feat(testing): Multinode testing helper

apps/emqx/test/emqx_common_test_helpers.erl

@@ -38,25 +38,32 @@
 ]).
 
 -export([
-    ensure_mnesia_stopped/0,
-    wait_for/4,
     change_emqx_opts/1,
     change_emqx_opts/2,
-    client_ssl_twoway/0,
-    client_ssl_twoway/1,
     client_ssl/0,
     client_ssl/1,
-    wait_mqtt_payload/1,
+    client_ssl_twoway/0,
-    not_wait_mqtt_payload/1,
+    client_ssl_twoway/1,
-    render_config_file/2,
+    ensure_mnesia_stopped/0,
-    read_schema_configs/2,
+    ensure_quic_listener/2,
+    is_tcp_server_available/2,
+    is_tcp_server_available/3,
     load_config/2,
     load_config/3,
-    is_tcp_server_available/2,
+    not_wait_mqtt_payload/1,
-    is_tcp_server_available/3
+    read_schema_configs/2,
+    render_config_file/2,
+    wait_for/4,
+    wait_mqtt_payload/1
 ]).
 
--export([ensure_quic_listener/2]).
+-export([
+    emqx_cluster/1,
+    emqx_cluster/2,
+    start_epmd/0,
+    start_slave/2,
+    stop_slave/1
+]).
 
 -define(CERTS_PATH(CertName), filename:join(["etc", "certs", CertName])).
 
