Running Zeko's DA Node

A critical component of any rollup system is the data availability layer. This layer is responsible for storing all the transaction data that occurs on the rollup.

In this guide we will create a da-layer node that receives transaction data from the Zeko L2 rollup.

Not covered in this guide:

• Running the archive stack used to query historical data. See Running Zeko's Archive Node.
• Exposing your da-layer to the internet

We will use docker compose to define the whole stack in a single file.

TL;DR skip to the Bootstrap process

Prerequisites

System Requirements

• Linux or macOS (Windows WSL2 works too)
• 1 CPU core, 2GB RAM

Installed Software

• Docker

Overview

In the diagram above you see:

• Zeko's sequencer sending transactions to da-layer
• the optional archive stack that can index and serve historical data from your DA node

Project Structure

Layout of the project directory:

project-root/
└── docker-compose.yaml

Note: docker-compose.yaml is using docker volumes to store data. If you prefer to mount local directories instead - change accordingly.

Wallets

To run a da-layer you will need:

• da-signer - Holds the wallet credentials that is used by da-layer.
• da-layer - Each da-layer node is started with its wallet.

Volumes/files

Volumes	Files	Purpose
keys_data	da-layer-sk	Private key of the DA node
keys_data	da-layer-pk	Public key of the DA node (used by sequencer)
keys_data	da-signer/signer-auth-token	Auth token shared by DA layer and signer
keys_data	da-signer/signer-tls.crt	TLS certificate for DA layer signer
keys_data	da-signer/signer-tls.key	TLS private key for DA layer signer
da-layer_data		Persistent storage for da-layer

Service Overview

• init-config
• da-signer
• da-layer

Ports Exposed

Service	Port	Description
da-layer	1924	da-layer rpc API
da-signer	9001	da-layer signer

---

Bootstrap process

Getting/Creating configuration files

• Copy docker-compose.yaml to your project folder.

  Click to expand docker-compose.yaml

  services:
    init-config:
      image: docker.io/zekolabs/zeko:latest
      container_name: init-config
      working_dir: /data
      volumes:
        - keys_data:/data/keys
      entrypoint:
        - sh
        - -c
      restart: "no"
      command: >
        "while [ ! -f /data/keys/.keys_created ];
          do sleep 2;
        done; exit 0"
    da-signer:
      depends_on:
        init-config:
          condition: service_completed_successfully
      image: docker.io/zekolabs/zeko-da:latest
      container_name: da-signer
      ports:
        - "9001:9001"
      entrypoint: bash -c
      command: |
        "export MINA_PRIVATE_KEY=$(cat /keys/da-layer-sk) && \\
        export ZEKO_SIGNER_AUTH_TOKEN=$(cat /keys/da-signer/signer-auth-token) && \\
        exec zeko-signer \\
        run \\
        --host 0.0.0.0 \\
        --port 9001 \\
        --allow-field-signing \\
        --tls-cert-file /keys/da-signer/signer-tls.crt \\
        --tls-key-file /keys/da-signer/signer-tls.key"
      volumes:
        - keys_data:/keys:ro
      restart: always
    da-layer:
      depends_on:
        da-signer:
          condition: service_started
      image: docker.io/zekolabs/zeko-da:latest
      container_name: da-layer
      ports:
        - "1924:1924"
      environment:
        ZEKO_SIGNATURE_KIND: "testnet"
      entrypoint: bash -c
      command: |
        "export ZEKO_SIGNER_AUTH_TOKEN=$(cat /keys/da-signer/signer-auth-token) && \\
        export ZEKO_SIGNER_TLS_CA_FILE=/keys/da-signer/signer-tls.crt && \\
        exec zeko-da \\
        run-node \\
        --port 1924 \\
        --db-dir /data/db \\
        --signer da-signer:9001 \\
        --network-id testnet"
      volumes:
        - da-layer_data:/data
        - keys_data:/keys:ro
      restart: always
  
  volumes:
    da-layer_data:
    keys_data:

• Start all services

  docker compose up -d

• Create da-layer keys

  1. Enter init-config container:

  docker compose exec -it init-config bash

  Note: This image contains zeko-cli binary.

  2. Create da-layer keypair

  • /data/keys/da-layer-pk
  • /data/keys/da-layer-sk
  • /data/keys/da-signer/signer-auth-token
  • /data/keys/da-signer/signer-tls.crt
  • /data/keys/da-signer/signer-tls.key

  da-signer/signer-auth-token is the random token shared by da-layer and da-signer. da-signer/signer-tls.crt and da-signer/signer-tls.key are the self-signed TLS files used by da-signer.

  The certificate Subject Alternative Name must match the signer host used by --signer. This Docker Compose file uses da-signer, so the SAN is DNS:da-signer.

  Note: Take note of da-layer-pk

  # create `da-layer` keypair
  zeko-cli generate-even-key | while read label1 label2 value; do
  if [ "$label1" = "Private" ]; then
    echo "$value" > da-layer-sk
  elif [ "$label1" = "Public" ]; then
    echo "$value" > da-layer-pk
  fi
  done
  
  mv da-layer-{sk,pk} /data/keys
  
  # create `da-signer` auth token and TLS files
  install -d -m 0700 /data/keys/da-signer
  openssl rand -hex 32 > /data/keys/da-signer/signer-auth-token
  chmod 0600 /data/keys/da-signer/signer-auth-token
  
  DA_SIGNER_HOST=da-signer
  DA_SIGNER_SAN=DNS:$DA_SIGNER_HOST
  openssl req -x509 -newkey rsa:4096 -sha256 -days 3650 -nodes \
    -keyout /data/keys/da-signer/signer-tls.key \
    -out /data/keys/da-signer/signer-tls.crt \
    -subj "/CN=$DA_SIGNER_HOST" \
    -addext "subjectAltName=$DA_SIGNER_SAN"
  chmod 0644 /data/keys/da-signer/signer-tls.crt
  chmod 0600 /data/keys/da-signer/signer-tls.key
  
  touch /data/keys/.keys_created

If all the steps were performed correctly you have the following:

• da-layer getting data from Zeko's L2

Let Zeko know about your DA Layer

In order for you to start receiving transactions from Zeko L2 sequencer you need to:

• Expose your da-layer on the internet
• Contact Zeko and ask to be added to DA node list. You will need to provide:
  • your da-layer public key
  • address:port on which Zeko's sequencer can reach your da-layer

Synchronizing the data

Once your DA node will be added to Zeko's Sequencer, your node will start receiving transactions. Synchronizing might take some time. It depends when did the sequencer receive a hard reset.

If you want to index that data and query it through an archive API, continue with Running Zeko's Archive Node.