docker-minecraft-server/docs/configuration/server-properties.md

By default, the server configuration will be created and set based on the following environment variables, but only the first time the server is started. If the `server.properties` file already exists, the values in them will not be changed.

If you prefer to manually manage the `server.properties` file, set `OVERRIDE_SERVER_PROPERTIES` to "false". Similarly, you can entirely skip the startup script's creation of `server.properties` by setting `SKIP_SERVER_PROPERTIES` to "true".

> NOTE: to clear a server property, set the variable to an empty string, such as `-e RESOURCE_PACK=""`. A variables that maps to a server property that is unset, is ignored and the existing `server.property` is left unchanged. 

### Message of the Day

The message of the day, shown below each server entry in the client UI, can be changed with the `MOTD` environment variable, such as

    -e MOTD="My Server"

If you leave it off, a default is computed from the server type and version, such as

    A Paper Minecraft Server powered by Docker

That way you can easily differentiate between several servers you may have started.

The section symbol (§) and other unicode characters are automatically converted to allow [formatting codes](https://minecraft.fandom.com/wiki/Formatting_codes) to be used consistently with all server versions. For example,

     -e MOTD="A §l§cMinecraft§r §nserver"

renders

![](../img/motd-example.png)

To produce a multi-line MOTD, you will need to double escape the newline such as

    -e MOTD="Line one\\nLine two"

### Difficulty

The difficulty level (default: `easy`) can be set like:

```
docker run -d -e DIFFICULTY=hard ...
```

Valid values are: `peaceful`, `easy`, `normal`, and `hard`, and an
error message will be output in the logs if it's not one of these
values.

### Whitelist Players

!!! note 
    
    It is very important to set this with servers exposed to the internet where you want only limited players to join.

To whitelist players for your Minecraft server, you can:  

- Provide a list of usernames and/or UUIDs separated by commas via the `WHITELIST` environment variable  
  `docker run -d -e WHITELIST=user1,uuid2 ...`
- Provide the url or path to a whitelist file via `WHITELIST_FILE` environment variable  
  `docker run -d -e WHITELIST_FILE=/extra/whitelist.json ...`

When either is set, [whitelisting of connecting users](https://minecraft.fandom.com/wiki/Server.properties#white-list) is enabled . If managing the list manually, `ENABLE_WHITELIST` can be set to "true" to set the `white-list` property.

If whitelist configuration already exists, `WHITELIST_FILE` will not be retrieved and any usernames in `WHITELIST` are **added** to the whitelist configuration. You can enforce regeneration of the whitelist on each server startup by setting `OVERRIDE_WHITELIST` to "true". This will delete the whitelist file before processing whitelist configuration.

!!! note

    You can provide both `WHITELIST_FILE` and `WHITELIST`, which are processed in that order.

!!! note 
    
    UUIDs passed via `WHITELIST` need to be the dashed variant, otherwise it not be recognised and instead added as a username.
    
    If running Minecraft 1.7.5 or earlier, these variables will apply to `white-list.txt`, with 1.7.6 implementing support for `whitelist.json`. Make sure your `WHITELIST_FILE` is in the appropriate format.

To [enforce the whitelist changes immediately](https://minecraft.fandom.com/wiki/Server.properties#enforce-whitelist) when whitelist commands are used , set `ENFORCE_WHITELIST` to "true".

### Op/Administrator Players

Similar to the whitelist, to add users as operators (aka adminstrators) to your Minecraft server, you can:  

- Provide te url or path to an ops file via `OPS_FILE` environment variable  
    `docker run -d -e OPS_FILE=https://config.example.com/extra/ops.json ...`
- Provide a list of usernames and/or UUIDs separated by commas via the `OPS` environment variable  
    `docker run -d -e OPS=user1,uuid2 ...`

If ops configuration already exists, `OPS_FILE` will not be retrieved and any usernames in `OPS` are **added** to the ops configuration. You can enforce regeneration of the ops configuration on each server startup by setting `OVERRIDE_OPS` to "true". This will delete the ops file before processing ops configuration.

!!! note 

    Similar to whitelists, you can provide both `OPS_FILE` and `OPS`, and Minecraft 1.7.5 or earlier will use `ops.txt` rather than `ops.json`.