@@ -542,3 +549,248 @@ ensure_quic_listener(Name, UdpPort) ->
         ok -> ok;
         {error, {already_started, _Pid}} -> ok
     end.
+
+%%
+%% Clusterisation and multi-node testing
+%%
+
+emqx_cluster(Specs) ->
+    emqx_cluster(Specs, #{}).
+
+emqx_cluster(Specs, CommonOpts) when is_list(CommonOpts) ->
+    emqx_cluster(Specs, maps:from_list(CommonOpts));
+emqx_cluster(Specs0, CommonOpts) ->
+    Specs1 = lists:zip(Specs0, lists:seq(1, length(Specs0))),
+    Specs = expand_node_specs(Specs1, CommonOpts),
+    CoreNodes = [node_name(Name) || {{core, Name, _}, _} <- Specs],
+    %% Assign grpc ports:
+    GenRpcPorts = maps:from_list([
+        {node_name(Name), {tcp, gen_rpc_port(base_port(Num))}}
+     || {{_, Name, _}, Num} <- Specs
+    ]),
+    %% Set the default node of the cluster:
+    JoinTo =
+        case CoreNodes of
+            [First | _] -> First;
+            _ -> undefined
+        end,
+    [
+        {Name,
+            merge_opts(Opts, #{
+                base_port => base_port(Number),
+                join_to => JoinTo,
+                env => [
+                    {mria, core_nodes, CoreNodes},
+                    {mria, node_role, Role},
+                    {gen_rpc, client_config_per_node, {internal, GenRpcPorts}}
+                ]
+            })}
+     || {{Role, Name, Opts}, Number} <- Specs
+    ].
+
+%% Lower level starting API
+start_slave(Name, Opts) ->
+    {ok, Node} = ct_slave:start(
+        list_to_atom(atom_to_list(Name) ++ "@" ++ host()),
+        [
+            {kill_if_fail, true},
+            {monitor_master, true},
+            {init_timeout, 10000},
+            {startup_timeout, 10000},
+            {erl_flags, erl_flags()}
+        ]
+    ),
+
+    pong = net_adm:ping(Node),
+    setup_node(Node, Opts),
+    Node.
+
+%% Node stopping
+stop_slave(Node) ->
+    ct_slave:stop(Node).
+
+%% EPMD starting
+start_epmd() ->
+    [] = os:cmd("\"" ++ epmd_path() ++ "\" -daemon"),
+    ok.
+
+epmd_path() ->
+    case os:find_executable("epmd") of
+        false ->
+            ct:pal(critical, "Could not find epmd.~n"),
+            exit(epmd_not_found);
+        GlobalEpmd ->
+            GlobalEpmd
+    end.
+
+%% Node initialization
+
+setup_node(Node, Opts) when is_list(Opts) ->
+    setup_node(Node, maps:from_list(Opts));
+setup_node(Node, Opts) when is_map(Opts) ->
+    %% Default base port is selected upon Node from 1100 to 65530 with step 10
+    BasePort = maps:get(base_port, Opts, 1100 + erlang:phash2(Node, 6553 - 110) * 10),
+    Apps = maps:get(apps, Opts, []),
+    StartApps = maps:get(start_apps, Opts, true),
+    JoinTo = maps:get(join_to, Opts, undefined),
+    EnvHandler = maps:get(env_handler, Opts, fun(_) -> ok end),
+    ConfigureGenRpc = maps:get(configure_gen_rpc, Opts, true),
+    LoadSchema = maps:get(load_schema, Opts, true),
+    LoadApps = maps:get(load_apps, Opts, [gen_rpc, emqx, ekka, mria] ++ Apps),
+    Env = maps:get(env, Opts, []),
+    Conf = maps:get(conf, Opts, []),
+    ListenerPorts = maps:get(listener_ports, Opts, [
+        {Type, listener_port(BasePort, Type)}
+     || Type <- [tcp, ssl, ws, wss]
+    ]),
+
+    %% Load env before doing anything to avoid overriding
+    [ok = rpc:call(Node, application, load, [App]) || App <- LoadApps],
+
+    %% Needs to be set explicitly because ekka:start() (which calls `gen`) is called without Handler
+    %% in emqx_common_test_helpers:start_apps(...)
+    ConfigureGenRpc andalso
+        begin
+            ok = rpc:call(Node, application, set_env, [
+                gen_rpc, tcp_server_port, gen_rpc_port(BasePort)
+            ]),
+            ok = rpc:call(Node, application, set_env, [gen_rpc, port_discovery, manual])
+        end,
+
+    %% Setting env before starting any applications
+    [
+        ok = rpc:call(Node, application, set_env, [Application, Key, Value])
+     || {Application, Key, Value} <- Env
+    ],
+
+    %% Here we start the apps
+    EnvHandlerForRpc =
+        fun(App) ->
+            %% We load configuration, and than set the special enviroment variable
+            %% which says that emqx shouldn't load configuration at startup
+            %% Otherwise, configuration get's loaded and all preset env in envhandler is lost
+            LoadSchema andalso
+                begin
+                    emqx_config:init_load(emqx_schema),
+                    application:set_env(emqx, init_config_load_done, true)
+                end,
+
+            %% Need to set this otherwise listeners will conflict between each other
+            [
+                ok = emqx_config:put([listeners, Type, default, bind], {
+                    {127, 0, 0, 1}, Port
+                })
+             || {Type, Port} <- ListenerPorts
+            ],
+
+            [ok = emqx_config:put(KeyPath, Value) || {KeyPath, Value} <- Conf],
+            ok = EnvHandler(App),
+            ok
+        end,
+
+    StartApps andalso
+        begin
+            ok = rpc:call(Node, emqx_common_test_helpers, start_apps, [Apps, EnvHandlerForRpc])
+        end,
+
+    %% Join the cluster if JoinTo is specified
+    case JoinTo of
+        undefined ->
+            ok;
+        _ ->
+            case rpc:call(Node, ekka, join, [JoinTo]) of
+                ok ->
+                    ok;
+                ignore ->
+                    ok;
+                Err ->
+                    stop_slave(Node),
+                    error({failed_to_join_cluster, #{node => Node, error => Err}})
+            end
+    end,
+    ok.
+
+%% Helpers
+
+node_name(Name) ->
+    list_to_atom(lists:concat([Name, "@", host()])).
+
+gen_node_name(Num) ->
+    list_to_atom("autocluster_node" ++ integer_to_list(Num)).
+
+host() ->
+    [_, Host] = string:tokens(atom_to_list(node()), "@"),
+    Host.
+
+merge_opts(Opts1, Opts2) ->
+    maps:merge_with(
+        fun
+            (env, Env1, Env2) -> lists:usort(Env2 ++ Env1);
+            (conf, Conf1, Conf2) -> lists:usort(Conf2 ++ Conf1);
+            (apps, Apps1, Apps2) -> lists:usort(Apps2 ++ Apps1);
+            (load_apps, Apps1, Apps2) -> lists:usort(Apps2 ++ Apps1);
+            (_Option, _Old, Value) -> Value
+        end,
+        Opts1,
+        Opts2
+    ).
+
+erl_flags() ->
+    %% One core and redirecting logs to master
+    "+S 1:1 -master " ++ atom_to_list(node()) ++ " " ++ ebin_path().
+
+ebin_path() ->
+    string:join(["-pa" | lists:filter(fun is_lib/1, code:get_path())], " ").
+
+is_lib(Path) ->
+    string:prefix(Path, code:lib_dir()) =:= nomatch andalso
+        string:str(Path, "_build/default/plugins") =:= 0.
+
+%% Ports
+
+base_port(Number) ->
+    10000 + Number * 100.
+
+gen_rpc_port(BasePort) ->
+    BasePort - 1.
+
+listener_port(BasePort, tcp) ->
+    BasePort;
+listener_port(BasePort, ssl) ->
+    BasePort + 1;
+listener_port(BasePort, quic) ->
+    BasePort + 2;
+listener_port(BasePort, ws) ->
+    BasePort + 3;
+listener_port(BasePort, wss) ->
+    BasePort + 4.
+
+%% Autocluster helpers
+
+expand_node_specs(Specs, CommonOpts) ->
+    lists:map(
+        fun({Spec, Num}) ->
+            {
+                case Spec of
+                    core ->
+                        {core, gen_node_name(Num), CommonOpts};
+                    replicant ->
+                        {replicant, gen_node_name(Num), CommonOpts};
+                    {Role, Name} when is_atom(Name) ->
+                        {Role, Name, CommonOpts};
+                    {Role, Opts} when is_list(Opts) ->
+                        Opts1 = maps:from_list(Opts),
+                        {Role, gen_node_name(Num), merge_opts(CommonOpts, Opts1)};
+                    {Role, Name, Opts} when is_list(Opts) ->
+                        Opts1 = maps:from_list(Opts),
+                        {Role, Name, merge_opts(CommonOpts, Opts1)};
+                    {Role, Opts} ->
+                        {Role, gen_node_name(Num), merge_opts(CommonOpts, Opts)};
+                    {Role, Name, Opts} ->
+                        {Role, Name, merge_opts(CommonOpts, Opts)}
+                end,
+                Num
+            }
+        end,
+        Specs
+    ).

