refactor: simplify updating the listener

This commit is contained in:
Zhongwen Deng 2022-04-20 01:50:50 +08:00
parent 24e1772532
commit 2b73a80dba
3 changed files with 227 additions and 113 deletions

View File

@ -50,12 +50,14 @@
parse_listener_id/1 parse_listener_id/1
]). ]).
-export([post_config_update/5]). -export([create/2, update/2, remove/1]).
-export([pre_config_update/3, post_config_update/5]).
-export([format_addr/1]). -export([format_addr/1]).
-define(CONF_KEY_PATH, [listeners]). -define(CONF_KEY_PATH, [listeners, '?', '?']).
-define(TYPES_STRING, ["tcp", "ssl", "ws", "wss", "quic"]). -define(TYPES_STRING, ["tcp", "ssl", "ws", "wss", "quic"]).
-define(OPTS(_OverrideTo_), #{rawconf_with_defaults => true, override_to => _OverrideTo_}).
-spec id_example() -> atom(). -spec id_example() -> atom().
id_example() -> 'tcp:default'. id_example() -> 'tcp:default'.
@ -202,7 +204,9 @@ start_listener(Type, ListenerName, #{bind := Bind} = Conf) ->
"Failed to start listener ~ts on ~ts: ~0p~n", "Failed to start listener ~ts on ~ts: ~0p~n",
[ListenerId, BindStr, Reason] [ListenerId, BindStr, Reason]
), ),
error({failed_to_start, ListenerId, BindStr, Reason}) Msg = lists:flatten(io_lib:format("~ts(~ts) : ~p",
[ListenerId, BindStr, element(1, Reason)])),
{error, {failed_to_start, Msg}}
end. end.
%% @doc Restart all listeners %% @doc Restart all listeners
@ -334,55 +338,48 @@ do_start_listener(quic, ListenerName, #{bind := ListenOn} = Opts) ->
{ok, {skipped, quic_app_missing}} {ok, {skipped, quic_app_missing}}
end. end.
delete_authentication(Type, ListenerName, _Conf) -> update(Path, Conf) ->
emqx_authentication:delete_chain(listener_id(Type, ListenerName)). wrap(emqx_conf:update(Path, {update, Conf}, ?OPTS(cluster))).
create(Path, Conf) ->
wrap(emqx_conf:update(Path, {create, Conf}, ?OPTS(cluster))).
remove(Path) ->
wrap(emqx_conf:remove(Path, ?OPTS(cluster))).
wrap({error, {post_config_update,?MODULE, Reason}}) -> {error, Reason};
wrap({error, {pre_config_update,?MODULE, Reason}}) -> {error, Reason};
wrap({error, Reason}) -> {error, Reason};
wrap(Ok) -> Ok.
%% Update the listeners at runtime %% Update the listeners at runtime
post_config_update(_, _Req, NewListeners, OldListeners, _AppEnvs) -> pre_config_update([listeners, Type, Name], {create, NewConf}, undefined) ->
#{added := Added, removed := Removed, changed := Updated} = CertsDir = certs_dir(Type, Name),
diff_listeners(NewListeners, OldListeners), {ok, convert_certs(CertsDir, NewConf)};
try pre_config_update([listeners, _Type, _Name], {create, _NewConf}, _RawConf) ->
perform_listener_changes(fun stop_listener/3, Removed), {error, already_exist};
perform_listener_changes(fun delete_authentication/3, Removed), pre_config_update([listeners, _Type, _Name], {update, _Request}, undefined) ->
perform_listener_changes(fun start_listener/3, Added), {error, not_found};
perform_listener_changes(fun restart_listener/3, Updated) pre_config_update([listeners, Type, Name], {update, Request}, RawConf) ->
catch NewConf = emqx_map_lib:deep_merge(RawConf, Request),
error:{failed_to_start, ListenerId, Bind, Reason} -> CertsDir = certs_dir(Type, Name),
Error = lists:flatten( {ok, convert_certs(CertsDir, NewConf)}.
