Feature: add functions to add + remove dispatch routes

Makefile

@@ -2,7 +2,7 @@
 
 PROJECT = cowboy
 PROJECT_DESCRIPTION = Small, fast, modern HTTP server.
-PROJECT_VERSION = 2.9.0
+PROJECT_VERSION = 2.9.1
 PROJECT_REGISTERED = cowboy_clock
 
 # Options.

src/cowboy.erl

@@ -19,6 +19,9 @@
 -export([stop_listener/1]).
 -export([set_env/3]).
 
+-export([add_routes/2]).
+-export([remove_routes/2]).
+
 %% Internal.
 -export([log/2]).
 -export([log/4]).
@@ -70,6 +73,18 @@ ensure_connection_type(TransOpts) ->
 stop_listener(Ref) ->
 	ranch:stop_listener(Ref).
 
+-spec add_routes(ranch:ref(), cowboy_router:dispatch_rules()) -> ok.
+add_routes(Ref, NewDispatch) ->
+	Opts = #{env := Env0 = #{dispatch := Dispatch}} = ranch:get_protocol_options(Ref),
+	Env1 = Env0#{dispatch => add_routes_(NewDispatch, Dispatch)},
+	ok = ranch:set_protocol_options(Ref, Opts#{env => Env1}).
+
+-spec remove_routes(ranch:ref(), cowboy_router:dispatch_rules()) -> ok.
+remove_routes(Ref, NewDispatch) ->
+	Opts = #{env := Env0 = #{dispatch := Dispatch}} = ranch:get_protocol_options(Ref),
+	Env1 = Env0#{dispatch => remove_routes_(NewDispatch, Dispatch)},
+	ok = ranch:set_protocol_options(Ref, Opts#{env => Env1}).
+
 -spec set_env(ranch:ref(), atom(), any()) -> ok.
 set_env(Ref, Name, Value) ->
 	Opts = ranch:get_protocol_options(Ref),
@@ -103,3 +118,43 @@ log(Level, Format, Args, _) ->
 		debug -> info_msg
 	end,
 	error_logger:Function(Format, Args).
+
+add_routes_([], Dispatch) ->
+	Dispatch;
+add_routes_(Dispatch, []) ->
+	Dispatch;
+add_routes_([Route0 = {HostMatch, CowboyFields, Paths}|Tail], Dispatch0) ->
+	{Route1, Dispatch1} = 
+		case lists:keytake(HostMatch, 1, Dispatch0) of
+			{value, {HostMatch, ExistingCowboyFields, ExistingPaths}, Dispatch} ->
+				Route = {HostMatch, lists:flatten(CowboyFields, ExistingCowboyFields), lists:flatten(Paths, ExistingPaths)},
+				{Route, Dispatch};
+			false ->
+				{Route0, Dispatch0}
+		end,
+	[Route1 | add_routes_(Tail, Dispatch1)].
+
+remove_routes_([], Dispatch) ->
+	Dispatch;
+remove_routes_(_Dispatch, []) ->
+	[];
+remove_routes_([Route0 = {HostMatch, CowboyFields, Paths}|Tail], Dispatch0) ->
+	{Route1, Dispatch1} = 
+		case lists:keytake(HostMatch, 1, Dispatch0) of
+			{value, {HostMatch, ExistingCowboyFields, ExistingPaths}, Dispatch} ->
+				case ExistingPaths -- Paths of
+					[] ->
+						{undefined, Dispatch};
+					NewPaths ->
+						Route = {HostMatch, ExistingCowboyFields -- CowboyFields, NewPaths},
+						{Route, Dispatch}
+				end;
+			false ->
+				{Route0, Dispatch0}
+		end,
+	case Route1 of
+		undefined ->
+			add_routes_(Tail, Dispatch1);
+		_ ->
+			[Route1 | add_routes_(Tail, Dispatch1)]
+	end.

test/misc_SUITE.erl

@@ -21,14 +21,15 @@
 -import(cowboy_test, [gun_open/1]).
 
