Make significant changes to the book

book/src/interop-scenarios.md

@@ -0,0 +1,97 @@
+# Interop Scenarios
+
+Here we demonstrate some expected interop scenarios.
+
+All scenarios assume a working [development environment](./setup.md) and
+commands are based in the `target/release` directory (this is the build dir for
+`cargo`).
+
+Additional functions can be found in the [interop
+cheat-sheet](./interop-cheat-sheet.md).
+
+### Table of contents
+
+- [Starting from a`validator_count, genesis_time` tuple](#quick-start)
+- [Starting a node from a genesis state file](#state-file)
+- [Starting a validator client](#val-client)
+- [Exporting a genesis state file](#export) from a running Lighthouse
+	node
+
+
+<a name="quick-start"></a>
+### Start beacon node given a validator count and genesis_time
+
+
+To start a brand-new beacon node (with no history) use:
+
+```
+$ ./beacon_node testnet -f quick 8 1567222226
+```
+> Notes:
+>
+> - This method conforms the ["Quick-start
+genesis"](https://github.com/ethereum/eth2.0-pm/tree/6e41fcf383ebeb5125938850d8e9b4e9888389b4/interop/mocked_start#quick-start-genesis)
+method in the `ethereum/eth2.0-pm` repository.
+> - The `-f` flag ignores any existing database or configuration, backing them
+>   up before re-initializing.
+> - `8` is the validator count and `1567222226` is the genesis time.
+> - See `$ ./beacon_node testnet quick --help` for more configuration options.
+
+<a name="state-file"></a>
+### Start Beacon Node given a genesis state file
+
+A genesis state can be read from file using the `testnet file` subcommand.
+There are three supported formats:
+
+- `ssz` (default)
+- `json`
+- `yaml`
+
+Start a new node using `/tmp/genesis.ssz` as the genesis state:
+
+```
+$ ./beacon_node testnet --spec minimal -f file ssz /tmp/genesis.ssz
+```
+
+> Notes:
+>
+> - The `-f` flag ignores any existing database or configuration, backing them
+>   up before re-initializing.
+> - See `$ ./beacon_node testnet file --help` for more configuration options.
+
+<a name="val-client"></a>
+### Start an auto-configured validator client
+
+To start a brand-new validator client (with no history) use:
+
+```
+$ ./validator_client testnet -b insecure 0 8
+```
+
+> Notes:
+>
+> - The `-b` flag means the validator client will "bootstrap" specs and config
+>   from the beacon node.
+> - The `insecure` command dictates that the [interop keypairs](https://github.com/ethereum/eth2.0-pm/tree/6e41fcf383ebeb5125938850d8e9b4e9888389b4/interop/mocked_start#pubkeyprivkey-generation)
+>   will be used.
+> - The `0 8` indicates that this validator client should manage 8 validators,
+>   starting at validator 0 (the first deposited validator).
+> - The validator client will try to connect to the beacon node at `localhost`.
+>   See `--help` to configure that address and other features.
+> - The validator client will operate very unsafely in `testnet` mode, happily
+>   swapping between chains and creating double-votes.
+
+<a name="export"></a>
+### Exporting a genesis file
+
+Genesis states can downloaded from a running Lighthouse node via the HTTP API. Three content-types are supported:
+
+- `application/json`
+- `application/yaml`
+- `application/ssz`
+
+Using `curl`, a genesis state can be downloaded to `/tmp/genesis.ssz`:
+
+```
+$ curl --header "Content-Type: application/ssz" "localhost:5052/beacon/state/genesis" -o /tmp/genesis.ssz
+```