Hi, I'm writing an mysql backend plugin.
I had stored the user subscribed topic list in mysql. I want to resubscribe the topic while reconnecting.
And how can I send offline message back to client while reconnecting.
Can any body have any information about it.
Thanks very much.

How would you access a value configured using config.hocon? Would be nice if the sample code had at least a simple example of how to use a single variable configured with hocon.

Hi, I am trying to test the compile flow, according to instructions from the doc: https://www.emqx.io/docs/zh/v5.0/extensions/plugins.html#_2-%E6%B5%8B%E8%AF%95%E7%BC%96%E8%AF%91%E7%8E%AF%E5%A2%83

Well, I just clone the repo and run make rel.
Unfortunately, I got the following error info

root@3210f365cfae:/home/emqx/emqx-plugin-template# make rel
/home/emqx/emqx-plugin-template/rebar3 emqx_plugrel tar
===> Verifying dependencies...
+ mkdir -p _build/cmake
+ cd _build/cmake
+ type cmake3
+ CMAKE=cmake
+ cmake -DWITH_BUNDLE_LZ4=ON -DWITH_BUNDLE_SNAPPY=ON ../../c_src
-- The C compiler identification is GNU 10.2.1
-- The CXX compiler identification is GNU 10.2.1
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- LZ4 library: /home/emqx/emqx-plugin-template/_build/default/lib/rocksdb/_build/cmake/lz4/lib/liblz4.a
-- LZ4 includes: /home/emqx/emqx-plugin-template/_build/default/lib/rocksdb/_build/cmake/lz4/include
-- Snappy library: /home/emqx/emqx-plugin-template/_build/default/lib/rocksdb/_build/cmake/snappy/lib/libsnappy.a
-- Snappy includes: /home/emqx/emqx-plugin-template/_build/default/lib/rocksdb/_build/cmake/snappy/include
-- cmake args -DCMAKE_POSITION_INDEPENDENT_CODE=ON;-DCMAKE_CXX_COMPILER=/usr/bin/c++;-DCMAKE_AR=/usr/bin/ar;-DCMAKE_BUILD_TYPE=Rel
ease;-DFAIL_ON_WARNINGS=OFF;-DPORTABLE=ON;-DUSE_RTTI=1;-DWITH_TOOLS=OFF;-DWITH_TESTS=OFF;-DWITH_GFLAGS=OFF;-DWITH_JEMALLOC=OFF;-DW
ITH_TBB=;-DWITH_SNAPPY=TRUE;-DWITH_LZ4=TRUE;-DWITH_ZLIB=;-DWITH_BZ2=;-DWITH_ZSTD=;-Dsnappy_ROOT_DIR=/home/emqx/emqx-plugin-templat
e/_build/default/lib/rocksdb/_build/cmake/snappy;-Dlz4_ROOT_DIR=/home/emqx/emqx-plugin-template/_build/default/lib/rocksdb/_build/
cmake/lz4
-- Found RocksDB library: /home/emqx/emqx-plugin-template/_build/default/lib/rocksdb/_build/cmake/rocksdb-prefix/src/rocksdb-build
/librocksdb.a
-- Found RocksDB includes: /home/emqx/emqx-plugin-template/_build/default/lib/rocksdb/c_src/../deps/rocksdb/include
-- Using OTP lib: /home/erlang/lib/erlang/lib - found
-- Using erl_interface version: erl_interface-5.4
-- Using erts version: erts-14.0
-- Performing Test HAVE_OMIT_LEAF_FRAME_POINTER
-- Performing Test HAVE_OMIT_LEAF_FRAME_POINTER - Success
-- Configuring done
-- Generating done
-- Build files have been written to: /home/emqx/emqx-plugin-template/_build/default/lib/rocksdb/_build/cmake
+ echo done-do_cmake.
done-do_cmake.
===> Compiling c_src/decoder.c
===> Compiling c_src/encoder.c
===> Compiling c_src/jiffy.c
===> Compiling c_src/termstack.c
===> Compiling c_src/utf8.c
===> Compiling c_src/util.c
===> Compiling c_src/doubles.cc
===> Compiling c_src/objects.cc
===> Compiling c_src/double-conversion/bignum-dtoa.cc
===> Compiling c_src/double-conversion/bignum.cc
===> Compiling c_src/double-conversion/cached-powers.cc
===> Compiling c_src/double-conversion/diy-fp.cc
===> Compiling c_src/double-conversion/double-conversion.cc
===> Compiling c_src/double-conversion/fast-dtoa.cc
===> Compiling c_src/double-conversion/fixed-dtoa.cc
===> Compiling c_src/double-conversion/strtod.cc
===> Linking /home/emqx/emqx-plugin-template/_build/default/lib/jiffy/priv/jiffy.so
===> Compiling c_src/async_queue.c
===> Compiling c_src/bcrypt.c
===> Compiling c_src/bcrypt_nif.c
===> Compiling c_src/blowfish.c
===> Linking /home/emqx/emqx-plugin-template/_build/default/lib/bcrypt/priv/bcrypt_nif.so
===> Analyzing applications...
===> Compiling rocksdb
===> Compiling recon
===> Compiling sext
===> Compiling snabbkaffe
===> Compiling lc
===> Compiling cowlib
===> Compiling _build/default/lib/cowlib/src/cow_sse.erl failed
_build/default/lib/cowlib/src/cow_sse.erl:56:29: type variable 'State' is only used once (is unbound)

