Author : Christopher Biscardi
The previous post explains how to get up and running with Docker machine. This one will be a quick tutorial on setting up a Minecraft server using Machine.
1 Create a new Digital Ocean Machine. We need a 1gb server due to Java’s requirements, so we’ll specify the 1gb DO variant:
>machine-docker create -d digitalocean --digitalocean-access-token=$DO_TOKEN --digitalocean-size=1gb biscarch-minecraft
INFO[0000] Creating SSH key...
INFO[0000] Creating Digital Ocean droplet...
INFO[0003] Waiting for SSH...
INFO[0155] "biscarch-minecraft" has been created and is now the active machine. To point Docker at this machine, run: export DOCKER_HOST=$(machine url) DOCKER_AUTH=identity
2 Run the command suggested to activate the Digital Ocean machine. Remember that we re-named our binaries, so our command will look slightly different:
export DOCKER_HOST=$(machine-docker url) DOCKER_AUTH=identity
3 After creating the machine, we can run a Minecraft server. Notice that we’ve accepted the EULA using an environment variable.
> machine-docker-1.3.1-dev-identity-auth run -itp 25565:25565 -e EULA=true itzg/minecraft-server
The authenticity of host "$ip:2376" can't be established.
Remote key ID XXXX
Are you sure you want to continue connecting (yes/no)? yes
Unable to find image 'itzg/minecraft-server:latest' locally
Pulling repository itzg/minecraft-server
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Status: Downloaded newer image for itzg/minecraft-server:latest
--2014-12-27 06:06:21-- https://s3.amazonaws.com/Minecraft.Download/versions/versions.json
Resolving s3.amazonaws.com (s3.amazonaws.com)... 54.231.244.4
Connecting to s3.amazonaws.com (s3.amazonaws.com)|54.231.244.4|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 20681 (20K) [application/octet-stream]
Saving to: 'STDOUT'
100%[====================================================================================>] 20,681 --.-K/s in 0.1s
2014-12-27 06:06:22 (149 KB/s) - written to stdout [20681/20681]
Downloading minecraft_server.1.8.1.jar ...
[06:06:33] [Server thread/INFO]: Starting minecraft server version 1.8.1
[06:06:33] [Server thread/INFO]: Loading properties
[06:06:33] [Server thread/INFO]: Default game type: SURVIVAL
[06:06:33] [Server thread/INFO]: Generating keypair
[06:06:33] [Server thread/INFO]: Starting Minecraft server on *:25565
[06:06:33] [Server thread/INFO]: Using epoll channel type
[06:06:34] [Server thread/WARN]: Failed to load user banlist:
java.io.FileNotFoundException: banned-players.json (No such file or directory)
at java.io.FileInputStream.open(Native Method) ~[?:1.7.0_65]
at java.io.FileInputStream.<init>(FileInputStream.java:146) ~[?:1.7.0_65]
at com.google.common.io.Files.newReader(Files.java:86) ~[minecraft_server.1.8.1.jar:?]
at su.g(SourceFile:124) ~[minecraft_server.1.8.1.jar:?]
at po.z(SourceFile:99) [minecraft_server.1.8.1.jar:?]
at po.<init>(SourceFile:25) [minecraft_server.1.8.1.jar:?]
at pp.i(SourceFile:172) [minecraft_server.1.8.1.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:418) [minecraft_server.1.8.1.jar:?]
at java.lang.Thread.run(Thread.java:745) [?:1.7.0_65]
[06:06:34] [Server thread/WARN]: Failed to load ip banlist:
java.io.FileNotFoundException: banned-ips.json (No such file or directory)
at java.io.FileInputStream.open(Native Method) ~[?:1.7.0_65]
at java.io.FileInputStream.<init>(FileInputStream.java:146) ~[?:1.7.0_65]
at com.google.common.io.Files.newReader(Files.java:86) ~[minecraft_server.1.8.1.jar:?]
