# Running a Network Node

This project lets you set up a local replica of the Optimistic Ethereum chain (either the main one or the Kovan testnet). [New
transactions are submitted either to the sequencer outside of Ethereum or to the Canonical Transaction Chain on
L1](https://research.paradigm.xyz/optimism#data-availability-batches). To submit transactions via a replica, set
`SEQUENCER_CLIENT_HTTP` to a sequencer URL.

## Architecture

You need two components to replicate Optimistic Ethereum:

- `data-transport-layer`, which retrieves and indexes blocks from L1. To access L1 you need an Ethereum Layer 1 provider, such as
  [Infura](https://infura.io/).

- `l2geth`, which provides an Ethereum node where you applications can connect and run API calls.

## Resource requirements

The `data-transport-layer` should run with 1 CPU and 256Mb of memory.

The `l2geth` process should run with 1 or 2 CPUs and between 4 and 8Gb of memory.

With this configuration a synchronization from block 0 to current height is expect to take about 8 hours.

## Software Packages

These packages are required to run the replica:

1. [Docker](https://www.docker.com/)
1. [Docker compose](https://docs.docker.com/compose/install/)

## Configuration

To configure the project, clone this repository and copy either `default-kovan.env` or `default-mainnet.env` file to `.env`.

Review the `SHARED_ENV_PATH` configurations, no changes are required, but depending on the use case, you may need copy these examples to a new directory and make your changes.

!! Update DATA_TRANSPORT_LAYER__L1_RPC_ENDPOINT to a valid endpoint !!

### Settings

Change any other settings required for your environment

| Variable                 | Purpose                                                  | Default
| ------------------------ | -------------------------------------------------------- | -----------
| COMPOSE_FILE             | The yml files to use with docker-compose                 | replica.yml:replica-shared.yml
| ETH_NETWORK              | Ethereum Layer1 and Layer2 network (mainnet,kovan)       | kovan (change to `mainnet` for the production network)
| DATA_TRANSPORT_LAYER__L1_RPC_ENDPOINT | An endpoint for the L1 network, either kovan or mainnet.
| DATA_TRANSPORT_LAYER__L2_RPC_ENDPOINT | Optimistic endpoint, such as https://kovan.optimism.io or https://mainnet.optimism.io
| REPLICA_HEALTHCHECK__ETH_NETWORK_RPC_PROVIDER | The L2 endpoint to check the replica against | (typically the same as the DATA_TRANSPORT_LAYER__L2_RPC_ENDPOINT)
| SEQUENCER_CLIENT_HTTP | The L2 sequencer to forward tx to  | (typically the same as the DATA_TRANSPORT_LAYER__L2_RPC_ENDPOINT)
| SHARED_ENV_PATH          | Path to a directory containing env files                 | [a directory under ./kustomize/replica/envs](https://github.com/optimisticben/op-replica/tree/main/kustomize/replica/envs)
| GCMODE                   | Whether to run l2geth as an `archive` or `full` node     | archive
| L2GETH_IMAGE_TAG         | L2geth version                                           | 0.5.8 (see below)
| DTL_IMAGE_TAG            | Data transport layer version                             | latest (see below)
| HC_IMAGE_TAG             | Health check version                                     | latest (see below)
| L2GETH_HTTP_PORT         | Port number for the l2geth RPC endpoint                  | 9991
| L2GETH_WS_PORT           | Port number for the l2geth WebSockets endpoint           | 9992
| DTL_PORT                 | Port number for the DTL endpoint, for troubleshooting    | 7878
| GETH_INIT_SCRIPT         | The script name to run when initializing l2geth          | A file under kustomize/replica/bases/configmaps/

### Docker Image Versions

We recommend using the latest versions of both docker images. Find them as GitHub tags
[here](https://github.com/ethereum-optimism/optimism/tags) and as published Docker images linked in the badges:

| Package                                                                                                                         | Docker                                                                                                                                                                                                              |
| ------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [`@eth-optimism/l2geth`](https://github.com/ethereum-optimism/optimism/tree/master/l2geth)                                      | [![Docker Image Version (latest by date)](https://img.shields.io/docker/v/ethereumoptimism/l2geth)](https://hub.docker.com/r/ethereumoptimism/l2geth/tags?page=1&ordering=last_updated)                             |
| [`@eth-optimism/data-transport-layer`](https://github.com/ethereum-optimism/optimism/tree/master/packages/data-transport-layer) | [![Docker Image Version (latest by date)](https://img.shields.io/docker/v/ethereumoptimism/data-transport-layer)](https://hub.docker.com/r/ethereumoptimism/data-transport-layer/tags?page=1&ordering=last_updated) |
| [`@eth-optimism/replica-healthcheck`](https://github.com/ethereum-optimism/optimism/tree/master/packages/replica-healthcheck) | [![Docker Image Version (latest by date)](https://img.shields.io/docker/v/ethereumoptimism/replica-healthcheck)](https://hub.docker.com/r/ethereumoptimism/replica-healthcheck/tags?page=1&ordering=last_updated) |


## Usage


| Action | Command |
| - | - |
| Start the replica (after which you can access it at `http://localhost:L2GETH_HTTP_PORT` | `docker-compose up -d` |
| Get the logs for `l2geth` | `docker-compose logs -f l2geth-replica` |
| Get the logs for `data-transport-layer` | `docker-compose logs -f data-transport-layer` |
| Stop the replica | `docker-compose down` |


## Sync Check
 
There is a sync check container. It fails at startup because at that point the replica is not running yet. It exposes metrics on port 3000, which you could pick up with a Prometheus. You can view its status with this command:

```sh
docker-compose logs -f replica-healthcheck
```

## Registration

[Register here](https://groups.google.com/a/optimism.io/g/optimism-announce) to get announcements, such as notifications of when you're supposed to update your replica.