Skip to content

fix: supervise the cowboy listener instead of starting it as a side effect #389

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
Taure wants to merge 1 commit into
base: master
Choose a base branch
from
Open

fix: supervise the cowboy listener instead of starting it as a side effect #389

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
124 changes: 68 additions & 56 deletions src/nova_sup.erl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,10 @@
%% Supervisor callbacks
-export([init/1]).

-ifdef(TEST).
-export([listener_child_spec/1, clear_child_spec/3, tls_child_spec/3]).
-endif.

-include_lib("kernel/include/logger.hrl").
-include("../include/nova.hrl").

Expand Down Expand Up @@ -81,10 +85,13 @@ init([]) ->
_ -> Children0
end,

setup_cowboy(Configuration),

UseStacktrace = application:get_env(nova, use_stacktrace, false),
persistent_term:put(nova_use_stacktrace, UseStacktrace),

{ok, {SupFlags, Children}}.
%% The cowboy/ranch listener is a supervised child rather than a side
%% effect, so a failed bind (e.g. eaddrinuse) fails init/1 and surfaces
%% through application:start/1 instead of being logged and ignored.
{ok, {SupFlags, Children ++ cowboy_childspecs(Configuration)}}.

%%%===================================================================
%%% Internal functions
Expand All @@ -103,25 +110,18 @@ child(Id, Type, Mod) ->
child(Id, Mod) ->
child(Id, worker, Mod).

setup_cowboy(Configuration) ->
case start_cowboy(Configuration) of
{ok, App, Host, Port} ->
Host0 = inet:ntoa(Host),
CowboyVersion = get_version(cowboy),
NovaVersion = get_version(nova),
UseStacktrace = application:get_env(nova, use_stacktrace, false),
persistent_term:put(nova_use_stacktrace, UseStacktrace),
?LOG_NOTICE(#{msg => <<"Nova is running">>,
url => unicode:characters_to_binary(io_lib:format("http://~s:~B", [Host0, Port])),
cowboy_version => CowboyVersion, nova_version => NovaVersion, app => App});
{error, Error} ->
?LOG_ERROR(#{msg => <<"Cowboy could not start">>, reason => Error})
end.

-spec start_cowboy(Configuration :: map()) ->
{ok, BootstrapApp :: atom(), Host :: string() | {integer(), integer(), integer(), integer()},
Port :: integer()} | {error, Reason :: any()}.
start_cowboy(Configuration) ->
cowboy_childspecs(Configuration) ->
{ChildSpec, App, Host, Port} = listener_child_spec(Configuration),
Host0 = inet:ntoa(Host),
?LOG_NOTICE(#{msg => <<"Nova is running">>,
url => unicode:characters_to_binary(io_lib:format("http://~s:~B", [Host0, Port])),
cowboy_version => get_version(cowboy), nova_version => get_version(nova), app => App}),
[ChildSpec].

-spec listener_child_spec(Configuration :: map()) ->
{supervisor:child_spec(), BootstrapApp :: atom(),
Host :: string() | {integer(), integer(), integer(), integer()}, Port :: integer()}.
listener_child_spec(Configuration) ->
Middlewares = [
nova_router, %% Lookup routes
nova_plugin_handler, %% Handle pre-request plugins
Expand Down Expand Up @@ -166,54 +166,66 @@ start_cowboy(Configuration) ->
case maps:get(use_ssl, Configuration, false) of
false ->
Port = maps:get(port, Configuration, ?NOVA_STD_PORT),
case cowboy:start_clear(
?NOVA_LISTENER,
[{port, Port},
{ip, Host}],
CowboyOptions2) of
{ok, _Pid} ->
{ok, BootstrapApp, Host, Port};
Error ->
Error
end;
ChildSpec = clear_child_spec(?NOVA_LISTENER, [{port, Port}, {ip, Host}], CowboyOptions2),
{ChildSpec, BootstrapApp, Host, Port};
_ ->
case maps:get(ca_cert, Configuration, undefined) of
undefined ->
Port = maps:get(ssl_port, Configuration, ?NOVA_STD_SSL_PORT),
SSLOptions = maps:get(ssl_options, Configuration, #{}),
TransportOpts = maps:put(port, Port, SSLOptions),
TransportOpts1 = maps:put(ip, Host, TransportOpts),

case cowboy:start_tls(
?NOVA_LISTENER, maps:to_list(TransportOpts1), CowboyOptions2) of
{ok, _Pid} ->
?LOG_NOTICE(#{msg => <<"Nova starting SSL">>, port => Port}),
{ok, BootstrapApp, Host, Port};
Error ->
?LOG_ERROR(#{msg => <<"Could not start cowboy with SSL">>, reason => Error}),
Error
end;
?LOG_NOTICE(#{msg => <<"Nova starting SSL">>, port => Port}),
ChildSpec = tls_child_spec(?NOVA_LISTENER, maps:to_list(TransportOpts1), CowboyOptions2),
{ChildSpec, BootstrapApp, Host, Port};
CACert ->
Cert = maps:get(cert, Configuration),
Port = maps:get(ssl_port, Configuration, ?NOVA_STD_SSL_PORT),
?LOG_DEPRECATED(<<"0.10.3">>, <<"Use of use_ssl is deprecated, use ssl instead">>),
case cowboy:start_tls(
?NOVA_LISTENER, [
{port, Port},
{ip, Host},
{certfile, Cert},
{cacertfile, CACert}
],
CowboyOptions2) of
{ok, _Pid} ->
?LOG_NOTICE(#{msg => <<"Nova starting SSL">>, port => Port}),
{ok, BootstrapApp, Host, Port};
Error ->
Error
end
?LOG_NOTICE(#{msg => <<"Nova starting SSL">>, port => Port}),
ChildSpec = tls_child_spec(?NOVA_LISTENER,
[{port, Port}, {ip, Host},
{certfile, Cert}, {cacertfile, CACert}],
CowboyOptions2),
{ChildSpec, BootstrapApp, Host, Port}
end
end.