apps/emqx/test/emqx_router_helper_SUITE.erl

@@ -35,7 +35,7 @@ init_per_suite(Config) ->
             ignored ->
                 %% calling `net_kernel:start' without `epmd'
                 %% running will result in a failure.
-                start_epmd(),
+                emqx_common_test_helpers:start_epmd(),
                 {ok, Pid} = net_kernel:start(['test@127.0.0.1', longnames]),
                 Pid;
             _ ->
@@ -60,7 +60,7 @@ init_per_testcase(TestCase, Config) when
     TestCase =:= t_cleanup_monitor_node_down
 ->
     ok = snabbkaffe:start_trace(),
-    Slave = start_slave(some_node),
+    Slave = emqx_common_test_helpers:start_slave(some_node, []),
     [{slave, Slave} | Config];
 init_per_testcase(_TestCase, Config) ->
     Config.
@@ -71,7 +71,7 @@ end_per_testcase(TestCase, Config) when
     TestCase =:= t_cleanup_monitor_node_down
 ->
     Slave = ?config(slave, Config),
-    stop_slave(Slave),
+    emqx_common_test_helpers:stop_slave(Slave),
     mria:transaction(?ROUTE_SHARD, fun() -> mnesia:clear_table(?ROUTE_TAB) end),
     snabbkaffe:stop(),
     ok;
@@ -120,7 +120,7 @@ t_cleanup_monitor_node_down(Config) ->
     emqx_router:add_route(<<"d/e/f">>, node()),
     ?assertMatch([_, _], emqx_router:topics()),
     ?wait_async_action(
-        stop_slave(Slave),
+        emqx_common_test_helpers:stop_slave(Slave),
         #{?snk_kind := emqx_router_helper_cleanup_done, node := Slave},
         1_000
     ),
@@ -130,39 +130,3 @@ t_message(_) ->
     ?ROUTER_HELPER ! testing,
     gen_server:cast(?ROUTER_HELPER, testing),
     gen_server:call(?ROUTER_HELPER, testing).
-
-%%------------------------------------------------------------------------------
-%% Internal functions
-%%------------------------------------------------------------------------------
-
-start_epmd() ->
-    [] = os:cmd("\"" ++ epmd_path() ++ "\" -daemon"),
-    ok.
-
-epmd_path() ->
-    case os:find_executable("epmd") of
-        false ->
-            ct:pal(critical, "Could not find epmd.~n"),
-            exit(epmd_not_found);
-        GlobalEpmd ->
-            GlobalEpmd
-    end.
-
-start_slave(Name) ->
-    % We want VMs to only occupy a single core
-    CommonBeamOpts = "+S 1:1 ",
-    {ok, Node} = slave:start_link(host(), Name, CommonBeamOpts ++ ebin_path()),
-    Node.
-
-stop_slave(Node) ->
-    slave:stop(Node).
-
-host() ->
-    [_, Host] = string:tokens(atom_to_list(node()), "@"),
-    Host.
-
-ebin_path() ->
-    string:join(["-pa" | lists:filter(fun is_lib/1, code:get_path())], " ").
-
-is_lib(Path) ->
-    string:prefix(Path, code:lib_dir()) =:= nomatch.

