Merge pull request #13172 from zmstone/0603-add-redis-arg-formatter-to-rule-engine-funcs

feat(redis): add a rule function to help formatting redis args

apps/emqx_bridge_redis/src/emqx_bridge_redis_connector.erl

@@ -128,8 +128,8 @@ on_query(
                 #{instance_id => InstId, cmd => Cmd, batch => false, mode => sync, result => Result}
             ),
             Result;
-        Error ->
-            Error
+        {error, Reason} ->
+            {error, Reason}
     end.
 
 on_batch_query(
@@ -165,8 +165,8 @@ on_batch_query(
                 }
             ),
             Result;
-        Error ->
-            Error
+        {error, Reason} ->
+            {error, Reason}
     end.
 
 trace_format_commands(Commands0) ->
@@ -204,11 +204,15 @@ query(InstId, Query, RedisConnSt) ->
     end.
 
 proc_command_template(CommandTemplate, Msg) ->
-    lists:map(
-        fun(ArgTks) ->
-            emqx_placeholder:proc_tmpl(ArgTks, Msg, #{return => full_binary})
-        end,
-        CommandTemplate
+    lists:reverse(
+        lists:foldl(
+            fun(ArgTks, Acc) ->
+                New = proc_tmpl(ArgTks, Msg),
+                lists:reverse(New, Acc)
+            end,
+            [],
+            CommandTemplate
+        )
     ).
 
 preproc_command_template(CommandTemplate) ->
@@ -216,3 +220,18 @@ preproc_command_template(CommandTemplate) ->
         fun emqx_placeholder:preproc_tmpl/1,
         CommandTemplate
     ).
+
+%% This function mimics emqx_placeholder:proc_tmpl/3 but with an
+%% injected special handling of map_to_redis_hset_args result
+%% which is a list of redis command args (all in binary string format)
+proc_tmpl([{var, Phld}], Data) ->
+    case emqx_placeholder:lookup_var(Phld, Data) of
+        [map_to_redis_hset_args | L] ->
+            L;
+        Other ->
+            [emqx_utils_conv:bin(Other)]
+    end;
+proc_tmpl(Tokens, Data) ->
+    %% more than just a var ref, but a string, or a concatenation of string and a var
+    %% this is must be a single arg, format it into a binary
+    [emqx_placeholder:proc_tmpl(Tokens, Data, #{return => full_binary})].

apps/emqx_bridge_redis/test/emqx_bridge_v2_redis_SUITE.erl

@@ -46,7 +46,8 @@ matrix_testcases() ->
         t_start_stop,
         t_create_via_http,
         t_on_get_status,
-        t_sync_query
+        t_sync_query,
+        t_map_to_redis_hset_args
     ].
 
 init_per_suite(Config) ->
@@ -133,7 +134,7 @@ common_init_per_testcase(TestCase, Config) ->
     Path = group_path(Config),
     ct:comment(Path),
     ConnectorConfig = connector_config(Name, Path, NConfig),
-    BridgeConfig = action_config(Name, Path, Name),
+    BridgeConfig = action_config(Name, Path, Name, TestCase),
     ok = snabbkaffe:start_trace(),
     [
         {connector_type, ?CONNECTOR_TYPE},
@@ -222,7 +223,14 @@ parse_and_check_connector_config(InnerConfigMap, Name) ->
     ct:pal("parsed config: ~p", [Config]),
     InnerConfigMap.
 
