Testing Ethereum Substreams-powered Subgraphs(MIPs TheGraph program)

2 min readJun 8, 2023

What is Firehose?

Blockchain-agnostic way of storing and retrieving data
Makes it easy for applications to handle “forks” using “cursors”
Extract everything you would ever need into flat files
Flat files allow massively parallel processing using things like substreams*
Unit of storage are “Merged Blocks” aka “Firehose Blocks”

install execution client:

Firehose-instrumented execution client (fork of geth) running as a full nod Recommended build: v1.11.5-fh2.2–1 as of April 19, 2023 https://github.com/streamingfast/go-ethereum/releases/download/geth-v1.11.5-fh2.2-1/geth_linux

2. install consensus client Prysm:

mkdir prysm && cd prysm
curl https://raw.githubusercontent.com/prysmaticlabs/prysm/master/prysm.sh --output prysm.sh && chmod +x prysm.sh

# ### Generate JWT Secret
openssl rand -hex 32 | tr -d "\n" > "jwt.hex"

3. Run an execution client:

# Firehose config.yml for Ethereum mainnet

start:
  args:
  - merger
  - firehose
  - reader-node
  - relayer
  - combined-index-builder
  flags:
    data-dir: /var/lib/firehose
    common-chain-id: "1"
    common-network-id: "1"
    reader-node-path: /root/geth_linux
    substreams-rpc-endpoints: $ETHEREUM_ARCHIVE_RPC
    substreams-enabled: true
    substreams-partial-mode-enabled: true
    firehose-grpc-listen-addr: 0.0.0.0:13042
    substreams-request-stats-enabled: true
    reader-node-arguments: "--mainnet
             --datadir=/var/lib/firehose/geth
             --ipcpath=/var/lib/firehose/reader/ipc
             --http --http.api=eth,net,web3
             --authrpc.jwtsecret /root/geth/jwtsecret
             --http.port=8555 --http.addr=0.0.0.0 --http.vhosts=*
             --firehose-enabled --port=30303 --cache=2048"

Start fireeth with the following command: fireeth -c /etc/firehose/config.yml start

4. Run a beacon node using Prysm:

./prysm.sh beacon-chain --execution-endpoint=http://localhost:8545 --jwt-secret=/root/geth/jwtsecret --checkpoint-sync-url=https://mainnet.checkpoint.sigp.io/ --genesis-beacon-api-url=https://mainnet.checkpoint.sigp.io/

Configure Graph Node for substreams-powered subgraphs

[chains.${FIREHOSE_CHAIN}]
shard = "primary"
provider = [ 
{ label = "firehose", details = { type = "firehose", url = "${FIREHOSE_RPC}" } }
]

Sync and serve a substreams-powered subgraph: QmeWyu8pzV3zViL5nz813NxKSab7REh9qJBivjzkCzE9Vw

Testing Ethereum Substreams-powered Subgraphs(MIPs TheGraph program)

Written by Olga L