apps/emqx_conf/test/emqx_conf_app_SUITE.erl

@@ -28,17 +28,18 @@ all() ->
     emqx_common_test_helpers:all(?MODULE).
 
 t_copy_conf_override_on_restarts(_Config) ->
+    net_kernel:start(['master@127.0.0.1', longnames]),
     ct:timetrap({seconds, 120}),
     snabbkaffe:fix_ct_logging(),
     Cluster = cluster([core, core, core]),
+
+    %% 1. Start all nodes
+    Nodes = start_cluster(Cluster),
     try
-        %% 1. Start all nodes
-        Nodes = start_cluster(Cluster),
-        [join_cluster(Spec) || Spec <- Cluster],
         assert_config_load_done(Nodes),
 
         %% 2. Stop each in order.
-        lists:foreach(fun stop_slave/1, Nodes),
+        stop_cluster(Nodes),
 
         %% 3. Restart nodes in the same order.  This should not
         %% crash and eventually all nodes should be ready.
@@ -50,7 +51,7 @@ t_copy_conf_override_on_restarts(_Config) ->
 
         ok
     after
-        teardown_cluster(Cluster)
+        stop_cluster(Nodes)
     end.
 
 %%------------------------------------------------------------------------------
@@ -66,157 +67,37 @@ assert_config_load_done(Nodes) ->
         Nodes
     ).
 
+stop_cluster(Nodes) ->
+    [emqx_common_test_helpers:stop_slave(Node) || Node <- Nodes].
+
 start_cluster(Specs) ->
-    [start_slave(I) || I <- Specs].
+    [emqx_common_test_helpers:start_slave(Name, Opts) || {Name, Opts} <- Specs].
 
 start_cluster_async(Specs) ->
     [
         begin
-            spawn_link(fun() -> start_slave(I) end),
+            Opts1 = maps:remove(join_to, Opts),
+            spawn_link(fun() -> emqx_common_test_helpers:start_slave(Name, Opts1) end),
             timer:sleep(7_000)
         end
-     || I <- Specs
+     || {Name, Opts} <- Specs
     ].
 
