From 34f853950685e4e7ab38f30fc3f17a6beac13349 Mon Sep 17 00:00:00 2001
From: Magnus Henoch
Date: Wed, 20 Apr 2016 14:40:39 +0100
Subject: Add -start_epmd command line option
Add a command line option that lets you disable automatic starting of
epmd when starting a distributed node.
This differs from the undocumented setting -no_epmd, in that it does
not affect the starting of an erl_epmd process within
erl_distribution: the newly started node will expect an epmd instance
to have been started previously.
---
erts/doc/src/erl.xml | 18 +++++++++++++++++-
erts/etc/common/erlexec.c | 21 ++++++++++++++++++++-
2 files changed, 37 insertions(+), 2 deletions(-)
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index 1bbde7f1e0..e63928ddb0 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -338,7 +338,8 @@
net_kernel(3).
It is also ensured that runs on the current host
before Erlang is started. See
- epmd(1).
+ -
Scans, parses and evaluates an arbitrary expression
diff --git a/lib/kernel/src/inet_tcp_dist.erl b/lib/kernel/src/inet_tcp_dist.erl
index 64b28bb49b..f91d7ef7c3 100644
--- a/lib/kernel/src/inet_tcp_dist.erl
+++ b/lib/kernel/src/inet_tcp_dist.erl
@@ -73,7 +73,8 @@ gen_listen(Driver, Name) ->
{ok, Socket} ->
TcpAddress = get_tcp_address(Driver, Socket),
{_,Port} = TcpAddress#net_address.address,
- case erl_epmd:register_node(Name, Port) of
+ ErlEpmd = net_kernel:epmd_module(),
+ case ErlEpmd:register_node(Name, Port) of
{ok, Creation} ->
{ok, {Socket, TcpAddress, Creation}};
Error ->
@@ -280,7 +281,8 @@ do_setup(Driver, Kernel, Node, Type, MyNode, LongOrShortNames, SetupTime) ->
case inet:getaddr(Address, AddressFamily) of
{ok, Ip} ->
Timer = dist_util:start_timer(SetupTime),
- case erl_epmd:port_please(Name, Ip) of
+ ErlEpmd = net_kernel:epmd_module(),
+ case ErlEpmd:port_please(Name, Ip) of
{port, TcpPort, Version} ->
?trace("port_please(~p) -> version ~p~n",
[Node,Version]),
diff --git a/lib/kernel/src/net_adm.erl b/lib/kernel/src/net_adm.erl
index a38356c224..8ec275b88b 100644
--- a/lib/kernel/src/net_adm.erl
+++ b/lib/kernel/src/net_adm.erl
@@ -96,7 +96,8 @@ names() ->
Reason :: address | file:posix().
names(Hostname) ->
- erl_epmd:names(Hostname).
+ ErlEpmd = net_kernel:epmd_module(),
+ ErlEpmd:names(Hostname).
-spec dns_hostname(Host) -> {ok, Name} | {error, Host} when
Host :: atom() | string(),
diff --git a/lib/ssl/src/inet_tls_dist.erl b/lib/ssl/src/inet_tls_dist.erl
index 3481e89af0..0da4b3587f 100644
--- a/lib/ssl/src/inet_tls_dist.erl
+++ b/lib/ssl/src/inet_tls_dist.erl
@@ -87,7 +87,8 @@ do_setup(Driver, Kernel, Node, Type, MyNode, LongOrShortNames, SetupTime) ->
case inet:getaddr(Address, Driver:family()) of
{ok, Ip} ->
Timer = dist_util:start_timer(SetupTime),
- case erl_epmd:port_please(Name, Ip) of
+ ErlEpmd = net_kernel:epmd_module(),
+ case ErlEpmd:port_please(Name, Ip) of
{port, TcpPort, Version} ->
?trace("port_please(~p) -> version ~p~n",
[Node,Version]),
diff --git a/lib/ssl/src/ssl_tls_dist_proxy.erl b/lib/ssl/src/ssl_tls_dist_proxy.erl
index 4651687fe6..2e308a15b7 100644
--- a/lib/ssl/src/ssl_tls_dist_proxy.erl
+++ b/lib/ssl/src/ssl_tls_dist_proxy.erl
@@ -116,7 +116,8 @@ handle_call({listen, Driver, Name}, _From, State) ->
{ok, TcpAddress} = get_tcp_address(Socket),
{ok, WorldTcpAddress} = get_tcp_address(World),
{_,Port} = WorldTcpAddress#net_address.address,
- case erl_epmd:register_node(Name, Port) of
+ ErlEpmd = net_kernel:epmd_module(),
+ case ErlEpmd:register_node(Name, Port) of
{ok, Creation} ->
{reply, {ok, {Socket, TcpAddress, Creation}},
State#state{listen={Socket, World}}};
--
cgit v1.2.3
From 8ff06daa90c7c3c599c9e8cbc93fe98c2ed5ebfa Mon Sep 17 00:00:00 2001
From: Magnus Henoch
Date: Wed, 25 May 2016 17:35:11 +0100
Subject: Add tests for -start_epmd and -epmd_module options
For -start_epmd, check that the node starts properly and that we can
ping it.
