feat(message transformation): add timestamp and pub_props fields to read context

Fixes https://emqx.atlassian.net/browse/EMQX-12684

Fixes https://emqx.atlassian.net/browse/EMQX-12678

apps/emqx_message_transformation/src/emqx_message_transformation.erl

@@ -62,9 +62,11 @@
     node := _,
     payload := _,
     peername := _,
+    pub_props := _,
     publish_received_at := _,
     qos := _,
     retain := _,
+    timestamp := _,
     topic := _,
     user_property := _,
     username := _,
@@ -345,6 +347,7 @@ message_to_context(#message{} = Message, Payload, Transformation) ->
                 undefined
         end,
     Username = maps:get(username, Headers, undefined),
+    Timestamp = erlang:system_time(millisecond),
     #{
         dirty => Dirty,
 
@@ -355,9 +358,11 @@ message_to_context(#message{} = Message, Payload, Transformation) ->
         node => node(),
         payload => Payload,
         peername => Peername,
+        pub_props => Props,
         publish_received_at => Message#message.timestamp,
         qos => Message#message.qos,
         retain => emqx_message:get_flag(retain, Message, false),
+        timestamp => Timestamp,
         topic => Message#message.topic,
         user_property => UserProperties,
         username => Username

apps/emqx_message_transformation/test/emqx_message_transformation_http_api_SUITE.erl

@@ -504,7 +504,7 @@ assert_monitor_metrics() ->
         receive
             PATTERN = ____Msg0 -> ____Msg0
         after TIMEOUT ->
-            error({message_not_received, ?LINE})
+            error({message_not_received, {line, ?LINE}})
         end
     end)()
 ).
@@ -608,6 +608,8 @@ t_smoke_test(_Config) ->
 %%   * peername
 %%   * publish_received_at
 %%   * username
+%%   * timestamp
+%%   * pub_props (and specific fields within containing hyphens)
 t_smoke_test_2(_Config) ->
     Name1 = <<"foo">>,
     Operations = [
@@ -617,14 +619,22 @@ t_smoke_test_2(_Config) ->
         operation(<<"payload.peername">>, <<"peername">>),
         operation(<<"payload.publish_received_at">>, <<"publish_received_at">>),
         operation(<<"payload.username">>, <<"username">>),
-        operation(<<"payload.flags">>, <<"flags">>)
+        operation(<<"payload.flags">>, <<"flags">>),
+        operation(<<"payload.timestamp">>, <<"timestamp">>),
+        operation(<<"payload.pub_props">>, <<"pub_props">>),
+        operation(<<"payload.content_type">>, <<"pub_props.Content-Type">>)
     ],
     Transformation1 = transformation(Name1, Operations),
     {201, _} = insert(Transformation1),
     ClientId = atom_to_binary(?FUNCTION_NAME),
     C1 = connect(ClientId),
     {ok, _, [_]} = emqtt:subscribe(C1, <<"t/#">>, [{qos, 2}]),
-    ok = publish(C1, <<"t/1">>, #{}),
+    ok = publish(C1, <<"t/1">>, #{}, _QoS = 0, #{
+        props => #{
+            'Content-Type' => <<"application/json">>,
+            'User-Property' => [{<<"a">>, <<"b">>}]
+        }
+    }),
     {publish, #{payload := Payload0}} = ?assertReceiveReturn({publish, _}, 1_000),
     NodeBin = atom_to_binary(node()),
     ?assertMatch(
@@ -635,7 +645,13 @@ t_smoke_test_2(_Config) ->
             <<"peername">> := <<"127.0.0.1:", _/binary>>,
             <<"publish_received_at">> := PRAt,
             <<"username">> := <<"undefined">>,
-            <<"flags">> := #{<<"dup">> := false, <<"retain">> := false}
+            <<"flags">> := #{<<"dup">> := false, <<"retain">> := false},
+            <<"timestamp">> := _,
+            <<"pub_props">> := #{
+                <<"Content-Type">> := <<"application/json">>,
+                <<"User-Property">> := #{<<"a">> := <<"b">>}
+            },
+            <<"content_type">> := <<"application/json">>
         } when is_integer(PRAt),
         emqx_utils_json:decode(Payload0, [return_maps])
     ),
@@ -644,7 +660,12 @@ t_smoke_test_2(_Config) ->
     Username = <<"myusername">>,
     C2 = connect(ClientId, _IsPersistent = false, #{start_props => #{username => Username}}),
     {ok, _, [_]} = emqtt:subscribe(C2, <<"t/#">>, [{qos, 2}]),
-    ok = publish(C2, <<"t/1">>, #{}),
+    ok = publish(C2, <<"t/1">>, #{}, _QoS = 0, #{
+        props => #{
+            'Content-Type' => <<"application/json">>,
+            'User-Property' => [{<<"a">>, <<"b">>}]
+        }
+    }),
     {publish, #{payload := Payload1}} = ?assertReceiveReturn({publish, _}, 1_000),
     ?assertMatch(
         #{
@@ -654,7 +675,13 @@ t_smoke_test_2(_Config) ->
             <<"peername">> := <<"127.0.0.1:", _/binary>>,
             <<"publish_received_at">> := PRAt,
             <<"username">> := Username,
-            <<"flags">> := #{<<"dup">> := false, <<"retain">> := false}
+            <<"flags">> := #{<<"dup">> := false, <<"retain">> := false},
+            <<"timestamp">> := _,
+            <<"pub_props">> := #{
+                <<"Content-Type">> := <<"application/json">>,
+                <<"User-Property">> := #{<<"a">> := <<"b">>}
+            },
+            <<"content_type">> := <<"application/json">>
         } when is_integer(PRAt),
         emqx_utils_json:decode(Payload1, [return_maps])
     ),