homelab/server/config/minecraft

Connecting to a server's CLI

To connect to a server's RCON Minecraft console, run docker exec -it minecraft_e6 rcon-cli --password thanksitzg Do not prefix commands with /.

• https://github.com/itzg/docker-minecraft-server#interactive-and-color-console
• https://github.com/itzg/docker-minecraft-server#use-rcon-commands

Updating MC-Router mappings

MC-Router must be running for all active MC connections. Restarting it kicks everyone off their servers

To update the mappings while running, use docker exec mc-router /mc-router --mapping <new-mapping string>

Before Starting a Server

Check the following server.properties values:

Parameter	Value	Why
allow-flight	true	Many modded features trigger Minecraft's flight detection. Allow flight to prevent wrongful bans.
enable-rcon	true	This overrides any rcon settings in the compose file. Enable rcon to interact with the server's command line
max-tick-time	600 normally, 120000 when pre-genning chunks	Increase the max tick time to prevent the hang watchdog from killing the server when pregenning chunks
rcon.password	thanksitzg	Set a simple password to protect the rcon port
rcon.port	25575	Set this to what itzg's rcon-cli expects as default
view-distance	10 for lightweight servers, 6 for heavy servers	View distance has great impact on server load

Chunk Pregenerator

Chunk pregeneration is very valuable for getting a playable SMP server expierence.

Installing Chunk Pregenerator

Make sure that the Chunk Pregenerator mod is installed. It is compatible with most Minecraft versions between 1.7.2 and 1.16.5.

Pregenerating World Spawn

To pregen chunks, first connect to the server's RCON CLI. Then, run the following, pregen start gen radius Pregen SQUARE 0 0 100 This should take about half an hour and will generate about 40,000 chunks (2r^2). For a job closer to 8 hours, run pregen start gen radius Pregen SQUARE 0 0 500 Which will generate about 500,000 chunks.

A Ryzen 7 5800X generates chunks at about 1.35 chunks per tick (27 chunks per second @ 20 TPS).

Automating Chunk Pregen

Itzg's container supports RCON_CMDS_FIRST_CONNECT and RCON_CMDS_LAST_DISCONNECT environment variables, which allow us to automatically begin pregenerating chunks when no one is connected, and pause this task when players begin joining.

Use these variables when the server supports pregen and would benefit from this:

RCON_CMDS_STARTUP= |-
    /pregen start gen radius Pregen SQUARE 0 0 500
RCON_CMDS_FIRST_CONNECT= |-
    /pregen pause
RCON_CMDS_LAST_DISCONNECT= |-
    /pregen continue

This pregen will significantly reduce load on the server during playtime unless:

• Players explore beyond the pregenerated regions, or
• Players join the server before a significant area can be pregenerated.