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.wiki/w/Formatting_codes) to be used consistently with all server versions. For example, -e MOTD="A §l§cMinecraft§r §nserver" renders ![](../img/motd-example.png) !!! note "Escape unicode" Some Minecraft versions and server types do not support unicode characters, such as §, in `server.properties`. In those cases, an extra "\u00C2" will appear in the file and the client will render those as  characters. Unicode characters can be written as escaped codes by setting the environment variable `SERVER_PROPERTIES_ESCAPE_UNICODE` to "true". To produce a multi-line MOTD, embed a newline character as `\n` in the string, 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. Refer to [the Minecraft wiki](https://minecraft.wiki/w/Difficulty) ### Whitelist Players !!! warning "For public servers" It is very important to consider setting a whitelist of expected players. To whitelist players for your Minecraft server, you can: - Provide a list of usernames and/or UUIDs separated by commas or newlines via the `WHITELIST` environment variable - Provide the URL or container path to a whitelist file via `WHITELIST_FILE` that will be retrieved/copied into the standard location !!! example In a compose file, a text block can be used to improve maintainability, such as ```yaml WHITELIST: | user1 user2 user3 ``` When either is set, [whitelisting of connecting users](https://minecraft.wiki/w/Server.properties#white-list) is enabled. To change the behavior when the whitelist file already exists, set the variable `EXISTING_WHITELIST_FILE` to one of the following options: `SKIP` (default) : Skip processing of the whitelist file when one is already present. This is the same as setting the legacy variable `OVERRIDE_WHITELIST` to "false". `SYNCHRONIZE` : Synchronize the list of users in the file with the `WHITELIST` or `WHITELIST_FILE` provided. When using both, `WHITELIST` will take precedence. This is the same as setting the legacy variable `OVERRIDE_WHITELIST` to "true". `MERGE` : Merge the list of users from `WHITELIST` into the existing file. `WHITELIST_FILE` cannot be used with this option. `SYNC_FILE_MERGE_LIST` : When `WHITELIST_FILE` is provided it will overwrite an existing whitelist file. Also, if `WHITELIST` is provided, then those users will be merged into the newly copied file. !!! note For versions prior to 1.7.3, `white-list.txt` will be maintained instead. Only usernames are supported for those versions. To [enforce the whitelist changes immediately](https://minecraft.wiki/w/Server.properties#enforce-whitelist) when whitelist commands are used , set `ENFORCE_WHITELIST` to "true". If managing the whitelist file manually, `ENABLE_WHITELIST` can be set to "true" to set the `white-list` property. ### Op/Administrator Players Similar to the whitelist, users can be provisioned as operators (aka administrators) to your Minecraft server by - Providing a list of usernames and/or UUIDs separated by commas or newlines via the `OPS` environment variable - Providing the URL or container path to an ops file via `OPS_FILE` that will be retrieved/copied into the standard location !!! example In a compose file, a text block can be used to improve maintainability, such as ```yaml OPS: | user1 user2 user3 ``` To change the behavior when the ops file already exists, set the variable `EXISTING_OPS_FILE` to one of the following options: `SKIP` (default) : Skip processing of the ops file when one is already present. This is the same as setting the legacy variable `OVERRIDE_OPS` to "false". `SYNCHRONIZE` : Synchronize the list of users in the file with the `OPS` or `OPS_FILE` provided. When using both, `OPS` will take precedence. The `level` and `bypassesPlayerLimit` will be retained from previous entries. This is the same as setting the legacy variable `OVERRIDE_OPS` to "true". `MERGE` : Merge the list of users from `OPS` into the existing file. `OPS_FILE` cannot be used with this option. `SYNC_FILE_MERGE_LIST` : When `OPS_FILE` is provided it will overwrite an existing ops file. Also, if `OPS` is provided, then those users will be merged into the newly copied file. !!! note For versions prior to 1.7.3, `ops.txt` will be maintained instead. Only usernames are supported for those versions. ### 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.wiki/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.wiki/w/Server.properties#level-type). For some of the level types, `GENERATOR_SETTINGS` can be used to further customize the world generation. To configure the `GENERATOR_SEETINGS` you need to add the appropriate `GeneratorOptions` JSON configuration. In the case of a superflat world, you may omit the `flat_world_options`. The layers are applied from -64 and up and are added in the order of the list Example for a superflat world: - 1x bedrock - 2x stone - 15x sandstone - Desert biome ```yaml LEVEL_TYPE: FLAT GENERATOR_SETTINGS: >-4 { "layers": [ { "block": "minecraft:bedrock", "height": 1 }, { "block": "minecraft:stone", "height": 2 }, { "block": "minecraft:sandstone", "height": 15 } ], "biome": "minecraft:desert" } ``` For more details, check the [official wiki](https://minecraft.wiki/w/Java_Edition_level_format#generatorOptions_tag_format). ### 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 `$LEVEL` directory is situated. ### Online mode By default, server checks connecting players against Minecraft's account database. If you want to create an offline server or your server is not connected to the internet, you can disable the server to try connecting to minecraft.net to authenticate players with environment variable `ONLINE_MODE`, like this docker run -d -e ONLINE_MODE=FALSE ... ### Allow flight Allows users to use flight on your server while in Survival mode, if they have a mod that provides flight installed. -e ALLOW_FLIGHT=TRUE|FALSE ### Server name The server name (e.g. for bungeecord) can be set like: docker run -d -e SERVER_NAME=MyServer ... ### Server port > **WARNING:** only change this value if you know what you're doing. It is only needed when using host networking and it is rare that host networking should be used. Use `-p` port mappings instead. If you must, the server port can be set like: docker run -d -e SERVER_PORT=25566 ... **however**, be sure to change your port mapping accordingly and be prepared for some features to break. ### Custom server properties Some mods/plugins utilize custom `server.properties` entries which can be declared via the `CUSTOM_SERVER_PROPERTIES` environment variable. The contents must be newline delimited `name=value` pairs. Within a compose file, newline delimited entries can be declared as shown here: ```yaml CUSTOM_SERVER_PROPERTIES: | custom1=value1 defaultworldgenerator-port=f8c04631-f744-11ec-b260-f02f74b094e0 ``` When using `docker run` from a bash shell, the entries must be quoted with the `$'` syntax, such as ``` -e CUSTOM_SERVER_PROPERTIES=$'k1=v1\nk2=v2' ``` ### Other server property mappings | Environment Variable | Server Property | |-----------------------------------|-----------------------------------| | BROADCAST_CONSOLE_TO_OPS | broadcast-console-to-ops | | BROADCAST_RCON_TO_OPS | broadcast-rcon-to-ops | | ENABLE_STATUS | enable-status | | ENFORCE_SECURE_PROFILE | enforce-secure-profile | | 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 | | PLAYER_IDLE_TIMEOUT | player-idle-timeout | | PREVENT_PROXY_CONNECTIONS | prevent-proxy-connections | | SIMULATION_DISTANCE | simulation-distance | | SYNC_CHUNK_WRITES | sync-chunk-writes | | USE_NATIVE_TRANSPORT | use-native-transport |