-action_config(Name, Path, ConnectorId) ->
+action_config(Name, Path, ConnectorId, TestCase) ->
+    Template =
+        try
+            ?MODULE:TestCase(command_template)
+        catch
+            _:_ ->
+                [<<"RPUSH">>, <<"MSGS/${topic}">>, <<"${payload}">>]
+        end,
     [RedisType, _Transport | _] = Path,
     CommonCfg =
         #{
@@ -230,7 +238,7 @@ action_config(Name, Path, ConnectorId) ->
             <<"connector">> => ConnectorId,
             <<"parameters">> =>
                 #{
-                    <<"command_template">> => [<<"RPUSH">>, <<"MSGS/${topic}">>, <<"${payload}">>],
+                    <<"command_template">> => Template,
                     <<"redis_type">> => atom_to_binary(RedisType)
                 },
             <<"local_topic">> => <<"t/redis">>,
@@ -262,8 +270,11 @@ parse_and_check_bridge_config(InnerConfigMap, Name) ->
     emqx_bridge_v2_testlib:parse_and_check(?BRIDGE_TYPE_BIN, Name, InnerConfigMap).
 
 make_message() ->
-    ClientId = emqx_guid:to_hexstr(emqx_guid:gen()),
     Payload = emqx_guid:to_hexstr(emqx_guid:gen()),
+    make_message_with_payload(Payload).
+
+make_message_with_payload(Payload) ->
+    ClientId = emqx_guid:to_hexstr(emqx_guid:gen()),
     #{
         clientid => ClientId,
         payload => Payload,
@@ -290,7 +301,7 @@ t_start_stop(matrix) ->
         [sentinel, tcp],
         [cluster, tcp]
     ]};
-t_start_stop(Config) ->
+t_start_stop(Config) when is_list(Config) ->
     emqx_bridge_v2_testlib:t_start_stop(Config, redis_bridge_stopped),
     ok.
 
@@ -300,7 +311,7 @@ t_create_via_http(matrix) ->
         [sentinel, tcp],
         [cluster, tcp]
     ]};
-t_create_via_http(Config) ->
+t_create_via_http(Config) when is_list(Config) ->
     emqx_bridge_v2_testlib:t_create_via_http(Config),
     ok.
 
@@ -310,7 +321,7 @@ t_on_get_status(matrix) ->
         [sentinel, tcp],
         [cluster, tcp]
     ]};
-t_on_get_status(Config) ->
+t_on_get_status(Config) when is_list(Config) ->
     emqx_bridge_v2_testlib:t_on_get_status(Config, #{failure_status => connecting}),
     ok.
 
@@ -320,7 +331,7 @@ t_sync_query(matrix) ->
         [sentinel, tcp],
         [cluster, tcp]
     ]};
-t_sync_query(Config) ->
+t_sync_query(Config) when is_list(Config) ->
     ok = emqx_bridge_v2_testlib:t_sync_query(
         Config,
         fun make_message/0,
@@ -328,3 +339,22 @@ t_sync_query(Config) ->
         redis_bridge_connector_send_done
     ),
     ok.
+
+t_map_to_redis_hset_args(matrix) ->
+    {map_to_redis_hset_args, [
+        [single, tcp],
+        [sentinel, tcp],
+        [cluster, tcp]
+    ]};
+t_map_to_redis_hset_args(command_template) ->
+    [<<"HMSET">>, <<"t_map_to_redis_hset_args">>, <<"${payload}">>];
+t_map_to_redis_hset_args(Config) when is_list(Config) ->
+    Payload = emqx_rule_funcs:map_to_redis_hset_args(#{<<"a">> => 1, <<"b">> => <<"2">>}),
+    MsgFn = fun() -> make_message_with_payload(Payload) end,
+    ok = emqx_bridge_v2_testlib:t_sync_query(
+        Config,
+        MsgFn,
+        fun(Res) -> ?assertMatch({ok, _}, Res) end,
+        redis_bridge_connector_send_done
+    ),
+    ok.

apps/emqx_rule_engine/src/emqx_rule_funcs.erl

@@ -160,6 +160,7 @@
     find/3,
     join_to_string/1,
     join_to_string/2,
+    map_to_redis_hset_args/1,
     join_to_sql_values_string/1,
     jq/2,
     jq/3,
@@ -814,6 +815,38 @@ join_to_string(Str) -> emqx_variform_bif:join_to_string(Str).
 
 join_to_string(Sep, List) -> emqx_variform_bif:join_to_string(Sep, List).
 
