Add minecraft service

This is an initial configuration to restore old services.

Obviously, vendoring everything in a tarball is pretty awful, and if I
ever wanted to open source this, that would be a problem.

I intend to create a proper derivation in time, but including mods is
difficult from some initial experimentation.

.gitattributes

@@ -0,0 +1 @@
+*.tar.gz filter=lfs diff=lfs merge=lfs -text

Makefile

@@ -5,7 +5,7 @@ tlaternet.qcow2:
 	nix-shell -p qemu --run 'qemu-img create -f qcow2 $@ 10G'
 
 run: result tlaternet.qcow2
-	QEMU_OPTS="-m 4096 -nographic" QEMU_NET_OPTS="hostfwd=tcp::2222-:2222,hostfwd=tcp::8000-:80" ./result/bin/run-tlaternet-vm
+	QEMU_OPTS="-m 4096 -nographic" QEMU_NET_OPTS="hostfwd=tcp::2222-:2222,hostfwd=tcp::8000-:80,hostfwd=tcp::25565-:25565" ./result/bin/run-tlaternet-vm
 
 format: $(wildcard etc/nixos/**/*.nix)
 	nix-shell -p nixpkgs-fmt --run 'nixpkgs-fmt $^'

etc/nixos/configuration.nix

@@ -15,6 +15,7 @@
     ./services/gitea.nix
     ./services/nextcloud.nix
     ./services/tlaternet.nix
+    ./services/minecraft.nix
   ];
 
   networking = {
@@ -32,6 +33,7 @@
         443
         2222
         2221
+        25565
       ];
     };
   };

etc/nixos/services/minecraft.nix

@@ -0,0 +1,126 @@
+{ pkgs, ... }:
+
+let
+  ops = pkgs.writeText "ops.json" (builtins.toJSON [
+    {
+      uuid = "140d177a-966f-41b8-a4c0-e305babd291b";
+      name = "TLATER";
+      level = 4;
+      bypassesPlayerLimit = true;
+    }
+  ]);
+  whitelist = pkgs.writeText "whitelist.json" (builtins.toJSON [
+    {
+      uuid = "59cd1648-14a4-4bcf-8f5a-2e1bde678f2c";
+      name = "romino25";
+    }
+    {
+      uuid = "0ab6e3d1-544a-47e7-8538-2e6c248e49a4";
+      name = "lasi25";
+    }
+    {
+      uuid = "140d177a-966f-41b8-a4c0-e305babd291b";
+      name = "TLATER";
+    }
+  ]);
+  properties = pkgs.writeText "server.properties" ''
+    #Minecraft server properties
+    #Sun Jul 19 16:04:54 GMT 2020
+    max-tick-time=60000
+    generator-settings=
+    allow-nether=true
+    force-gamemode=false
+    gamemode=0
+    enable-query=false
+    player-idle-timeout=0
+    difficulty=1
+    spawn-monsters=true
+    op-permission-level=4
+    pvp=false
+    snooper-enabled=true
+    level-type=DEFAULT
+    hardcore=false
+    enable-command-block=false
+    max-players=4
+    network-compression-threshold=256
+    resource-pack-sha1=
+    max-world-size=29999984
+    server-port=25565
+    server-ip=
+    spawn-npcs=true
+    allow-flight=true
+    level-name=world
+    view-distance=15
+    resource-pack=
+    spawn-animals=true
+    white-list=true
+    generate-structures=true
+    online-mode=true
+    max-build-height=256
+    level-seed=
+    prevent-proxy-connections=false
+    use-native-transport=true
+    motd=Adventures met die broers
+    enable-rcon=false
+  '';
+
+in
+{
+  docker-containers = {
+    minecraft = {
+      image = "tlaternet/minecraft";
+      imageFile = pkgs.dockerTools.buildImage {
+        name = "tlaternet/minecraft";
+        tag = "latest";
+        runAsRoot = ''
+          mkdir -p /var/lib/
+          ${pkgs.gzip}/bin/gzip -dc ${./configs/minecraft.tar.gz} | ${pkgs.gnutar}/bin/tar -xf - -C /var/lib
+          echo 'eula=true' > /var/lib/minecraft/eula.txt
+          cp -f ${properties} /var/lib/minecraft
+        '';
+        config = {
+          Cmd = [ "${pkgs.jre_headless}/bin/java"
+                  "-Xms2G"
+                  "-Xmx2G"
+                  # Using recommended flags from https://mcflags.emc.gs
+                  "-XX:+UseG1GC"
+                  "-XX:+ParallelRefProcEnabled"
+                  "-XX:MaxGCPauseMillis=200"
+                  "-XX:+UnlockExperimentalVMOptions"
+                  "-XX:+DisableExplicitGC"
+                  "-XX:+AlwaysPreTouch"
+                  "-XX:G1NewSizePercent=30"
+                  "-XX:G1MaxNewSizePercent=40"
+                  "-XX:G1HeapRegionSize=8M"
+                  "-XX:G1ReservePercent=20"
+                  "-XX:G1HeapWastePercent=5"
+                  "-XX:G1MixedGCCountTarget=4"
+                  "-XX:InitiatingHeapOccupancyPercent=15"
+                  "-XX:G1MixedGCLiveThresholdPercent=90"
+                  "-XX:G1RSetUpdatingPauseTimePercent=5"
+                  "-XX:SurvivorRatio=32"
+                  "-XX:+PerfDisableSharedMem"
+                  "-XX:MaxTenuringThreshold=1"
+                  "-jar"
+                  "/var/lib/minecraft/forge-1.12.2-14.23.5.2854.jar"
+                  "nogui"
+                ];
+          Volumes = {
+            "/var/lib/minecraft/world" = {};
+          };
+          WorkingDir = "/var/lib/minecraft";
+          ExposedPorts = {
+            "25565" = {};
+          };
+        };
+      };
+      ports = [
+        "25565:25565"
+      ];
+      volumes = [
+        "${ops}:/var/lib/minecraft/ops.json:ro"
+        "${whitelist}:/var/lib/minecraft/whitelist.json:ro"
+      ];
+    };
+  };
+}