webhook generates empty post about emqx-web-hook

[HJianBo]

Hi, @victorclaessen Is your message going to be big? There is a BUG in v4.0.6 that causes a large message not to be encoded as JSON. see emqx/emqx#3382

Please you can try the v4.1-alpha.2 version. It may be fixed it.

[victorclaessen]

In my case, the message payload was short (the string value "test"), so I'm not sure if the bug affects this situation.

Could you possibly comment on my test strategy? Am I doing things right generally?

I will try to get the alpha version. (edit) I have looked at the alpha version of the plugin, but I'm not sure how to compile it. Do you have instructions for compiling, or a binary for Debian 10/amd64?

[victorclaessen]

I'm sorry. My understanding of parsing POST data in PHP was wrong. EMQ is posting all the variables as json. PHP just doesn't get json data like it does HTML form data (as explained here). When I changed my webhook.php to the following, I got my json formatted data:

<?php
$name=$_SERVER[UNIQUE_ID];
file_put_contents("webhooklog/post.$name.log", file_get_contents("php://input"));
print "ok";
?>

The data in the log file was:

{"username":"undefined","topic":"t/test","timestamp":1587891259502,"qos":0,"publish_received_at":1587891259502,"peerh
ost":"127.0.0.1","payload":"TEST","node":"emqx@REDACTEDHOSTNAME","msg":"TEST","id":"5A42DBE76EE02A1
D6490031280001","headers":{"username":"undefined","protocol":"mqtt","proto_ver":4,"peerhost":"127.0.0.1"},"flags":{"r
etain":false,"dup":false},"event":"message.publish","clientid":"mosq-SplOK4c5Z2Fgr1HWCZ"}

I will now go on to try and figure out how to format the json data. I did not find anything about the formatting in the documentation. If I cannot get it to work, I will open a new issue.

Sorry to bother you with this.