 cluster(Specs) ->
-    cluster(Specs, []).
+    Env = [
-
+        {emqx, init_config_load_done, false},
-cluster(Specs0, CommonEnv) ->
+        {emqx, boot_modules, []}
-    Specs1 = lists:zip(Specs0, lists:seq(1, length(Specs0))),
+    ],
-    Specs = expand_node_specs(Specs1, CommonEnv),
+    emqx_common_test_helpers:emqx_cluster(Specs, [
-    CoreNodes = [node_id(Name) || {{core, Name, _}, _} <- Specs],
+        {env, Env},
-    %% Assign grpc ports:
+        {apps, [emqx_conf]},
-    BaseGenRpcPort = 9000,
+        {load_schema, false},
-    GenRpcPorts = maps:from_list([
+        {join_to, false},
-        {node_id(Name), {tcp, BaseGenRpcPort + Num}}
+        {env_handler, fun
-     || {{_, Name, _}, Num} <- Specs
+            (emqx) ->
-    ]),
+                application:set_env(emqx, boot_modules, []),
-    %% Set the default node of the cluster:
+                ok;
-    JoinTo =
+            (_) ->
-        case CoreNodes of
+                ok
-            [First | _] -> #{join_to => First};
+        end}
-            _ -> #{}
+    ]).
-        end,
-    [
-        JoinTo#{
-            name => Name,
-            node => node_id(Name),
-            env => [
-                {mria, core_nodes, CoreNodes},
-                {mria, node_role, Role},
-                {gen_rpc, tcp_server_port, BaseGenRpcPort + Number},
-                {gen_rpc, client_config_per_node, {internal, GenRpcPorts}}
-                | Env
-            ],
-            number => Number,
-            role => Role
-        }
-     || {{Role, Name, Env}, Number} <- Specs
-    ].
-
-start_apps(Node) ->
-    Handler = fun
-        (emqx) ->
-            application:set_env(emqx, boot_modules, []),
-            ok;
-        (_) ->
-            ok
-    end,
-    {Node, ok} =
-        {Node, rpc:call(Node, emqx_common_test_helpers, start_apps, [[emqx_conf], Handler])},
-    ok.
-
-stop_apps(Node) ->
-    ok = rpc:call(Node, emqx_common_test_helpers, stop_apps, [[emqx_conf]]).
-
-join_cluster(#{node := Node, join_to := JoinTo}) ->
-    case rpc:call(Node, ekka, join, [JoinTo]) of
-        ok -> ok;
-        ignore -> ok;
-        Err -> error({failed_to_join_cluster, #{node => Node, error => Err}})
-    end.
-
-start_slave(#{node := Node, env := Env}) ->
-    %% We want VMs to only occupy a single core
-    CommonBeamOpts =
-        "+S 1:1 " ++
-            %% redirect logs to the master test node
-            " -master " ++ atom_to_list(node()) ++ " ",
-    %% We use `ct_slave' instead of `slave' because, in
-    %% `t_copy_conf_override_on_restarts', the nodes might be stuck
-    %% some time during boot up, and `slave' has a hard-coded boot
-    %% timeout.
-    {ok, Node} = ct_slave:start(
-        Node,
-        [
-            {erl_flags, CommonBeamOpts ++ ebin_path()},
-            {kill_if_fail, true},
-            {monitor_master, true},
-            {init_timeout, 30_000},
-            {startup_timeout, 30_000}
-        ]
-    ),
-
-    %% Load apps before setting the enviroment variables to avoid
-    %% overriding the environment during app start:
-    [rpc:call(Node, application, load, [App]) || App <- [gen_rpc]],
-    %% Disable gen_rpc listener by default:
-    Env1 = [{gen_rpc, tcp_server_port, false} | Env],
-    setenv(Node, Env1),
-    ok = start_apps(Node),
-    Node.
-
-expand_node_specs(Specs, CommonEnv) ->
-    lists:map(
-        fun({Spec, Num}) ->
-            {
-                case Spec of
-                    core ->
-                        {core, gen_node_name(Num), CommonEnv};
-                    replicant ->
-                        {replicant, gen_node_name(Num), CommonEnv};
-                    {Role, Name} when is_atom(Name) ->
-                        {Role, Name, CommonEnv};
-                    {Role, Env} when is_list(Env) ->
-                        {Role, gen_node_name(Num), CommonEnv ++ Env};
-                    {Role, Name, Env} ->
-                        {Role, Name, CommonEnv ++ Env}
-                end,
-                Num
-            }
-        end,
-        Specs
-    ).
-
-setenv(Node, Env) ->
-    [rpc:call(Node, application, set_env, [App, Key, Val]) || {App, Key, Val} <- Env].
-
-teardown_cluster(Specs) ->
-    Nodes = [I || #{node := I} <- Specs],
-    [rpc:call(I, emqx_common_test_helpers, stop_apps, [emqx_conf]) || I <- Nodes],
-    [stop_slave(I) || I <- Nodes],
-    ok.
-
-stop_slave(Node) ->
-    ct_slave:stop(Node).
-
-host() ->
-    [_, Host] = string:tokens(atom_to_list(node()), "@"),
-    Host.
-
-node_id(Name) ->
-    list_to_atom(lists:concat([Name, "@", host()])).
-
-gen_node_name(N) ->
-    list_to_atom("n" ++ integer_to_list(N)).
-
-ebin_path() ->
-    string:join(["-pa" | paths()], " ").
-
-paths() ->
-    [
-        Path
-     || Path <- code:get_path(),
-        string:prefix(Path, code:lib_dir()) =:= nomatch,
-        string:str(Path, "_build/default/plugins") =:= 0
-    ].

apps/emqx_modules/test/emqx_telemetry_SUITE.erl

@@ -33,6 +33,7 @@
 all() -> emqx_common_test_helpers:all(?MODULE).
 