### Enable/disable initial selection of datapacks

New to [22W42A](https://www.minecraft.net/en-us/article/minecraft-snapshot-22w42a), datapacks with feature flags can be controlled before initial world creation by setting these to a comma separated list of packs:

- `INITIAL_ENABLED_PACKS`
  such as "update_1_20,bundle"
- `INITIAL_DISABLED_PACKS`

### Server icon

A server icon can be configured using the `ICON` variable. The image will be automatically
downloaded, scaled, and converted from any other image format:

    docker run -d -e ICON=http://..../some/image.png ...

The server icon which has been set doesn't get overridden by default. It can be changed and overridden by setting `OVERRIDE_ICON` to `TRUE`.

    docker run -d -e ICON=http://..../some/other/image.png -e OVERRIDE_ICON=TRUE...

### RCON

RCON is **enabled by default** to allow for graceful shut down the server and coordination of save state during backups. RCON can be disabled by setting `ENABLE_RCON` to "false".

The default password is randomly generated if `RCON_PASSWORD` has not been set.

**DO NOT MAP THE RCON PORT EXTERNALLY** unless you aware of all the consequences and have set a **secure password** with `RCON_PASSWORD`. 

!!! info 

    Mapping ports (`-p` command line or `ports` in compose) outside the container and docker networking needs to be a purposeful choice. Most production Docker deployments do not need any of the Minecraft ports mapped externally from the server itself.

By default, the server listens for RCON on port 25575 within the container. It can be changed with `RCON_PORT` but only do this if you have a very good reason. **DO NOT change `rcon.port` via `server.properties`** or integrations will break.

### Query

Enabling this will enable the gamespy query protocol.
By default the query port will be `25565` (UDP) but can easily be changed with the `QUERY_PORT` variable.

    docker run -d -e ENABLE_QUERY=true

### Max players

By default max players is 20, you can increase this with the `MAX_PLAYERS` variable.

    docker run -d -e MAX_PLAYERS=50

### Max world size

This sets the maximum possible size in blocks, expressed as a radius, that the world border can obtain.

    docker run -d -e MAX_WORLD_SIZE=10000

### Allow Nether

Allows players to travel to the Nether.

    docker run -d -e ALLOW_NETHER=true

### Announce Player Achievements

Allows server to announce when a player gets an achievement.

    docker run -d -e ANNOUNCE_PLAYER_ACHIEVEMENTS=true

### Enable Command Block

Enables command blocks

     docker run -d -e ENABLE_COMMAND_BLOCK=true

### Force Gamemode

Force players to join in the default game mode.

- false - Players will join in the gamemode they left in.
- true - Players will always join in the default gamemode.

  `docker run -d -e FORCE_GAMEMODE=false`

### Generate Structures

Defines whether structures (such as villages) will be generated.

- false - Structures will not be generated in new chunks.
- true - Structures will be generated in new chunks.

  `docker run -d -e GENERATE_STRUCTURES=true`

### Hardcore

If set to true, players will be set to spectator mode if they die.

    docker run -d -e HARDCORE=false

### Snooper

If set to false, the server will not send data to snoop.minecraft.net server.

    docker run -d -e SNOOPER_ENABLED=false

### Max Build Height

The maximum height in which building is allowed.
Terrain may still naturally generate above a low height limit.

    docker run -d -e MAX_BUILD_HEIGHT=256

### Max Tick Time

The maximum number of milliseconds a single tick may take before the server watchdog stops the server with the message, A single server tick took 60.00 seconds (should be max 0.05); Considering it to be crashed, server will forcibly shutdown. Once this criteria is met, it calls System.exit(1).
Setting this to -1 will disable watchdog entirely

    docker run -d -e MAX_TICK_TIME=60000

### Spawn Animals

Determines if animals will be able to spawn.

    docker run -d -e SPAWN_ANIMALS=true

### Spawn Monsters

Determines if monsters will be spawned.

    docker run -d -e SPAWN_MONSTERS=true

### Spawn NPCs

Determines if villagers will be spawned.

    docker run -d -e SPAWN_NPCS=true

### Set spawn protection

Sets the area that non-ops can not edit (0 to disable)

    docker run -d -e SPAWN_PROTECTION=0

### View Distance

Sets the amount of world data the server sends the client, measured in chunks in each direction of the player (radius, not diameter).
It determines the server-side viewing distance.

    docker run -d -e VIEW_DISTANCE=10

### Level Seed

If you want to create the Minecraft level with a specific seed, use `SEED`, such as

    -e SEED=1785852800490497919

If using a negative value for the seed, make sure to quote the value such as:

    -e SEED="-1785852800490497919"

### Game Mode

By default, Minecraft servers are configured to run in Survival mode. You can
change the mode using `MODE` where you can either provide the [standard
numerical values](http://minecraft.gamepedia.com/Game_mode#Game_modes) or the
shortcut values:

- creative
- survival
- adventure
- spectator (only for Minecraft 1.8 or later)

For example:

    docker run -d -e MODE=creative ...

