From c3391bb822f0516975b293bc220e1a44cdb8bc0c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jos=C3=A9=20Valim?= Date: Wed, 9 Jan 2019 12:24:17 +0100 Subject: Add start_distribution to kernel environment Sometimes you may want to start Erlang without any of its distribution services. This commit adds an environment configuration that allows so. Because the servers we don't start here are a subset of the servers not started on minimal mode, we do have a guarantee that the system can still operate as the system operates without those apps on minimal mode. --- lib/kernel/doc/src/kernel_app.xml | 8 ++++ lib/kernel/src/kernel.erl | 72 ++++++++++++++++++--------------- lib/kernel/test/kernel_config_SUITE.erl | 21 ++++++---- 3 files changed, 62 insertions(+), 39 deletions(-) (limited to 'lib') diff --git a/lib/kernel/doc/src/kernel_app.xml b/lib/kernel/doc/src/kernel_app.xml index 15dbdb47dc..78c7319e43 100644 --- a/lib/kernel/doc/src/kernel_app.xml +++ b/lib/kernel/doc/src/kernel_app.xml @@ -369,6 +369,14 @@ MaxT = TickTime + TickTime / 4 performed. This option ensures that global is synchronized.

+ start_distribution = true | false + +

Starts all distribution services, such as rpc, + global, and net_kernel if the parameter is + true. This parameter is to be set to false + for systems who want to disable all distribution functionality.

+

Defaults to true.

+ start_dist_ac = true | false

Starts the dist_ac server if the parameter is diff --git a/lib/kernel/src/kernel.erl b/lib/kernel/src/kernel.erl index c68d04e279..111d103df2 100644 --- a/lib/kernel/src/kernel.erl +++ b/lib/kernel/src/kernel.erl @@ -145,26 +145,11 @@ init([]) -> {ok, {SupFlags, [Code, File, StdError, User, LoggerSup, Config, RefC, SafeSup]}}; _ -> - Rpc = #{id => rex, - start => {rpc, start_link, []}, - restart => permanent, - shutdown => 2000, - type => worker, - modules => [rpc]}, - - Global = #{id => global_name_server, - start => {global, start_link, []}, - restart => permanent, - shutdown => 2000, - type => worker, - modules => [global]}, - - GlGroup = #{id => global_group, - start => {global_group,start_link,[]}, - restart => permanent, - shutdown => 2000, - type => worker, - modules => [global_group]}, + DistChildren = + case application:get_env(kernel, start_distribution) of + {ok, false} -> []; + _ -> start_distribution() + end, InetDb = #{id => inet_db, start => {inet_db, start_link, []}, @@ -173,13 +158,6 @@ init([]) -> type => worker, modules => [inet_db]}, - NetSup = #{id => net_sup, - start => {erl_distribution, start_link, []}, - restart => permanent, - shutdown => infinity, - type => supervisor, - modules => [erl_distribution]}, - SigSrv = #{id => erl_signal_server, start => {gen_event, start_link, [{local, erl_signal_server}]}, restart => permanent, @@ -187,14 +165,11 @@ init([]) -> type => worker, modules => dynamic}, - DistAC = start_dist_ac(), - Timer = start_timer(), {ok, {SupFlags, - [Code, Rpc, Global, InetDb | DistAC] ++ - [NetSup, GlGroup, File, SigSrv, - StdError, User, Config, RefC, SafeSup, LoggerSup] ++ Timer}} + [Code, InetDb | DistChildren] ++ + [File, SigSrv, StdError, User, Config, RefC, SafeSup, LoggerSup] ++ Timer}} end; init(safe) -> SupFlags = #{strategy => one_for_one, @@ -213,6 +188,39 @@ init(safe) -> {ok, {SupFlags, Boot ++ DiskLog ++ Pg2}}. +start_distribution() -> + Rpc = #{id => rex, + start => {rpc, start_link, []}, + restart => permanent, + shutdown => 2000, + type => worker, + modules => [rpc]}, + + Global = #{id => global_name_server, + start => {global, start_link, []}, + restart => permanent, + shutdown => 2000, + type => worker, + modules => [global]}, + + DistAC = start_dist_ac(), + + NetSup = #{id => net_sup, + start => {erl_distribution, start_link, []}, + restart => permanent, + shutdown => infinity, + type => supervisor, + modules => [erl_distribution]}, + + GlGroup = #{id => global_group, + start => {global_group,start_link,[]}, + restart => permanent, + shutdown => 2000, + type => worker, + modules => [global_group]}, + + [Rpc, Global | DistAC] ++ [NetSup, GlGroup]. + start_dist_ac() -> Spec = [#{id => dist_ac, start => {dist_ac,start_link,[]}, diff --git a/lib/kernel/test/kernel_config_SUITE.erl b/lib/kernel/test/kernel_config_SUITE.erl index 9207025a2c..57c44c2498 100644 --- a/lib/kernel/test/kernel_config_SUITE.erl +++ b/lib/kernel/test/kernel_config_SUITE.erl @@ -21,7 +21,8 @@ -include_lib("common_test/include/ct.hrl"). --export([all/0, suite/0,groups/0,init_per_group/2,end_per_group/2, sync/1]). +-export([all/0, suite/0,groups/0,init_per_group/2,end_per_group/2, + start_distribution_false/1, sync/1]). -export([init_per_suite/1, end_per_suite/1]). @@ -30,7 +31,7 @@ suite() -> {timetrap,{minutes,2}}]. all() -> - [sync]. + [sync, start_distribution_false]. groups() -> []. @@ -59,12 +60,9 @@ from(H, [H | T]) -> T; from(H, [_ | T]) -> from(H, T); from(_, []) -> []. -%%----------------------------------------------------------------- -%% Test suite for sync_nodes. This is quite tricky. -%% +%% Test sync_nodes. This is quite tricky. %% Should be started in a CC view with: %% erl -sname XXX where XX not in [cp1, cp2] -%%----------------------------------------------------------------- sync(Conf) when is_list(Conf) -> %% Write a config file Dir = proplists:get_value(priv_dir,Conf), @@ -106,9 +104,18 @@ wait_for_node(Node) -> _Other -> wait_for_node(Node) end. - stop_node(Node) -> M = list_to_atom(lists:concat([Node, [$@], from($@,atom_to_list(node()))])), rpc:cast(M, erlang, halt, []). + +start_distribution_false(Config) when is_list(Config) -> + %% When distribution is disabled, -sname/-name has no effect + Str = os:cmd(ct:get_progname() + ++ " -kernel start_distribution false" + ++ " -sname no_distribution" + ++ " -eval \"erlang:display(node())\"" + ++ " -noshell -s erlang halt"), + "'nonode@nohost'" ++ _ = Str, + ok. -- cgit v1.2.3