%% These mirror cowboy:start_clear/3 and cowboy:start_tls/3 (cowboy 2.15) but
%% yield a supervisor:child_spec/0 via ranch:child_spec/5 so the listener lives
%% in nova's supervision tree instead of being started as a side effect. Keep
%% the option transforms in listener_opts/2 in sync if the cowboy pin changes.
clear_child_spec(Ref, TransOpts0, ProtoOpts0) ->
{TransOpts, ProtoOpts} = listener_opts(TransOpts0, ProtoOpts0),
ranch:child_spec(Ref, ranch_tcp, TransOpts, cowboy_clear, ProtoOpts).

tls_child_spec(Ref, TransOpts0, ProtoOpts0) ->
{TransOpts, ProtoOpts} = listener_opts(TransOpts0, ProtoOpts0),
ranch:child_spec(Ref, ranch_ssl, TransOpts, cowboy_tls, ProtoOpts).

listener_opts(TransOpts0, ProtoOpts0) ->
TransOpts1 = ranch:normalize_opts(TransOpts0),
{TransOpts2, DynamicBuffer} = ensure_dynamic_buffer(TransOpts1, ProtoOpts0),
{TransOpts, ConnectionType} = ensure_connection_type(TransOpts2),
{TransOpts, ProtoOpts0#{connection_type => ConnectionType, dynamic_buffer => DynamicBuffer}}.

ensure_connection_type(TransOpts = #{connection_type := ConnectionType}) ->
{TransOpts, ConnectionType};
ensure_connection_type(TransOpts) ->
{TransOpts#{connection_type => supervisor}, supervisor}.

ensure_dynamic_buffer(TransOpts, #{dynamic_buffer := DynamicBuffer}) ->
{TransOpts, DynamicBuffer};
ensure_dynamic_buffer(TransOpts = #{socket_opts := SocketOpts}, _) ->
case proplists:get_value(buffer, SocketOpts, undefined) of
undefined ->
{TransOpts#{socket_opts => [{buffer, 512} | SocketOpts]}, {512, 131072}};
_ ->
{TransOpts, false}
end;
ensure_dynamic_buffer(TransOpts, _) ->
{TransOpts, false}.



get_version(Application) ->
Expand Down
50 changes: 50 additions & 0 deletions test/nova_sup_tests.erl
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,50 @@
-module(nova_sup_tests).
-include_lib("eunit/include/eunit.hrl").

%% The listener is a supervisor child spec, not a side effect.
child_spec_is_supervised_test() ->
Spec = nova_sup:clear_child_spec(shape_ref, [{port, 0}], #{}),
?assertEqual({ranch_embedded_sup, shape_ref}, maps:get(id, Spec)),
?assertEqual(supervisor, maps:get(type, Spec)),
{ranch_embedded_sup, start_link, [shape_ref, ranch_tcp, TransOpts, cowboy_clear, ProtoOpts]} =
maps:get(start, Spec),
?assertEqual(supervisor, maps:get(connection_type, TransOpts)),
?assertEqual(supervisor, maps:get(connection_type, ProtoOpts)).

tls_child_spec_uses_ssl_transport_test() ->
Spec = nova_sup:tls_child_spec(tls_ref, [{port, 0}], #{}),
{ranch_embedded_sup, start_link, [tls_ref, ranch_ssl, _, cowboy_tls, _]} = maps:get(start, Spec).

listener_lifecycle_test_() ->
{setup,
fun() ->
{ok, Apps} = application:ensure_all_started(cowboy),
Apps
end,
fun(Apps) -> [application:stop(A) || A <- lists:reverse(Apps)] end,
[
fun binds_on_free_port/0,
fun fails_loudly_on_busy_port/0
]}.

%% A free port yields a live listener process.
binds_on_free_port() ->
Spec = nova_sup:clear_child_spec(free_ref, [{port, 0}, {ip, {127, 0, 0, 1}}], #{}),
{M, F, A} = maps:get(start, Spec),
Result = erlang:apply(M, F, A),
?assertMatch({ok, _}, Result),
{ok, Pid} = Result,
?assert(is_process_alive(Pid)),
unlink(Pid),
exit(Pid, shutdown).

%% A busy port fails the start instead of being swallowed.
fails_loudly_on_busy_port() ->
{ok, LSock} = gen_tcp:listen(0, [{ip, {127, 0, 0, 1}}]),
{ok, Port} = inet:port(LSock),
Spec = nova_sup:clear_child_spec(busy_ref, [{port, Port}, {ip, {127, 0, 0, 1}}], #{}),
{M, F, A} = maps:get(start, Spec),
process_flag(trap_exit, true),
Result = erlang:apply(M, F, A),
?assertMatch({error, _}, Result),
gen_tcp:close(LSock).
Loading