### PVP Mode

By default, servers are created with player-vs-player (PVP) mode enabled. You can disable this with the `PVP`
environment variable set to `false`, such as

    docker run -d -e PVP=false ...

### Level Type and Generator Settings

By default, a standard world is generated with hills, valleys, water, etc. A different level type can
be configured by setting `LEVEL_TYPE` to [an expected type listed here](https://minecraft.fandom.com/wiki/Server.properties#level-type).

For some of the level types, `GENERATOR_SETTINGS` can be used to further customize the world generation [as described here](https://minecraft.fandom.com/wiki/Server.properties#generator-settings).

### Custom Server Resource Pack

You can set a link to a custom resource pack and set it's checksum using the `RESOURCE_PACK` and `RESOURCE_PACK_SHA1` options respectively, the default is blank:

    docker run -d -e 'RESOURCE_PACK=http://link.com/to/pack.zip?=1' -e 'RESOURCE_PACK_SHA1=d5db29cd03a2ed055086cef9c31c252b4587d6d0'

You can enforce the resource pack on clients by setting `RESOURCE_PACK_ENFORCE` to `TRUE` (default: `FALSE`).

### Level / World Save Name

You can either switch between world saves or run multiple containers with different saves by using the `LEVEL` option,
where the default is "world":

    docker run -d -e LEVEL=bonus ...

> **NOTE:** if running multiple containers be sure to either specify a different `-v` host directory for each
`LEVEL` in use or don't use `-v` and the container's filesystem will keep things encapsulated.

> **INFO** Refer to the [data directory](../data-directory.md) section for a visual description of where the `$LEVEL` directory is situated.

### Online mode

By default, server checks connecting players against Minecraft's account database. If you want to create an offline server or your server is not connected to the internet, you can disable the server to try connecting to minecraft.net to authenticate players with environment variable `ONLINE_MODE`, like this

    docker run -d -e ONLINE_MODE=FALSE ...

### Allow flight

Allows users to use flight on your server while in Survival mode, if they have a mod that provides flight installed.

    -e ALLOW_FLIGHT=TRUE|FALSE

### Server name

The server name (e.g. for bungeecord) can be set like:

    docker run -d -e SERVER_NAME=MyServer ...

### Server port

> **WARNING:** only change this value if you know what you're doing. It is only needed when using host networking and it is rare that host networking should be used. Use `-p` port mappings instead.

If you must, the server port can be set like:

    docker run -d -e SERVER_PORT=25566 ...

**however**, be sure to change your port mapping accordingly and be prepared for some features to break.

### Other server property mappings

| Environment Variable              | Server Property                   |
| --------------------------------- | --------------------------------- |
| PLAYER_IDLE_TIMEOUT               | player-idle-timeout               |
| BROADCAST_CONSOLE_TO_OPS          | broadcast-console-to-ops          |
| BROADCAST_RCON_TO_OPS             | broadcast-rcon-to-ops             |
| ENABLE_JMX                        | enable-jmx-monitoring             |
| SYNC_CHUNK_WRITES                 | sync-chunk-writes                 |
| ENABLE_STATUS                     | enable-status                     |
| ENTITY_BROADCAST_RANGE_PERCENTAGE | entity-broadcast-range-percentage |
| FUNCTION_PERMISSION_LEVEL         | function-permission-level         |
| NETWORK_COMPRESSION_THRESHOLD     | network-compression-threshold     |
| OP_PERMISSION_LEVEL               | op-permission-level               |
| PREVENT_PROXY_CONNECTIONS         | prevent-proxy-connections         |
| USE_NATIVE_TRANSPORT              | use-native-transport              |
| ENFORCE_WHITELIST                 | enforce-whitelist                 |
| ENABLE_WHITELIST                  | white-list and whitelist          |
| SIMULATION_DISTANCE               | simulation-distance               |