# Minecraft server — itzg NeoForge

## Summary

`itzg/minecraft-server:java21`, NeoForge 1.21.1, offline-mode + authlib-injector
pointing at drasl. Mods come from a local `./server-mods` volume (mounted at
`/mods`), NOT packwiz — see `04-mods.md`. itzg installs MC + NeoForge + libraries
on first boot and auto-syncs `/mods` → `/data/mods` every boot; the stack assumes
the internet is present (for the NeoForge installer), so `TYPE=NEOFORGE` boots
normally every time.

## Server config

```
TYPE=NEOFORGE, VERSION=1.21.1, NEOFORGE_VERSION=21.1.x
REMOVE_OLD_MODS=TRUE          # ./server-mods is the authoritative mod set
volume  ./server-mods:/mods:ro
```

`./server-mods` is populated by `tooling/sync-server-mods.sh` (the `both`/`server`
subset of `mods-sides.json`, copied from `$DISTRIBUTION_WEB_ROOT`). First boot
installs MC + NeoForge + libraries into the `mc_data` volume; every boot itzg
mirrors `/mods` into `/data/mods` and prunes removed ones (`REMOVE_OLD_MODS`).

## Auth / config

```
ONLINE_MODE=FALSE
ENFORCE_SECURE_PROFILE=FALSE                 # pairs with drasl SignPublicKeys=false
JVM_OPTS=-javaagent:/extras/authlib-injector.jar=http://auth.${BASE_DOMAIN}/authlib-injector
```
authlib URL uses the `auth` subdomain; resolves internally via the caddy alias.
(Server still needs the agent even though Fjord clients have it built in.)

Memory: `INIT_MEMORY 4G`, `MAX_MEMORY 10G`, `USE_AIKAR_FLAGS TRUE`.
RCON enabled for mc-backup.

## Server operators (OP)

**Do NOT use the itzg `OPS` env var.** It resolves usernames to UUIDs via a
Mojang lookup, but this server is `ONLINE_MODE=FALSE` with Drasl auth — Drasl
assigns its own UUIDs (not Mojang, not the offline-hash). A Mojang-resolved UUID
would not match the player's real session UUID, so the op entry would be inert
(and could clobber a correct `ops.json` on reboot).

**Op via RCON instead.** The player must have connected at least once so their
real Drasl UUID is cached in `/data/usercache.json`; then `op <name>` writes that
cached UUID to `ops.json`. On the host:

```
ssh cochi
docker exec minecraft rcon-cli list                 # confirm cache / who's on
docker exec minecraft sh -c 'cat /data/usercache.json'   # verify name→UUID cached
docker exec minecraft rcon-cli op <name>
docker exec minecraft sh -c 'cat /data/ops.json'    # verify level 4 + right UUID
```

`ops.json` lives in the `mc_data` volume → persists across restarts; no reboot
needed (takes effect live). Current op: `oier`
(`7fbc9adb-bcf4-3913-9a99-46d46acd1009`), level 4, set 2026-06-21.

## Tasks

- [ ] Compose: authlib URL `http://auth.${BASE_DOMAIN}/authlib-injector`
- [ ] Compose: mount `./server-mods:/mods:ro` + `REMOVE_OLD_MODS=TRUE`
- [ ] Run `tooling/sync-server-mods.sh` before bring-up (populates `./server-mods`)
- [ ] Mount `./runtime` for authlib-injector.jar at `/extras`
- [ ] `depends_on`: drasl (authlib must resolve at boot)
- [ ] Confirm `ENFORCE_SECURE_PROFILE=FALSE` ↔ drasl `SignPublicKeys=false`
- [ ] Verify a client joins with their drasl skin