YEEEESSS!!!! THIS!!! Thank you! I've been able to hobble together a script now that I have a Synology automated task calling early each morning after world backups are complete. I'm so very grateful to you all. I've learned a lot. A proper "stop" is being issues now which reduces the chance of world corruption which would make my family very very grumpy.

Here's the script just in case someone finds themselves in a similar situation as me. This is not my wheelhouse and it's not pretty. I know it can be better, but I've spent too much time on this as it is and need to go fix a washing machine now. Ugh...

#!/bin/bash

# Define the countdown duration in seconds
countdown_duration=20

# Function to send a message to the Docker container
send_cmd() {
  cmd="$1"
  sudo sh -c "echo '$cmd' | socat EXEC:'docker attach mcbe-world',pty STDIN"
}

# Announce
announce_text="Daily server restart commencing in $countdown_duration seconds..."
send_cmd "say $announce_text"

# Perform the countdown
for ((i = $countdown_duration; i >= 1; i--)); do
  #echo "Restaring in $i seconds"
  countdown_text="Restarting in $i seconds"
  send_cmd "say $countdown_text"
  sleep 1
done

# Gracefully shutdown server
#  Note: stopping forces the mcbe container to restart on it's own. 
#  Not sure why that's the case, but it's the end result I want...
send_cmd "stop"

P.S. I really need to figure out how to get the RCON solution working because that would be a more elegant way to handle things.

P.P.S Example run (yes, the timing and spelling were updated after this screenshot 😁)

Ooh. I was not aware of the RCON protocol. Looking into now. This may be the exact thing I need. Thanks for the lead.

Well,RCON has not fared well. Afaik, I've set things up correctly but the client I'm using (mcrcon) keep returning Error 111: Connection refused.

• This post got me to direct things to the right IP which I could get with docker inspect -f '{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}' mcbe-world.
• docker port mcbe-world shows that the rcon port is open
• the server.properties files for the mc server has the relevant rcon lines

AFAIK /stop is not just a shell command, it needs to be given to stdin of the minecraft process. The broader question here is how to pass something to stdin of a running process.

docker exec mcbe-world just gives access to the container so commands can be executed. /stop is a specific command for the MC server running in that container. The process is already running and I am trying to figure out how to issue a command to it... and the other comment in this post referencing "rcon" might be a solution...

This looked so promising.

Via SSH, I can indeed use docker attach and from within I can issue a stop for MC server. Works fine.

However, the Synology task scheduler via DSM doesn't seem to be able to similarly attach and then issue the stop command. I get this back via email (for when a scheduled task fails):

Task Scheduler has completed a scheduled task.

Task: MC Graceful Restart Start time: Tue, 29 Aug 2023 17:19:41 -0500 Stop time: Tue, 29 Aug 2023 17:19:42 -0500 Current status: 127 (Interrupted) Standard output/error:

the input device is not a TTY /bin/bash: line 1: stop: command not found