> ## Documentation Index
> Fetch the complete documentation index at: https://docs.craftsupport.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# The test network

> A container network that runs each server the way a panel host does

Pterodactyl runs each server as a plain JRE process in its own container with the server files on a mounted volume. The harness in `docker-test/` does the same, so what it proves is what a rented network would do rather than what Kubernetes did.

It brings up a standalone MongoDB, a Redis, two shards, a hub and a Velocity proxy on one Docker network, and **none of the shards are declared in `velocity.toml`** — they register themselves, which is the piece that replaced the Kubernetes operator.

## Running it

Needs Docker and about 6 GB of memory.

```bash theme={null}
./gradlew build
./docker-test/setup.sh
docker compose -f /opt/atlas-test/docker-compose.yml up -d
```

The proxy is on `localhost:25577`. `setup.sh` downloads the pinned Paper and Velocity builds, generates one world and copies it to each shard, writes the configuration, and assembles a compose file. It is idempotent.

## What it checks

<CardGroup cols={2}>
  <Card title="The plugins enable" icon="circle-check">
    On the real Paper, Velocity and Java versions, which is the single most likely thing to differ on a host you do not control.
  </Card>

  <Card title="A standalone database works" icon="database">
    The read concern adapts and the log says which it chose.
  </Card>

  <Card title="Self-registration" icon="network-wired">
    Both shards appear on the proxy from their address alone.
  </Card>

  <Card title="Restart and recovery" icon="arrows-rotate">
    Stopping a shard withdraws it and the proxy unregisters it; starting it brings the topology back.
  </Card>
</CardGroup>

RCON is enabled on the shards, so the operator commands can be driven from a script rather than by hand.

```bash theme={null}
python3 /opt/atlas-test/rcon.py r0 25575 atlastest "shard topology"
```

## What it cannot check yet

It cannot walk a player across a border. No headless client speaks this protocol version — node-minecraft-protocol stops one release short — so the crossing, the ghost band, the block mirror and the audit log still need a person with a real client.

<Warning>
  The proxy in the harness runs `online-mode = false` so a test client can connect without a Mojang account. That is the one setting deliberately unlike production; see [Security](/deploy/security).
</Warning>

## Why this exists

Because a full line-by-line review, a green build and a passing unit suite all missed a null dereference that stopped the plugin enabling at all. Field initializers run before the constructor body, so a setting read from one dereferenced a field that was still null. Every shard failed to enable, Paper disabled the plugin, and the server carried on accepting players while owning nothing.

Nothing in the build could see it, because nothing in the build constructs a plugin. Thirty seconds of a real server starting caught it immediately.