I was able to do it pretty simply in Node-Red, so I set it up there and deleted the question. I put an http listener on the NR flow and call that URL from MSR when I want to trigger the TCP connection. I'll give this solution a try, as having it all in one place seems like a good idea.
EDIT:
So I tried and am getting this. I'm working on it, but you'll probably post a solution before I can figure it out. I'm running MSR in Docker on a RPi4.
Rule<SET>" (rule-kvmgurr3:S) step 3 Shell action failed command "echo '?\"id\?' | nc -C -q 1 192.168.0.25 55443" (1)
nc: unrecognized option: C
BusyBox v1.31.1 () multi-call binary.
Usage: nc [OPTIONS] HOST PORT - connect
nc [OPTIONS] -l -p PORT [HOST] [PORT] - listen
-e PROG Run PROG after connect (must be last)
-l Listen mode, for inbound connects
-lk With -e, provides persistent server
-p PORT Local port
-s ADDR Local address
-w SEC Timeout for connects and final net reads
-i SEC Delay interval for lines sent
-n Don't do DNS resolution
-u UDP mode
-v Verbose
-o FILE Hex dump traffic
-z Zero-I/O mode (scanning)
Edit 2:
I used my usual brute force method of Googling various terms and mashing the keyboard (aka trial and error by a Linux novice) and finally made this work on my RPi4 Docker install of MSR.
The '-C' didn't work, but I was able to add $'\r\n' to the end of the echo command which I believe achieved the same effect.
The '-q 1' didn't work, but I was able to use '-w 1' which again I believe has the same effect.
So I end up with a shell command of:
echo '{"id":1,"method":"set_power","params":["on", "smooth", 250]}'$'\r\n' | nc -w 1 192.168.0.25 55443
0dcb676f-e03e-4464-9b6c-0a4ac39f4176-image.png
P.S. - I read the 'category topic guide' between my first reply and this edit and realize that I'm probably violating at least one of those rules. I got a good laugh from this part of that post: " I wrote Reactor as a tool for you to use to solve your automation/logic problems, not as a tool for me to use to solve your automation/logic problems." Hopefully I'm living up to that part a little bit by figuring this out for myself (with a initial help from Patrick).