 all() ->
-	[{group, app}, {group, set_env}|cowboy_test:common_all()].
+	[{group, app}, {group, set_env}, {group, routes}|cowboy_test:common_all()].
 
 groups() ->
 	Common = ct_helper:all(?MODULE)
 		-- [restart_gracefully, set_env, set_env_missing],
 	[
 		{app, [], [restart_gracefully]},
-		{set_env, [parallel], [set_env, set_env_missing]}
+		{set_env, [parallel], [set_env, set_env_missing]},
+		{routes, [parallel], [add_route, remove_route]}
 	|cowboy_test:common_groups(Common)].
 
 init_per_group(Name=app, Config) ->
@@ -37,11 +38,15 @@ init_per_group(Name=app, Config) ->
 	}, Config);
 init_per_group(set_env, Config) ->
 	Config;
+init_per_group(routes, Config) ->
+	Config;
 init_per_group(Name, Config) ->
 	cowboy_test:init_common_groups(Name, Config, ?MODULE).
 
 end_per_group(set_env, _) ->
 	ok;
+end_per_group(routes, _) ->
+	ok;
 end_per_group(Name, _) ->
 	cowboy:stop_listener(Name).
 
@@ -119,3 +124,65 @@ set_env_missing(Config0) ->
 	after
 		cowboy:stop_listener(?FUNCTION_NAME)
 	end.
+
+add_route(Config0) ->
+	doc("Live add a route."),
+	Dispatch = 
+		cowboy_router:compile([{'_', [
+			{"/", hello_h, []}
+		]}]),
+	Config = cowboy_test:init_http(?FUNCTION_NAME, #{
+		env => #{
+			dispatch => Dispatch
+		}
+	}, Config0),
+	try
+		ConnPid1 = gun_open(Config),
+		Ref1 = gun:get(ConnPid1, "/"),
+		{response, _, 200, _} = gun:await(ConnPid1, Ref1),
+		ConnPid2 = gun_open(Config),
+		Ref2 = gun:get(ConnPid2, "/new"),
+		{response, _, 404, _} = gun:await(ConnPid2, Ref2),
+		cowboy:add_routes(?FUNCTION_NAME, cowboy_router:compile([{'_', [
+			{"/new", hello_h, []}
+		]}])),
+		%% Only new connections get the updated environment.
+		ConnPid3 = gun_open(Config),
+		Ref3 = gun:get(ConnPid3, "/new"),
+		{response, _, 200, _} = gun:await(ConnPid3, Ref3)
+	after
+		cowboy:stop_listener(?FUNCTION_NAME)
+	end.
+
+remove_route(Config0) ->
+	doc("Live add a route."),
+	Dispatch = 
+		cowboy_router:compile([{'_', [
+			{"/", hello_h, []},
+			{"/new", hello_h, []}
+		]}]),
+	Config = cowboy_test:init_http(?FUNCTION_NAME, #{
+		env => #{
+			dispatch => Dispatch
+		}
+	}, Config0),
+	try
+		ConnPid1 = gun_open(Config),
+		Ref1 = gun:get(ConnPid1, "/"),
+		{response, _, 200, _} = gun:await(ConnPid1, Ref1),
+		ConnPid2 = gun_open(Config),
+		Ref2 = gun:get(ConnPid2, "/new"),
+		{response, _, 200, _} = gun:await(ConnPid2, Ref2),
+		cowboy:remove_routes(?FUNCTION_NAME, cowboy_router:compile([{'_', [
+			{"/new", hello_h, []}
+		]}])),
+		%% Only new connections get the updated environment.
+		ConnPid3 = gun_open(Config),
+		Ref3 = gun:get(ConnPid3, "/"),
+		{response, _, 200, _} = gun:await(ConnPid3, Ref3),
+		ConnPid4 = gun_open(Config),
+		Ref4 = gun:get(ConnPid4, "/new"),
+		{response, _, 404, _} = gun:await(ConnPid4, Ref4)
+	after
+		cowboy:stop_listener(?FUNCTION_NAME)
+	end.