io_lib:format(
"~ts(~ts) failed with ~ts", post_config_update([listeners, Type, Name], {create, _Request}, NewConf, undefined, _AppEnvs) ->
[ListenerId, Bind, element(1, Reason)] start_listener(Type, Name, NewConf);
) post_config_update([listeners, Type, Name], {update, _Request}, NewConf, OldConf, _AppEnvs) ->
), restart_listener(Type, Name, {OldConf, NewConf});
{error, Error} post_config_update([listeners, _Type, _Name], '$remove', undefined, undefined, _AppEnvs) ->
{error, not_found};
post_config_update([listeners, Type, Name], '$remove', undefined, OldConf, _AppEnvs) ->
case stop_listener(Type, Name, OldConf) of
ok ->
emqx_authentication:delete_chain(listener_id(Type, Name)),
CertsDir = certs_dir(Type, Name),
clear_certs(CertsDir, OldConf);
Err -> Err
end. end.
perform_listener_changes(Action, MapConfs) ->
lists:foreach(
fun({Id, Conf}) ->
{ok, #{type := Type, name := Name}} = parse_listener_id(Id),
Action(Type, Name, Conf)
end,
maps:to_list(MapConfs)
).
diff_listeners(NewListeners, OldListeners) ->
emqx_map_lib:diff_maps(flatten_listeners(NewListeners), flatten_listeners(OldListeners)).
flatten_listeners(Conf0) ->
maps:from_list(
lists:append([
do_flatten_listeners(Type, Conf)
|| {Type, Conf} <- maps:to_list(Conf0)
])
).
do_flatten_listeners(Type, Conf0) ->
[
{listener_id(Type, Name), maps:remove(authentication, Conf)}
|| {Name, Conf} <- maps:to_list(Conf0)
].
esockd_opts(Type, Opts0) -> esockd_opts(Type, Opts0) ->
Opts1 = maps:with([acceptors, max_connections, proxy_protocol, proxy_protocol_timeout], Opts0), Opts1 = maps:with([acceptors, max_connections, proxy_protocol, proxy_protocol_timeout], Opts0),
Limiter = limiter(Opts0), Limiter = limiter(Opts0),
@ -518,7 +515,10 @@ foreach_listeners(Do) ->
lists:foreach( lists:foreach(
fun({Id, LConf}) -> fun({Id, LConf}) ->
{ok, #{type := Type, name := Name}} = parse_listener_id(Id), {ok, #{type := Type, name := Name}} = parse_listener_id(Id),
Do(Type, Name, LConf) case Do(Type, Name, LConf) of
{error, {failed_to_start, _} = Reason} -> error(Reason);
_ -> ok
end
end, end,
list() list()
). ).
@ -552,3 +552,20 @@ parse_bind(#{<<"bind">> := Bind}) ->
{ok, L} -> L; {ok, L} -> L;
{error, _} -> binary_to_integer(Bind) {error, _} -> binary_to_integer(Bind)
end. end.
%% The relative dir for ssl files.
certs_dir(Type, Name) ->
iolist_to_binary(filename:join(["listeners", Type, Name])).
convert_certs(CertsDir, Conf) ->
case emqx_tls_lib:ensure_ssl_files(CertsDir, maps:get(<<"ssl">>, Conf, undefined)) of
{ok, undefined} -> Conf;
{ok, SSL} -> Conf#{<<"ssl">> => SSL};
{error, Reason} ->
?SLOG(error, Reason#{msg => "bad_ssl_config"}),
throw({bad_ssl_config, Reason})
end.
clear_certs(CertsDir, Conf) ->
OldSSL = maps:get(<<"ssl">>, Conf, undefined),
emqx_tls_lib:delete_ssl_files(CertsDir, undefined, OldSSL).

View File

@ -30,9 +30,7 @@
%% for rpc call %% for rpc call
-export([ -export([
do_list_listeners/0, do_list_listeners/0
do_update_listener/2,
do_remove_listener/1
]). ]).
-include_lib("emqx/include/emqx.hrl"). -include_lib("emqx/include/emqx.hrl").
@ -44,8 +42,6 @@
-define(LISTENER_ID_INCONSISTENT, <<"Path and body's listener id not match">>). -define(LISTENER_ID_INCONSISTENT, <<"Path and body's listener id not match">>).
-define(ADDR_PORT_INUSE, <<"Addr port in use">>). -define(ADDR_PORT_INUSE, <<"Addr port in use">>).