make: *** [Makefile:49: rel] Error 1

Have no idea what does this mean, and how to fix the error? Any suggestions will be appreciated!

Hi, I want to install plugin in windows. I occured error.
gksrb@PASSTECH-HANGYU MINGW64 /d/download/emqx-plugin-template-master $ make rel C:/ProgramData/chocolatey/lib/make/tools/install/bin/make.exe get-rebar3 make[1]: Entering directory 'D:/download/emqx-plugin-template-master' make[1]: Leaving directory 'D:/download/emqx-plugin-template-master' /c/Erlang/bin/rebar3 emqx_plugrel tar ===> Fetching emqx_plugrel (from {git,"https://github.com/emqx/emqx_plugrel.git", {tag,"0.3.0"}}) ===> Fetching jsx v3.1.0 ===> Analyzing applications... ===> Compiling jsx ===> Compiling emqx_plugrel ===> Verifying dependencies... ===> Fetching emqx (from {git_subdir,"https://github.com/emqx/emqx.git", {tag,"v5.0.25"}, "apps/emqx"}) ===> Fetching rebar3_proper v0.12.1 ===> Analyzing applications... ===> Compiling rebar3_proper ===> Fetching rebar3_path_deps v0.4.0 ===> Analyzing applications... ===> Compiling rebar3_path_deps ===> Fetching emqx_utils (from {git_subdir,"https://github.com/emqx/emqx.git", {tag,"v5.0.25"}, "apps/emqx_utils"}) ===> Fetching map_sets v1.1.0 ===> Fetching cowboy (from {git,"https://github.com/emqx/cowboy",{tag,"2.9.0"}}) ===> Fetching ekka (from {git,"https://github.com/emqx/ekka",{tag,"0.15.1"}}) ===> Fetching emqx_http_lib (from {git,"https://github.com/emqx/emqx_http_lib.git", {tag,"0.5.2"}}) ===> Skipping emqx_utils (from {path,"../emqx_utils"}) as an app of the same name has already been fetched ===> Fetching esockd (from {git,"https://github.com/emqx/esockd",{tag,"5.9.6"}}) ===> Fetching gen_rpc (from {git,"https://github.com/emqx/gen_rpc",{tag,"2.8.1"}}) ===> Fetching rebar3_hex v7.0.6 ===> Fetching hex_core v0.8.4 ===> Fetching verl v1.1.1 ===> Analyzing applications... ===> Compiling hex_core ===> Compiling verl ===> Compiling rebar3_hex ===> Fetching gproc (from {git,"https://github.com/uwiger/gproc",{tag,"0.8.0"}}) ===> Fetching hocon (from {git,"https://github.com/emqx/hocon.git",{tag,"0.39.4"}}) ===> Fetching jiffy (from {git,"https://github.com/emqx/jiffy",{tag,"1.0.5"}}) ===> Fetching pc (from {git,"https://github.com/emqx/port_compiler.git",{tag,"v1.11.1"}}) ===> Analyzing applications... ===> Compiling pc ===> Fetching lc (from {git,"https://github.com/emqx/lc.git",{tag,"0.3.2"}}) ===> Fetching pbkdf2 (from {git,"https://github.com/emqx/erlang-pbkdf2.git",{tag,"2.0.4"}}) ===> Fetching recon (from {git,"https://github.com/ferd/recon",{tag,"2.5.1"}}) ===> Fetching snabbkaffe (from {git,"https://github.com/kafka4beam/snabbkaffe.git", {tag,"1.0.8"}}) ===> Fetching cowlib (from {git,"https://github.com/ninenines/cowlib",{tag,"2.8.0"}}) ===> Fetching eetcd (from {git,"https://github.com/zhongwencool/eetcd",{tag,"v0.3.4"}}) ===> Fetching rebar3_gpb_plugin v2.13.1 ===> Fetching gpb v4.11.1 ===> Analyzing applications... ===> Compiling gpb ===> Compiling rebar3_gpb_plugin Compiling descriptor.proto... Compiling gpb_descriptor.erl... Compiling gpb_compile_descr.erl... ===> Fetching rebar3_eetcd_plugin v0.3.0 ===> Fetching providers v1.8.1 ===> Fetching getopt v1.0.1 ===> Analyzing applications... ===> Compiling getopt ===> Compiling providers ===> Compiling gpb ===> Compiling rebar3_eetcd_plugin ===> Fetching getopt v1.0.1 ===> Fetching mria (from {git,"https://github.com/emqx/mria",{tag,"0.5.2"}}) ===> Fetching ranch (from {git,"https://github.com/ninenines/ranch",{tag,"1.8.0"}}) ===> Skipping snabbkaffe (from {git,"https://github.com/kafka4beam/snabbkaffe", {tag,"1.0.0"}}) as an app of the same name has already been fetched ===> Skipping snabbkaffe (from {git,"https://github.com/kafka4beam/snabbkaffe", {tag,"0.17.1"}}) as an app of the same name has already been fetched ===> Skipping snabbkaffe v1.0.1 as an app of the same name has already been fetched ===> Fetching typerefl (from {git,"https://github.com/k32/typerefl.git",{tag,"0.9.0"}}) ===> Skipping typerefl (from {git,"https://github.com/ieQu1/typerefl.git",{tag,"0.9.1"}}) as an app of the same name has already been fetched ===> Skipping gen_rpc (from {git,"https://github.com/emqx/gen_rpc",{tag,"3.0.1"}}) as an app of the same name has already been fetched ===> Fetching gun v1.3.3 ===> Fetching mnesia_rocksdb (from {git,"https://github.com/emqx/mnesia_rocksdb", {tag,"0.1.12"}}) ===> Fetching optvar (from {git,"https://github.com/emqx/optvar",{tag,"1.0.4"}}) ===> Fetching replayq (from {git,"https://github.com/emqx/replayq",{tag,"0.3.6"}}) ===> Fetching coveralls v2.2.0 ===> Analyzing applications... ===> Compiling coveralls ===> Skipping snabbkaffe (from {git,"https://github.com/kafka4beam/snabbkaffe", {tag,"1.0.7"}}) as an app of the same name has already been fetched ===> Skipping cowlib v2.7.3 as an app of the same name has already been fetched ===> Fetching rocksdb (from {git,"https://github.com/emqx/erlang-rocksdb.git", {tag,"1.7.2-emqx-9"}}) ===> Fetching sext v1.8.0 -- Building for: Visual Studio 17 2022 -- The C compiler identification is MSVC 19.32.31329.0 -- The CXX compiler identification is MSVC 19.32.31329.0 -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Check for working C compiler: C:/Program Files/Microsoft Visual Studio/2022/Community/VC/Tools/MSVC/14.32.31326/bin/Hostx64/x64/cl.exe - skipped -- Detecting C compile features -- Detecting C compile features - done -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Check for working CXX compiler: C:/Program Files/Microsoft Visual Studio/2022/Community/VC/Tools/MSVC/14.32.31326/bin/Hostx64/x64/cl.exe - skipped -- Detecting CXX compile features -- Detecting CXX compile features - done -- LZ4 library: D:/download/emqx-plugin-template-master/_build/default/lib/rocksdb/_build/cmake/lz4/lib/lz4.lib -- LZ4 includes: D:/download/emqx-plugin-template-master/_build/default/lib/rocksdb/_build/cmake/lz4/include -- Snappy library: D:/download/emqx-plugin-template-master/_build/default/lib/rocksdb/_build/cmake/snappy/lib/snappy.lib -- Snappy includes: D:/download/emqx-plugin-template-master/_build/default/lib/rocksdb/_build/cmake/snappy/include -- cmake args -DCMAKE_POSITION_INDEPENDENT_CODE=ON;-DCMAKE_CXX_COMPILER=C:/Program Files/Microsoft Visual Studio/2022/Community/VC/Tools/MSVC/14.32.31326/bin/Hostx64/x64/cl.exe;-DCMAKE_AR=C:/Program Files/Microsoft Visual Studio/2022/Community/VC/Tools/MSVC/14.32.31326/bin/Hostx64/x64/lib.exe;-DCMAKE_BUILD_TYPE=Release;-DFAIL_ON_WARNINGS=OFF;-DPORTABLE=ON;-DUSE_RTTI=1;-DWITH_TOOLS=OFF;-DWITH_TESTS=OFF;-DWITH_GFLAGS=OFF;-DWITH_JEMALLOC=OFF;-DWITH_TBB=;-DWITH_SNAPPY=TRUE;-DWITH_LZ4=TRUE;-DWITH_ZLIB=;-DWITH_BZ2=;-DWITH_ZSTD=;-DWITHOUT_THIRDPARTY_INC=ON;-Dsnappy_ROOT_DIR=D:/download/emqx-plugin-template-master/_build/default/lib/rocksdb/_build/cmake/snappy;-Dlz4_ROOT_DIR=D:/download/emqx-plugin-template-master/_build/default/lib/rocksdb/_build/cmake/lz4 -- Found RocksDB library: D:/download/emqx-plugin-template-master/_build/default/lib/rocksdb/_build/cmake/rocksdb-prefix/src/rocksdb-build/Release/rocksdb.lib -- Found RocksDB includes: D:/download/emqx-plugin-template-master/_build/default/lib/rocksdb/c_src/../deps/rocksdb/include -- Using OTP lib: c:/Erlang/lib - found -- Using erl_interface version: erl_interface-5.4 -- Using erts version: erts-14.0.1 -- Configuring done -- Generating done -- Build files have been written to: D:/download/emqx-plugin-template-master/_build/default/lib/rocksdb/_build/cmake ===> Compiling d:/download/emqx-plugin-template-master/c_src/decoder.c ===> Uncaught error in rebar_core. Run with DIAGNOSTIC=1 to see stacktrace or consult rebar3.crashdump ===> When submitting a bug report, please include the output of 'rebar3 report "your command"' make: *** [Makefile:49: rel] Error 1

