Hydra Control Plane for Hydra Doom

Orchestrating API server that provides "Managed Hydra Head" instance access to players of hydra-doom.

Getting started

First, we need to generate an admin key that manages state in Hydra heads:

cardano-cli address key-gen --normal-key --verification-key-file admin.vk --signing-key-file admin.sk

If you don't want to run it locally on port 8000, reconfigure by amending Rocket.toml.

Next, we need to ensure the control plane can reach a locally running hydra-node. To get started quickly, we'll prepare an offline mode head which is directly open and has funds owned by the generated admin key:

hydra-node gen-hydra-key --output-file hydra

curl https://raw.githubusercontent.com/cardano-scaling/hydra/0.17.0/hydra-cluster/config/protocol-parameters.json \
  | jq '.utxoCostPerByte = 0' > protocol-parameters.json

cat > utxo.json << EOF
{
  "0000000000000000000000000000000000000000000000000000000000000000#0": {
    "address": "$(cardano-cli address build --verification-key-file admin.vk --testnet-magic 1)",
    "value": {
      "lovelace": 1000000000
    }
  }
}
EOF

To start the hydra-node:

hydra-node offline \
  --hydra-signing-key hydra.sk \
  --ledger-protocol-parameters protocol-parameters.json \
  --initial-utxo utxo.json \
  --persistence-dir hydra-state

Then, in a dedicated terminal, build & start with:

cargo run --release

Rocket.toml

You can configure the server in the Rocket.toml.

Each [abc] section defines a "Profile", which you can switch to by setting the ROCKET_PROFILE environment variable. The default is [default].

Nodes

You can configure remote hydra nodes with a [[profile.nodes]] entry, which can be repeated any number of times.

Each node has a local_url, which is the URL the control plane will attempt to connect on, and a remote_url, which is the URL the control plane will direct others to connect on. Don't include the port here.

port is the port to connect on

admin_key_file must point to the admin key generated above.

persisted means the node is persisting events to disk, and is reserved for the on-site cabinets, while remote players will be directed to non-persistent nodes.

reserved means the node will only be assigned games that pass the ?reserved flag

region means the aws region the node is in, to give preference for people who ask for ?region=

stats_file is an optional file where stats for this node should be persisted

max_players determines the maximum number of players that can be assigned to this node at once

Hosts

You can configure nodes in bulk by configuring [[profile.hosts]] instead.

It has most of the same flags, except:

port is replaced by start_port and end_port; stats_file is replaced by stats_file_prefix; the port will be added to this prefix to determine the actual file

All other flags get copied to the Node config.