-define(OPTS(_OverrideTo_), #{rawconf_with_defaults => true, override_to => _OverrideTo_}).
namespace() -> "listeners". namespace() -> "listeners".
api_spec() -> api_spec() ->
@ -65,7 +61,10 @@ schema("/listeners_status") ->
get => #{ get => #{
tags => [<<"listeners">>], tags => [<<"listeners">>],
desc => <<"List all running node's listeners live status. group by listener type">>, desc => <<"List all running node's listeners live status. group by listener type">>,
responses => #{200 => ?HOCON(?ARRAY(?R_REF(listener_type_status)))} responses => #{200 =>
emqx_dashboard_swagger:schema_with_example(
?ARRAY(?R_REF(listener_type_status)),
listener_type_status_example())}
} }
}; };
schema("/listeners") -> schema("/listeners") ->
@ -78,10 +77,13 @@ schema("/listeners") ->
{type, {type,
?HOCON( ?HOCON(
?ENUM(listeners_type()), ?ENUM(listeners_type()),
#{desc => "Listener type", in => query, required => false} #{desc => "Listener type", in => query, required => false, example => tcp}
)} )}
], ],
responses => #{200 => ?HOCON(?ARRAY(?R_REF(listener_id_status)))} responses => #{200 =>
emqx_dashboard_swagger:schema_with_example(
?ARRAY(?R_REF(listener_id_status)),
listener_id_status_example())}
} }
}; };
schema("/listeners/:id") -> schema("/listeners/:id") ->
@ -92,7 +94,7 @@ schema("/listeners/:id") ->
desc => <<"List all running node's listeners for the specified id.">>, desc => <<"List all running node's listeners for the specified id.">>,
parameters => [?R_REF(listener_id)], parameters => [?R_REF(listener_id)],
responses => #{ responses => #{
200 => ?HOCON(listener_schema(#{bind => true})), 200 => listener_schema(#{bind => true}),
404 => error_codes(['BAD_LISTENER_ID', 'BAD_REQUEST'], ?LISTENER_NOT_FOUND) 404 => error_codes(['BAD_LISTENER_ID', 'BAD_REQUEST'], ?LISTENER_NOT_FOUND)
} }
}, },
@ -100,9 +102,9 @@ schema("/listeners/:id") ->
tags => [<<"listeners">>], tags => [<<"listeners">>],
desc => <<"Update the specified listener on all nodes.">>, desc => <<"Update the specified listener on all nodes.">>,
parameters => [?R_REF(listener_id)], parameters => [?R_REF(listener_id)],
'requestBody' => ?HOCON(listener_schema(#{bind => false}), #{}), 'requestBody' => listener_schema(#{bind => false}),
responses => #{ responses => #{
200 => ?HOCON(listener_schema(#{bind => true}), #{}), 200 => listener_schema(#{bind => true}),
400 => error_codes(['BAD_REQUEST']), 400 => error_codes(['BAD_REQUEST']),
404 => error_codes(['BAD_LISTENER_ID', 'BAD_REQUEST'], ?LISTENER_NOT_FOUND) 404 => error_codes(['BAD_LISTENER_ID', 'BAD_REQUEST'], ?LISTENER_NOT_FOUND)
} }
@ -111,9 +113,9 @@ schema("/listeners/:id") ->
tags => [<<"listeners">>], tags => [<<"listeners">>],
desc => <<"Create the specified listener on all nodes.">>, desc => <<"Create the specified listener on all nodes.">>,
parameters => [?R_REF(listener_id)], parameters => [?R_REF(listener_id)],
'requestBody' => ?HOCON(listener_schema(#{bind => true}), #{}), 'requestBody' => listener_schema(#{bind => true}),
responses => #{ responses => #{
200 => ?HOCON(listener_schema(#{bind => true}), #{}), 200 => listener_schema(#{bind => true}),
400 => error_codes(['BAD_LISTENER_ID', 'BAD_REQUEST']) 400 => error_codes(['BAD_LISTENER_ID', 'BAD_REQUEST'])
} }
}, },
@ -149,8 +151,9 @@ fields(listener_id) ->
{id, {id,
?HOCON(atom(), #{ ?HOCON(atom(), #{
desc => "Listener id", desc => "Listener id",
example => 'tcp:default', example => 'tcp:demo',
validator => fun validate_id/1, validator => fun validate_id/1,
required => true,
in => path in => path
})} })}
]; ];
@ -184,7 +187,10 @@ fields(listener_id_status) ->
fields(listener_id) ++ fields(listener_id) ++
[ [
{enable, ?HOCON(boolean(), #{desc => "Listener enable", required => true})}, {enable, ?HOCON(boolean(), #{desc => "Listener enable", required => true})},
{number, ?HOCON(typerefl:pos_integer(), #{desc => "ListenerId number"})}, {number, ?HOCON(typerefl:pos_integer(), #{desc => "ListenerId counter"})},
{bind, ?HOCON(hoconsc:union([emqx_schema:ip_port(), integer()]),
#{desc => "Listener bind addr", required => true})},
{acceptors, ?HOCON(typerefl:pos_integer(), #{desc => "ListenerId acceptors"})},
{status, ?HOCON(?R_REF(status))}, {status, ?HOCON(?R_REF(status))},
{node_status, ?HOCON(?ARRAY(?R_REF(node_status)))} {node_status, ?HOCON(?ARRAY(?R_REF(node_status)))}
]; ];
@ -202,7 +208,9 @@ fields(Type) ->
Schema. Schema.