rebar3.crashdump
Error: badarg [{re,replace, [[77,105,99,114,111,115,111,102,116,32,40,82,41,32,67,47,67,43,43,32, 52572,51201,54868,32,52980,54028,51068,47084,32,48260,51204,32,49,57, 46,51,50,46,51,49,51,50,57,40,120,54,52,41,10,67,111,112,121,114,105, 103,104,116,32,40,99,41,32,77,105,99,114,111,115,111,102,116,32,67,111, 114,112,111,114,97,116,105,111,110,46,32,65,108,108,32,114,105,103,104, 116,115,32,114,101,115,101,114,118,101,100,46,10,10,100,101,99,111,100, 101,114,46,99,10,99,95,115,114,99,47,100,101,99,111,100,101,114,46,99, 40,52,41,58,32,102,97,116,97,108,32,101,114,114,111,114,32,67,49,48,56, 51,58,32,54252,54632,32,54028,51068,51012,32,50676,32,49688,32,50630, 49845,45768,45796,46,32,39,97,115,115,101,114,116,46,104,39,58,32,78, 111,32,115,117,99,104,32,102,105,108,101,32,111,114,32,100,105,114,101, 99,116,111,114,121,10], "c_src/decoder.c", "d:/download/emqx-plugin-template-master/c_src/decoder.c", [{return,list},global]], [{file,"re.erl"},{line,987},{error_info,#{module => erl_stdlib_errors}}]}, {pc_compilation,exec_compiler,4, [{file,"d:/download/emqx-plugin-template-master/_build/default/plugins/pc/src/pc_compilation.erl"}, {line,197}]}, {pc_compilation,compile_each,5, [{file,"d:/download/emqx-plugin-template-master/_build/default/plugins/pc/src/pc_compilation.erl"}, {line,135}]}, {pc_compilation,'-compile_sources/2-lists^foldl/2-0-',3, [{file,"d:/download/emqx-plugin-template-master/_build/default/plugins/pc/src/pc_compilation.erl"}, {line,96}]}, {pc_compilation,compile_sources,2, [{file,"d:/download/emqx-plugin-template-master/_build/default/plugins/pc/src/pc_compilation.erl"}, {line,96}]}, {pc_compilation,compile_and_link,2, [{file,"d:/download/emqx-plugin-template-master/_build/default/plugins/pc/src/pc_compilation.erl"}, {line,42}]}, {pc_prv_compile,'-do/1-lc$^0/1-0-',2, [{file,"d:/download/emqx-plugin-template-master/_build/default/plugins/pc/src/pc_prv_compile.erl"}, {line,53}]}, {pc_prv_compile,do,1, [{file,"d:/download/emqx-plugin-template-master/_build/default/plugins/pc/src/pc_prv_compile.erl"}, {line,54}]}]

$ rebar3 --version rebar 3.22.0 on Erlang/OTP 26 Erts 14.0.1

erlang version is otp_win64_26.0.1

How can I fix this?