 init_per_suite(Config) ->
+    net_kernel:start(['master@127.0.0.1', longnames]),
     ok = meck:new(emqx_authz, [non_strict, passthrough, no_history, no_link]),
     meck:expect(
         emqx_authz,
@@ -159,7 +160,6 @@ init_per_testcase(t_exhook_info, Config) ->
     Config;
 init_per_testcase(t_cluster_uuid, Config) ->
     Node = start_slave(n1),
-    ok = setup_slave(Node),
     [{n1, Node} | Config];
 init_per_testcase(t_uuid_restored_from_file, Config) ->
     mock_httpc(),
@@ -184,7 +184,6 @@ init_per_testcase(t_uuid_restored_from_file, Config) ->
         fun set_special_configs/1
     ),
     Node = start_slave(n1),
-    ok = setup_slave(Node),
     [
         {n1, Node},
         {node_uuid, NodeUUID},
@@ -801,12 +800,6 @@ set_special_configs(emqx_authz) ->
 set_special_configs(_App) ->
     ok.
 
-start_slave(Name) ->
-    % We want VMs to only occupy a single core
-    CommonBeamOpts = "+S 1:1 ",
-    {ok, Node} = slave:start_link(host(), Name, CommonBeamOpts ++ ebin_path()),
-    Node.
-
 %% for some unknown reason, gen_rpc running locally or in CI might
 %% start with different `port_discovery' modes, which means that'll
 %% either be listening at the port in the config (`tcp_server_port',
@@ -822,57 +815,41 @@ find_gen_rpc_port() ->
     {ok, {_, Port}} = inet:sockname(EPort),
     Port.
 
-setup_slave(Node) ->
+start_slave(Name) ->
-    TestNode = node(),
     Port = find_gen_rpc_port(),
-    [ok = rpc:call(Node, application, load, [App]) || App <- [gen_rpc, emqx]],
+    TestNode = node(),
-    ok = rpc:call(
-        Node,
-        application,
-        set_env,
-        [gen_rpc, tcp_server_port, 9002]
-    ),
-    ok = rpc:call(
-        Node,
-        application,
-        set_env,
-        [gen_rpc, client_config_per_node, {internal, #{TestNode => Port}}]
-    ),
-    ok = rpc:call(
-        Node,
-        application,
-        set_env,
-        [gen_rpc, port_discovery, manual]
-    ),
     Handler =
         fun
             (emqx) ->
-                application:set_env(
+                application:set_env(emqx, boot_modules, []),
-                    emqx,
-                    boot_modules,
-                    []
-                ),
                 ekka:join(TestNode),
+                emqx_common_test_helpers:load_config(
+                    emqx_modules_schema, ?BASE_CONF, #{raw_with_default => true}
+                ),
+
                 ok;
-            (_) ->
+            (_App) ->
+                emqx_common_test_helpers:load_config(
+                    emqx_modules_schema, ?BASE_CONF, #{raw_with_default => true}
+                ),
                 ok
         end,
-    ok = rpc:call(
+    Opts = #{
-        Node,
+        env => [
-        emqx_common_test_helpers,
+            {gen_rpc, tcp_server_port, 9002},
-        load_config,
+            {gen_rpc, port_discovery, manual},
-        [emqx_modules_schema, ?BASE_CONF, #{raw_with_default => true}]
+            {gen_rpc, client_config_per_node, {internal, #{TestNode => Port}}}
-    ),
+        ],
-    ok = rpc:call(
+
-        Node,
+        load_schema => false,
-        emqx_common_test_helpers,
+        configure_gen_rpc => false,
-        start_apps,
+        env_handler => Handler,
-        [
+        load_apps => [gen_rpc, emqx],
-            [emqx_conf, emqx_modules],
+        listener_ports => [],
-            Handler
+        apps => [emqx_conf, emqx_modules]
-        ]
+    },
-    ),
+
-    ok.
+    emqx_common_test_helpers:start_slave(Name, Opts).
 
 stop_slave(Node) ->
     % This line don't work!!
@@ -892,18 +869,3 @@ leave_cluster() ->
             application:set_env(mria, db_backend, mnesia),
             ekka:leave()
     end.
-
-host() ->
-    [_, Host] = string:tokens(atom_to_list(node()), "@"),
-    Host.
-
-ebin_path() ->
-    string:join(["-pa" | paths()], " ").
-
-paths() ->
-    [
-        Path
-     || Path <- code:get_path(),
-        string:prefix(Path, code:lib_dir()) =:= nomatch,
-        string:str(Path, "_build/default/plugins") =:= 0
-    ].