listener_schema(Opts) -> listener_schema(Opts) ->
?UNION(lists:map(fun(#{ref := Ref}) -> Ref end, listeners_info(Opts))). emqx_dashboard_swagger:schema_with_example(
?UNION(lists:map(fun(#{ref := Ref}) -> Ref end, listeners_info(Opts))),
tcp_schema_example()).
listeners_type() -> listeners_type() ->
lists:map( lists:map(
@ -266,7 +274,11 @@ validate_id(Id) ->
%% api %% api
listener_type_status(get, _Request) -> listener_type_status(get, _Request) ->
Listeners = maps:to_list(listener_status_by_type(list_listeners(), #{})), Listeners = maps:to_list(listener_status_by_type(list_listeners(), #{})),
List = lists:map(fun({Type, L}) -> L#{type => Type} end, Listeners), List = lists:map(fun({Type, L}) ->
L1 = maps:without([bind, acceptors], L),
L1#{type => Type}
end,
Listeners),
{200, List}. {200, List}.
list_listeners(get, #{query_string := Query}) -> list_listeners(get, #{query_string := Query}) ->
@ -291,15 +303,17 @@ crud_listeners_by_id(get, #{bindings := #{id := Id0}}) ->
crud_listeners_by_id(put, #{bindings := #{id := Id}, body := Body0}) -> crud_listeners_by_id(put, #{bindings := #{id := Id}, body := Body0}) ->
case parse_listener_conf(Body0) of case parse_listener_conf(Body0) of
{Id, Type, Name, Conf} -> {Id, Type, Name, Conf} ->
Key = [listeners, Type, Name], Path = [listeners, Type, Name],
case emqx_conf:get_raw(Key, undefined) of case emqx_conf:get_raw(Path, undefined) of
undefined -> undefined ->
{404, #{code => 'BAD_LISTENER_ID', message => ?LISTENER_NOT_FOUND}}; {404, #{code => 'BAD_LISTENER_ID', message => ?LISTENER_NOT_FOUND}};
PrevConf -> PrevConf ->
MergeConf = emqx_map_lib:deep_merge(PrevConf, Conf), MergeConf = emqx_map_lib:deep_merge(PrevConf, Conf),
case emqx_conf:update(Key, MergeConf, ?OPTS(cluster)) of case emqx_listeners:update(Path, MergeConf) of
{ok, #{raw_config := _RawConf}} -> {ok, #{raw_config := _RawConf}} ->
crud_listeners_by_id(get, #{bindings => #{id => Id}}); crud_listeners_by_id(get, #{bindings => #{id => Id}});
{error, not_found} ->
{404, #{code => 'BAD_LISTENER_ID', message => ?LISTENER_NOT_FOUND}};
{error, Reason} -> {error, Reason} ->
{400, #{code => 'BAD_REQUEST', message => err_msg(Reason)}} {400, #{code => 'BAD_REQUEST', message => err_msg(Reason)}}
end end
@ -312,18 +326,15 @@ crud_listeners_by_id(put, #{bindings := #{id := Id}, body := Body0}) ->
crud_listeners_by_id(post, #{bindings := #{id := Id}, body := Body0}) -> crud_listeners_by_id(post, #{bindings := #{id := Id}, body := Body0}) ->
case parse_listener_conf(Body0) of case parse_listener_conf(Body0) of
{Id, Type, Name, Conf} -> {Id, Type, Name, Conf} ->
Key = [listeners, Type, Name], Path = [listeners, Type, Name],
case emqx_conf:get(Key, undefined) of case emqx_listeners:create(Path, Conf) of
undefined ->
case emqx_conf:update([listeners, Type, Name], Conf, ?OPTS(cluster)) of
{ok, #{raw_config := _RawConf}} -> {ok, #{raw_config := _RawConf}} ->
crud_listeners_by_id(get, #{bindings => #{id => Id}}); crud_listeners_by_id(get, #{bindings => #{id => Id}});
{error, already_exist} ->