+%% @doc Format map key-value pairs as redis HSET (or HMSET) command fields.
+%% Notes:
+%% - Non-string keys in the input map are dropped
+%% - Keys are not quoted
+%% - String values are always quoted
+%% - No escape sequence for keys and values
+%% - Float point values are formatted with fixed (6) decimal point compact-formatting
+map_to_redis_hset_args(Map) when erlang:is_map(Map) ->
+    [map_to_redis_hset_args | maps:fold(fun redis_hset_acc/3, [], Map)].
+
+redis_hset_acc(K, V, IoData) ->
+    try
+        [redis_field_name(K), redis_field_value(V) | IoData]
+    catch
+        _:_ ->
+            IoData
+    end.
+
+redis_field_name(K) when erlang:is_binary(K) ->
+    K;
+redis_field_name(K) ->
+    throw({bad_redis_field_name, K}).
+
+redis_field_value(V) when erlang:is_binary(V) ->
+    V;
+redis_field_value(V) when erlang:is_integer(V) ->
+    integer_to_binary(V);
+redis_field_value(V) when erlang:is_float(V) ->
+    float2str(V, 6);
+redis_field_value(V) when erlang:is_boolean(V) ->
+    atom_to_binary(V).
+
 join_to_sql_values_string(List) ->
     QuotedList =
         [

apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl

@@ -1376,6 +1376,27 @@ t_parse_date_errors(_) ->
 
     ok.
 
+t_map_to_redis_hset_args(_Config) ->
+    Do = fun(Map) -> tl(emqx_rule_funcs:map_to_redis_hset_args(Map)) end,
+    ?assertEqual([], Do(#{})),
+    ?assertEqual([], Do(#{1 => 2})),
+    ?assertEqual([<<"a">>, <<"1">>], Do(#{<<"a">> => 1, 3 => 4})),
+    ?assertEqual([<<"a">>, <<"1.1">>], Do(#{<<"a">> => 1.1})),
+    ?assertEqual([<<"a">>, <<"true">>], Do(#{<<"a">> => true})),
+    ?assertEqual([<<"a">>, <<"false">>], Do(#{<<"a">> => false})),
+    ?assertEqual([<<"a">>, <<"">>], Do(#{<<"a">> => <<"">>})),
+    ?assertEqual([<<"a">>, <<"i j">>], Do(#{<<"a">> => <<"i j">>})),
+    %% no determined ordering
+    ?assert(
+        case Do(#{<<"a">> => 1, <<"b">> => 2}) of
+            [<<"a">>, <<"1">>, <<"b">>, <<"2">>] ->
+                true;
+            [<<"b">>, <<"2">>, <<"a">>, <<"1">>] ->
+                true
+        end
+    ),
+    ok.
+
 %%------------------------------------------------------------------------------
 %% Utility functions
 %%------------------------------------------------------------------------------

apps/emqx_utils/src/emqx_placeholder.erl

@@ -37,7 +37,8 @@
     proc_tmpl_deep/3,
 
     bin/1,
-    sql_data/1
+    sql_data/1,
+    lookup_var/2
 ]).
 
 -export([

apps/emqx_utils/src/emqx_utils.app.src

@@ -2,7 +2,7 @@
 {application, emqx_utils, [
     {description, "Miscellaneous utilities for EMQX apps"},
     % strict semver, bump manually!
-    {vsn, "5.2.0"},
+    {vsn, "5.2.1"},
     {modules, [
         emqx_utils,
         emqx_utils_api,

changes/ee/feat-13172.en.md

@@ -0,0 +1,5 @@
+Added a rule function `map_to_redis_hset_args` to help preparing redis HSET (or HMSET) multi-fields values.
+
+For example, if `payload.value` is a map of multiple data fields,
+this rule `SELECT  map_to_redis_hset_args(payload.value) as hset_fields FROM  "t/#"` can prepare `hset_fields`
+for redis action to render the command template like `HMSET name1 ${hset_fields}`.