at su.g(SourceFile:124) ~[minecraft_server.1.8.1.jar:?]
at po.y(SourceFile:91) [minecraft_server.1.8.1.jar:?]
at po.<init>(SourceFile:27) [minecraft_server.1.8.1.jar:?]
at pp.i(SourceFile:172) [minecraft_server.1.8.1.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:418) [minecraft_server.1.8.1.jar:?]
at java.lang.Thread.run(Thread.java:745) [?:1.7.0_65]
[06:06:34] [Server thread/WARN]: Failed to load operators list:
java.io.FileNotFoundException: ops.json (No such file or directory)
at java.io.FileInputStream.open(Native Method) ~[?:1.7.0_65]
at java.io.FileInputStream.<init>(FileInputStream.java:146) ~[?:1.7.0_65]
at com.google.common.io.Files.newReader(Files.java:86) ~[minecraft_server.1.8.1.jar:?]
at su.g(SourceFile:124) ~[minecraft_server.1.8.1.jar:?]
at po.A(SourceFile:107) [minecraft_server.1.8.1.jar:?]
at po.<init>(SourceFile:29) [minecraft_server.1.8.1.jar:?]
at pp.i(SourceFile:172) [minecraft_server.1.8.1.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:418) [minecraft_server.1.8.1.jar:?]
at java.lang.Thread.run(Thread.java:745) [?:1.7.0_65]
[06:06:34] [Server thread/WARN]: Failed to load white-list:
java.io.FileNotFoundException: whitelist.json (No such file or directory)
at java.io.FileInputStream.open(Native Method) ~[?:1.7.0_65]
at java.io.FileInputStream.<init>(FileInputStream.java:146) ~[?:1.7.0_65]
at com.google.common.io.Files.newReader(Files.java:86) ~[minecraft_server.1.8.1.jar:?]
at su.g(SourceFile:124) ~[minecraft_server.1.8.1.jar:?]
at po.C(SourceFile:123) [minecraft_server.1.8.1.jar:?]
at po.<init>(SourceFile:30) [minecraft_server.1.8.1.jar:?]
at pp.i(SourceFile:172) [minecraft_server.1.8.1.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:418) [minecraft_server.1.8.1.jar:?]
at java.lang.Thread.run(Thread.java:745) [?:1.7.0_65]
[06:06:34] [Server thread/INFO]: Preparing level "world"
[06:06:34] [Server thread/INFO]: Preparing start region for level 0
[06:06:35] [Server thread/INFO]: Preparing spawn area: 4%
[06:06:36] [Server thread/INFO]: Preparing spawn area: 7%
[06:06:37] [Server thread/INFO]: Preparing spawn area: 9%
[06:06:38] [Server thread/INFO]: Preparing spawn area: 11%
[06:06:39] [Server thread/INFO]: Preparing spawn area: 15%
[06:06:40] [Server thread/INFO]: Preparing spawn area: 17%
[06:06:41] [Server thread/INFO]: Preparing spawn area: 20%
[06:06:42] [Server thread/INFO]: Preparing spawn area: 29%
[06:06:43] [Server thread/INFO]: Preparing spawn area: 40%
[06:06:44] [Server thread/INFO]: Preparing spawn area: 55%
[06:06:46] [Server thread/INFO]: Preparing spawn area: 70%
[06:06:47] [Server thread/INFO]: Preparing spawn area: 82%
[06:06:48] [Server thread/INFO]: Preparing spawn area: 95%
[06:06:48] [Server thread/INFO]: Done (14.248s)! For help, type "help" or "?"
4 If we ignore the files that we didn’t create for things like the banned players list, that’s all we have to do to run the server! Launch Minecraft and select Multiplayer:
5 Select “Add Server”
6 Name it whatever you want. To get the server address, run machine-docker url.
7 After clicking done, we should see our server:
8 After clicking play the server, we get a nice new world!
Spawning servers is cool, but how do we keep the data around after the container is killed?