{400, #{code => 'BAD_LISTENER_ID', message => <<"Already Exist">>}};
{error, Reason} -> {error, Reason} ->
{400, #{code => 'BAD_REQUEST', message => err_msg(Reason)}} {400, #{code => 'BAD_REQUEST', message => err_msg(Reason)}}
end; end;
_ ->
{400, #{code => 'BAD_LISTENER_ID', message => <<"Already Exist">>}}
end;
{error, Reason} -> {error, Reason} ->
{400, #{code => 'BAD_REQUEST', message => err_msg(Reason)}}; {400, #{code => 'BAD_REQUEST', message => err_msg(Reason)}};
_ -> _ ->
@ -331,8 +342,9 @@ crud_listeners_by_id(post, #{bindings := #{id := Id}, body := Body0}) ->
end; end;
crud_listeners_by_id(delete, #{bindings := #{id := Id}}) -> crud_listeners_by_id(delete, #{bindings := #{id := Id}}) ->
{ok, #{type := Type, name := Name}} = emqx_listeners:parse_listener_id(Id), {ok, #{type := Type, name := Name}} = emqx_listeners:parse_listener_id(Id),
case emqx_conf:remove([listeners, Type, Name], ?OPTS(cluster)) of case emqx_listeners:remove([listeners, Type, Name]) of
{ok, _} -> {204}; {ok, _} -> {204};
{error, not_found} -> {204};
{error, Reason} -> {400, #{code => 'BAD_REQUEST', message => err_msg(Reason)}} {error, Reason} -> {400, #{code => 'BAD_REQUEST', message => err_msg(Reason)}}
end. end.
@ -465,23 +477,6 @@ do_list_listeners() ->
<<"listeners">> => Listeners <<"listeners">> => Listeners
}. }.
-spec do_update_listener(string(), emqx_config:update_request()) ->
{ok, map()} | {error, _}.
do_update_listener(Id, Config) ->
{ok, #{type := Type, name := Name}} = emqx_listeners:parse_listener_id(Id),
case emqx:update_config([listeners, Type, Name], Config, ?OPTS(local)) of
{ok, #{raw_config := RawConf}} -> {ok, RawConf};
{error, Reason} -> {error, Reason}
end.
-spec do_remove_listener(string()) -> ok.
do_remove_listener(Id) ->
{ok, #{type := Type, name := Name}} = emqx_listeners:parse_listener_id(Id),
case emqx:remove_config([listeners, Type, Name], ?OPTS(local)) of
{ok, _} -> ok;
{error, Reason} -> error(Reason)
end.
wrap_rpc({badrpc, Reason}) -> wrap_rpc({badrpc, Reason}) ->
{error, Reason}; {error, Reason};
wrap_rpc(Res) -> wrap_rpc(Res) ->
@ -492,7 +487,9 @@ format_status(Key, Node, Listener, Acc) ->
<<"id">> := Id, <<"id">> := Id,
<<"running">> := Running, <<"running">> := Running,
<<"max_connections">> := MaxConnections, <<"max_connections">> := MaxConnections,
<<"current_connections">> := CurrentConnections <<"current_connections">> := CurrentConnections,
<<"acceptors">> := Acceptors,
<<"bind">> := Bind
} = Listener, } = Listener,
GroupKey = maps:get(Key, Listener), GroupKey = maps:get(Key, Listener),
case maps:find(GroupKey, Acc) of case maps:find(GroupKey, Acc) of
@ -501,6 +498,8 @@ format_status(Key, Node, Listener, Acc) ->
GroupKey => #{ GroupKey => #{
enable => Running, enable => Running,
ids => [Id], ids => [Id],
acceptors => Acceptors,
bind => Bind,
status => #{ status => #{
max_connections => MaxConnections, max_connections => MaxConnections,
current_connections => CurrentConnections current_connections => CurrentConnections
@ -555,6 +554,116 @@ format_status(Key, Node, Listener, Acc) ->
} }
end. end.