For -epmd_module, start two nodes that can communicate only because we
supply the correct port number through a command line argument.
---
erts/emulator/test/distribution_SUITE.erl | 69 ++++++++++++++++++++++++++++++-
1 file changed, 67 insertions(+), 2 deletions(-)
diff --git a/erts/emulator/test/distribution_SUITE.erl b/erts/emulator/test/distribution_SUITE.erl
index d0096fb1bc..26780f6017 100644
--- a/erts/emulator/test/distribution_SUITE.erl
+++ b/erts/emulator/test/distribution_SUITE.erl
@@ -55,7 +55,8 @@
bad_dist_ext_receive/1,
bad_dist_ext_process_info/1,
bad_dist_ext_control/1,
- bad_dist_ext_connection_id/1]).
+ bad_dist_ext_connection_id/1,
+ start_epmd_false/1, epmd_module/1]).
%% Internal exports.
-export([sender/3, receiver2/2, dummy_waiter/0, dead_process/0,
@@ -64,6 +65,9 @@
dist_evil_parallel_receiver/0,
sendersender/4, sendersender2/4]).
+%% epmd_module exports
+-export([start_link/0, register_node/2, port_please/2]).
+
suite() ->
[{ct_hooks,[ts_install_cth]},
{timetrap, {minutes, 4}}].
@@ -76,7 +80,8 @@ all() ->
{group, trap_bif}, {group, dist_auto_connect},
dist_parallel_send, atom_roundtrip, unicode_atom_roundtrip, atom_roundtrip_r15b,
contended_atom_cache_entry, contended_unicode_atom_cache_entry,
- bad_dist_structure, {group, bad_dist_ext}].
+ bad_dist_structure, {group, bad_dist_ext},
+ start_epmd_false, epmd_module].
groups() ->
[{bulk_send, [], [bulk_send_small, bulk_send_big, bulk_send_bigbig]},
@@ -1881,6 +1886,66 @@ dmsg_ext(Term) ->
dmsg_bad_atom_cache_ref() ->
[$R, 137].
+start_epmd_false(Config) when is_list(Config) ->
+ %% Start a node with the option -start_epmd false.
+ {ok, OtherNode} = start_node(start_epmd_false, "-start_epmd false"),
+ %% We should be able to ping it, as epmd was started by us:
+ pong = net_adm:ping(OtherNode),
+ stop_node(OtherNode),
+
+ ok.
+
+epmd_module(Config) when is_list(Config) ->
+ %% We need a relay node to test this, since the test node uses the
+ %% standard epmd module.
+ Sock1 = start_relay_node(epmd_module_node1, "-epmd_module " ++ ?MODULE_STRING),
+ Node1 = inet_rpc_nodename(Sock1),
+ %% Ask what port it's listening on - it won't have registered with
+ %% epmd.
+ {ok, {ok, Port1}} = do_inet_rpc(Sock1, application, get_env, [kernel, dist_listen_port]),
+
+ %% Start a second node, passing the port number as a secret
+ %% argument.
+ Sock2 = start_relay_node(epmd_module_node2, "-epmd_module " ++ ?MODULE_STRING
+ ++ " -other_node_port " ++ integer_to_list(Port1)),
+ Node2 = inet_rpc_nodename(Sock2),
+ %% Node 1 can't ping node 2
+ {ok, pang} = do_inet_rpc(Sock1, net_adm, ping, [Node2]),
+ {ok, []} = do_inet_rpc(Sock1, erlang, nodes, []),
+ {ok, []} = do_inet_rpc(Sock2, erlang, nodes, []),
+ %% But node 2 can ping node 1
+ {ok, pong} = do_inet_rpc(Sock2, net_adm, ping, [Node1]),
+ {ok, [Node2]} = do_inet_rpc(Sock1, erlang, nodes, []),
+ {ok, [Node1]} = do_inet_rpc(Sock2, erlang, nodes, []),
+
+ stop_relay_node(Sock2),
+ stop_relay_node(Sock1).
+
+%% epmd_module functions:
+
+start_link() ->
+ ignore.
+
+register_node(_Name, Port) ->
+ %% Save the port number we're listening on.
+ application:set_env(kernel, dist_listen_port, Port),
+ Creation = rand:uniform(3),
+ {ok, Creation}.
+
+port_please(_Name, _Ip) ->
+ case init:get_argument(other_node_port) of
+ error ->
+ %% None specified. Default to 42.
+ Port = 42,
+ Version = 5,
+ {port, Port, Version};
+ {ok, [[PortS]]} ->
+ %% Port number given on command line.
+ Port = list_to_integer(PortS),
+ Version = 5,
+ {port, Port, Version}
+ end.
+
%%% Utilities
timestamp() ->
--
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