I have enabled the emqttd_plugin_template in the broker but how would I get the metrics from a broker as described in plugins description.

Description of plugin is-

The plugin could register callbacks for hooks. The hooks will be run by the broker when a client connected/disconnected, a topic subscribed/unsubscribed or a message published/delivered:

client.connected Run when a client connected to the broker successfully
client.subscribe Run before a client subscribes topics
client.subscribe.after Run after a client subscribed topics
client.unsubscribe Run when a client unsubscribes topics
message.publish Run when a message is published
message.delivered Run when a message is delivered
message.acked Run when a message(qos1/2) is acked
client.disconnected Run when a client is disconnnected

Problem - According to the description, I am unable to get the metrics information from a broker like when the client connected , client disconnected, message published, message delivered and message acknowledged.

So I am using an Ubuntu 16.04 on AWS with EMQX 3.1, trying to post MQTT messages to my Dreamfactory mySQL. I am following this tutorial: Learn, How to save MQTT messages into a MySQL Database, which runs on EMQ 2.3.5. So far the only thing you had to modify there was this code on:

ubuntu@ip-172-31-19-97:~/emqx-rel/deps/emqx_plugin_template/src$ nano emqx_plugin_template.erl

%% Transform message and return
on_message_publish(Message = #message{topic = <<"$SYS/", _/binary>>}, _Env) ->
    {ok, Message};

on_message_publish(Message, _Env) ->

    io:format("publish ~s~n", [emqttd_message:format(Message)]),
    MessageBin = element(12, Message),
    MessageStr = binary_to_list(MessageBin),inets:start(),
    Method = post,URL = "http://127.0.0.1/api/v2/mysql/_table/log",
    Header = [{"X-DreamFactory-Api-Key", "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"}],
    Type = "application/json",Body = MessageStr,HTTPOptions = [],
    Options = [],
    R = httpc:request(Method, {URL, Header, Type, Body}, HTTPOptions, Options),

    {ok, Message}.

I am wondering if there is anything that I need to change in order to make in work in EMQX 3.1.

I have tried changing the emqtt_message:format to emqx_message:format following the full code structure but it didn't work.

Greetings. Are there end-to-end instructions on creating, building and deploying an EMQ plug-in for those with no prior experience with Erlang OTP? There is a link but it's a circular reference back to this repository:

https://docs.emqx.io/broker/v3.0/en/plugins.html#plugin-development-template

I'm seeking to use EMQ for experimental Erlang development with MQTT as you would the Cowboy HTTP server for example.

Please advise, thanks!

Links to Plugin Development guide, etc. are all broken.

Im not sure how you get any configuration data into the plugin as its quite different from any of the other included plugins. How do we access it?

Also there is no priv folder with a schema file in it

Cheers

I'd like to develop my own plugin that performs custom actions, and am not entirely sure how to go about it... When can we have a plugin development guide ready?

What I'd like to know:

• Plugins rely on -include_lib("emqx/include/emqx.hrl"). What is the procedure of developing outside outside EMQX
• After compilation, where does one put the files or are they started as a normal Erlang process that can run outside EMQX? See Plugin is a normal Erlang application that can be started/stopped dynamically by a running EMQ broker.

I try emqx-plugin-template v3.0.0 in emqx 3.0.0, if open emqx-plugin-template plugin,any username and password will auth success, which version fix this problem

Could tell me which version fixed this issue? This record is not found in the updated log and issues

Hi,

I am following the documentation to compile emqx with the template plugin:

export EMQX_EXTRA_PLUGINS=emqx_plugin_template
make

Output/Error:

===> Verifying dependencies...
===> Fetching emqx_plugin_template (from {git,"https://github.com/emqx/emqx-plugin-template",
                                {tag,"4.3.0"}})
===> Compiling emqx_plugin_template
===> Compiling _build/default/lib/emqx_plugin_template/src/emqx_plugin_template.erl failed
emqx_plugin_template.erl:19: can't find include file "emqx.hrl"

emqx_plugin_template.erl:145: record message undefined
emqx_plugin_template.erl:152: record message undefined

make: *** [Makefile:78: emqx] Error 1                                

PS. I know this is community supported but I am an erlang newbie to contribute a fix here.

This is my config.hocon file
{
"topic" = "mqtt_presence",
"port" = 9092
}

How do i can get them to emqx-plugin-messenger.erl to use as define variables