max_conn(_Int1, infinity) -> infinity; max_conn(_Int1, <<"infinity">>) -> <<"infinity">>;
max_conn(infinity, _Int) -> infinity; max_conn(<<"infinity">>, _Int) -> <<"infinity">>;
max_conn(Int1, Int2) -> Int1 + Int2. max_conn(Int1, Int2) -> Int1 + Int2.
listener_type_status_example() ->
[
#{
enable => false,
ids => ["tcp:demo"],
node_status => #{
'emqx@127.0.0.1' => #{
current_connections => 11,
max_connections => 1024000},
'emqx@127.0.0.2' => #{
current_connections => 10,
max_connections => 1024000}
},
status => #{
current_connections => 21,
max_connections => 2048000
},
type => tcp
},
#{
enable => false,
ids => ["ssl:default"],
node_status => #{
'emqx@127.0.0.1' => #{
current_connections => 31,
max_connections => infinity},
'emqx@127.0.0.2' => #{
current_connections => 40,
max_connections => infinity}
},
status => #{
current_connections => 71,
max_connections => infinity
},
type => ssl
}
].
listener_id_status_example() ->
[
#{
acceptors => 16,
bind => <<"0.0.0.0:1884">>,
enable => true,
id => <<"tcp:demo">>,
node_status => #{
'emqx@127.0.0.1' => #{
current_connections => 100,
max_connections => 1024000
},
'emqx@127.0.0.2' => #{
current_connections => 101,
max_connections => 1024000
}
},
number => 2,
status => #{
current_connections => 201,
max_connections => 2048000
}
},
#{
acceptors => 32,
bind => <<"0.0.0.0:1883">>,
enable => true,
id => <<"tcp:default">>,
node_status => #{
'emqx@127.0.0.1' => #{
current_connections => 300,
max_connections => infinity
},
'emqx@127.0.0.2' => #{
current_connections => 201,
max_connections => infinity
}
},
number => 2,
status => #{
current_connections => 501,
max_connections => infinity
}
}
].
tcp_schema_example() ->
#{
acceptors => 16,
access_rules => ["allow all"],
bind => <<"0.0.0.0:1884">>,
current_connections => 10240,
id => <<"tcp:demo">>,
max_connections => 204800,
mountpoint => <<"/">>,
proxy_protocol => false,
proxy_protocol_timeout => <<"3s">>,
running => true,
tcp => #{
active_n => 100,
backlog => 1024,
buffer => <<"4KB">>,
high_watermark => <<"1MB">>,
nodelay => false,
reuseaddr => true,
send_timeout => <<"15s">>,
send_timeout_close => true
},
type => tcp,
zone => default
}.

View File

@ -26,9 +26,6 @@
list_subscriptions/1, list_subscriptions/1,
list_listeners/1, list_listeners/1,
remove_listener/2,
update_listener/3,
subscribe/3, subscribe/3,
unsubscribe/3, unsubscribe/3,
@ -58,15 +55,6 @@ list_subscriptions(Node) ->
list_listeners(Node) -> list_listeners(Node) ->
rpc:call(Node, emqx_mgmt_api_listeners, do_list_listeners, []). rpc:call(Node, emqx_mgmt_api_listeners, do_list_listeners, []).
-spec remove_listener(node(), string()) -> ok | {badrpc, _}.
remove_listener(Node, Id) ->
rpc:call(Node, emqx_mgmt_api_listeners, do_remove_listener, [Id]).
-spec update_listener(node(), atom(), emqx_config:update_request()) ->
{ok, map()} | {error, _} | {badrpc, _}.
update_listener(Node, Id, Config) ->
rpc:call(Node, emqx_mgmt_api_listeners, do_update_listener, [Id, Config]).
-spec subscribe(node(), emqx_types:clientid(), emqx_types:topic_filters()) -> -spec subscribe(node(), emqx_types:clientid(), emqx_types:topic_filters()) ->
{subscribe, _} | {error, atom()} | {badrpc, _}. {subscribe, _} | {error, atom()} | {badrpc, _}.
subscribe(Node, ClientId, TopicTables) -> subscribe(Node, ClientId, TopicTables) ->