Ensure cli name ends with correct hostname

If longnames are in use, this also ensures that the domain (if known) is appended to the CLI node name

CLI node names will be based on RabbitMQ host names

Fixes #270

deps/rabbitmq_cli/lib/rabbitmq/cli/core/distribution.ex

@@ -13,9 +13,8 @@
 ## The Initial Developer of the Original Code is Pivotal Software, Inc.
 ## Copyright (c) 2016-2017 Pivotal Software, Inc.  All rights reserved.
 
-alias RabbitMQ.CLI.Core.Config
-
 defmodule RabbitMQ.CLI.Core.Distribution do
+  alias RabbitMQ.CLI.Core.{Config, Helpers}
 
   #
   # API
@@ -79,26 +78,32 @@ defmodule RabbitMQ.CLI.Core.Distribution do
   end
 
   defp generate_cli_node_name(node_name_type) do
-    base                 = "rabbitmqcli" <> to_string(:rabbit_misc.random(100))
+    rmq_hostname         = Helpers.get_rabbit_hostname()
+    base                 = "rabbitmqcli-#{:os.getpid()}-#{rmq_hostname}"
     inet_resolver_config = :inet.get_rc()
-
     case {node_name_type, Keyword.get(inet_resolver_config, :domain)} do
-      {:longnames, nil} ->
-        generate_dot_no_domain_name(base);
-      {:longnames, ""}  ->
-        generate_dot_no_domain_name(base);
+      {:longnames, domain}  ->
+        ensure_ends_with_domain(base, domain)
       _ ->
         base
     end |> String.to_atom
-
   end
 
-  defp generate_dot_no_domain_name(base) do
+  defp ensure_ends_with_domain(base, nil) do
+    "#{base}.localdomain"
+  end
+  defp ensure_ends_with_domain(base, "") do
+    "#{base}.localdomain"
+  end
+  defp ensure_ends_with_domain(base, domain) do
     # Distribution will fail to start if it's unable to
     # determine FQDN of a node (with at least one dot in
     # the name).
-    # The CLI always acts as a connection initiator, so it
-    # doesn't matter if the name will not resolve.
-    base <> "@" <> to_string(:inet_db.gethostname()) <> ".no-domain"
+    case String.ends_with?(base, to_string(domain)) do
+      true ->
+        base
+      _ ->
+        "#{base}.#{domain}"
+    end
   end
 end