Missing request body despite echo_read_request_body use

[jakubgs]

I'm using the echo modules to send the same GitHub webhook request to two backends that needs to receive it. I spit them using echo_subrequest_async, but when I do there is no request body. I have tried using both -b $request_body and -f $request_body_file with the same effect:

location = /webhook {
  echo_read_request_body;
  echo_subrequest_async POST /webhook_backend_0 -f $request_body_file;
  echo_subrequest_async POST /webhook_backend_1 -f $request_body_file;
}
location = /webhook_backend_0 {
  proxy_pass http://10.10.0.10:8080/webhook;
}
location = /webhook_backend_1 {
  proxy_pass http://10.10.0.20:8080/webhook;
}

When using -f $request_body_file I managed to catch this in Nginx errors:

open() "/var/lib/nginx/body/0000005084" failed (2: No such file or directory), client: 1.2.3.4, server: example.org, request: "POST /webhook HTTP/1.1", host: "example.org"

Which indicates that the request body is indeed missing, but as far as I know it is not, since GitHub does send it.

This suggests a bug in the echo module.

[jakubgs]

I have attempted to mitigate this issue by adding echo_sleep 0.001 and echo_blocking_sleep 0.001 in order to force the body to be loaded, and it does appear to slightly decrease the instances of missing body in Webhook request.

[jakubgs]

I'm actually a bit confused as to what's the correct way of doing this. I see at least 6 options:

• Use $request_body with -b for echo_subrequest_async.
• Use $request_body with -b for echo_subrequest_async with echo_read_request_body.
• Use $request_body_file with -f for echo_subrequest_async.
• Use $request_body_file with -f for echo_subrequest_async with echo_read_request_body.
• Use $echo_request_body with -b for echo_subrequest_async.
• Use $echo_request_body with -b for echo_subrequest_async with echo_read_request_body.

I'm sure there's more combinations. No idea which is correct. Seem to me like none work correctly.