteAddr: null,
+    name: 'TchannelSocketError',
+    socketRemoteAddr: 'localhost:2999',
+    causeMessage: 'connect ECONNREFUSED',
+    origMessage: 'connect ECONNREFUSED',
+    code: 'ECONNREFUSED',
+    errno: 'ECONNREFUSED',
+    syscall: 'connect',
+    fullType: 'tchannel.socket~!~error.wrapped-io.connect.ECONNREFUSED' }
+  Error: Failed to connect to ringpop listening on localhost:2999. Ringpop ordinarily does not listen on the loopback interface. Try a different IP address.
   [1]