1 Let’s take a look inside a running Minecraft container.
> machine-docker-1.3.1-dev-identity-auth ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
94cf3f854fd8 itzg/minecraft-server:latest "/start-minecraft" About a minute ago Up About a minute 0.0.0.0:25565->25565/tcp sad_pare
> machine-docker-1.3.1-dev-identity-auth exec -it 94c bash
minecraft@94cf3f854fd8:/data$ ls
banned-ips.json banned-players.json eula.txt logs minecraft_server.1.8.1.jar ops.json server.properties usercache.json whitelist.json world
2 kill the old server (we ran it using -it so Control-C should kill it. If you chose to run it with -d, just use machine-docker-1.3.1-dev-identity-auth ps and machine-docker-1.3.1-dev-identity-auth kill $container_id
3 After killing the server, we will get kicked from the game:
4 We can see that there were quite a few files in the /data directory. We’re going to mount a volume there using /opt/craft on the host. Notice that we’ve also set the Message of the Day (MOTD).
machine-docker-1.3.1-dev-identity-auth run -dp 25565:25565 -e EULA=true -e 'MOTD=Crafty Crafting!' -v /opt/craft:/data itzg/minecraft-server
5 Let’s ssh in to the Digital Ocean host and see if we have any files:
> machine-docker ssh
root@docker:~# ls /opt/craft/
banned-ips.json banned-players.json eula.txt logs minecraft_server.1.8.1.jar ops.json server.properties usercache.json whitelist.json world
6 Voila! We have a bunch of files. Now we reconnect to the server (using the Minecraft app) and spend some time doing something (say, chopping down a tree). After that, kill the server as before. The files will stay on the Digital Ocean machine, so we can just restart the server using the same volume mount:
machine-docker-1.3.1-dev-identity-auth run -dp 25565:25565 -e EULA=true -e 'MOTD=Crafty Crafting!' -v /opt/craft:/data itzg/minecraft-server
7 And look at that, we’ve still cutting down our tree! The server was saved!
Let’s check out a new seed using the configuration files.
1 Now we’ll re-run our server with a level seed. It should be added to /opt/craft/server.properties and we can do that through ssh and vi:
> machine-docker ssh biscarch/minecraft
root@docker:~# vi /opt/craft/server.properties
2 server.properties looks something like this (we’ve just changed the level-seed)
root@docker:~# cat /opt/craft/server.properties
#Minecraft server properties
#Sat Dec 27 10:00:14 UTC 2014
spawn-protection=16
max-tick-time=60000
generator-settings=
force-gamemode=false
allow-nether=true
gamemode=0
enable-query=false
player-idle-timeout=0
difficulty=1
spawn-monsters=true
op-permission-level=4
resource-pack-hash=
announce-player-achievements=true
pvp=true
snooper-enabled=true
level-type=DEFAULT
hardcore=false
enable-command-block=false
max-players=20
network-compression-threshold=256
max-world-size=29999984
server-port=25565
texture-pack=
server-ip=
spawn-npcs=true
allow-flight=false
level-name=world
view-distance=10
resource-pack=
spawn-animals=true
white-list=false
generate-structures=true
online-mode=true
max-build-height=256
level-seed=1785852800490497919
use-native-transport=true
enable-rcon=false
motd=Crafty Crafting\!
3 Now we should be able to blow away /opt/craft/world (if it exists in the container) and our world will get rebuilt:
rm -rf /opt/craft/world
4 run the server with the volume attached:
machine-docker-1.3.1-dev-identity-auth run -dp 25565:25565 -e EULA=true -e 'MOTD=Crafty Crafting!' -v /opt/craft:/data itzg/minecraft-server
5 After starting the server with the new seed, just play the server as before (it should still be listed).
Turn around and you should see:
We can use docker machine to ssh into the server and edit /opt/craft/server.properties, which holds a bunch of data we may want to edit. Then just restart the container