Introduction

The DLT Adapter, also referred to as the DLT Interface is a component used by the Blockchain Connector to interact with the Blockchain technology in a transparent way. It is provided as a REST API. Keep in mind that this is a WIP and it is not production-ready yet.

It is built using TypeScript 4.7.4 with express 4.17.3. It interacts with the blockchain through the smart contracts provided in https://github.com/alastria/DOME-blockchain_smart_contracts/tree/main.

Main features:

• Blockchain node selection for all the Blockchain interaction.
• DOME Events publishing.
• DOME Events subscription.
• Retrieval of active DOME Events between dates.

Getting Started

Prerequisites

• Node 14.20.0
• Docker Desktop
• Git
• The aforementioned smart contracts deployed on the EVM network to be used.

Application profiles

• DEBUG: this profile can be setted via the DEBUG environment variable. Setting this variable to "*" enables extensive logging to the API.

OpenAPI specification

You can see the OpenAPI specification at /docs

Tweaking the component to connect to an EVM blockchain

To configure the component to connect to a certain EVM blockchain you need to:

• Deploy the smart contract at https://github.com/alastria/DOME-blockchain_smart_contracts/tree/main in your blockchain network.
• Change the contract address and ABI env variables as defined in .env file to fit the one deployed in your network.
• Change the block number from which all events will be considered legit events i.e. not test events although written by trusted entities of DOME, not events written in earyly development phases.

"Bare metal" installation

• Clone the DLT Adapter project git clone git@github.com:alastria/DOME-blockchain_connector-dlt_interface.git
• Put the rpc address of the evm blokchain node to be used by default in the .env file.
• Put the iss identifier of the legal entity in which name events are going to be published (it can and will be your legal entity in most cases) in the .env file. This is the hash of your Organization Identifier as established by eIDAS regulation.
• Put the private key of the Ethereum account that is going to be publishing the events through the blockchain node in the .env file.
• Put the DOME Events contract address of your EVM compatible blockchain in the .env file.
• Put the DOME Events contract ABI of the contract deployed in your EVM compatible blockchain in the .env file.
• Put the DOME Production block number of the EVM network from which events will be considered as legit in the .env file.
• Create the Docker image of the component by using the Dockerfile at the root directory of the project.
• Execute the image in a docker container.
• The REST API will be available at http://localhost:8080/

Installation using the Docker image

• Get the docker image from https://quay.io/repository/digitelts/dlt-adapter
• Run the docker image in a container indicating the .env file after setting all the env variables in the .env file as commented before.
• The REST API will be available at http://localhost:8080/

Installation using the Helm Chart

• Add Alastria Helm Chart repository at https://github.com/alastria/helm-charts as a Helm repository
• Set all the env variables in the helm chart values.yml file.
• Install the Helm Chart with helm install dlt-adapter dlt-adapter --values dlt-adapter/values.yml
• The REST API will be available at http://localhost:8080/

License

• Apache License 2.0

Acknowledgments

Thanks to DOME project teams, Alastria, and IN2 for their contributions to our project and their expertise at a proceedings and technical level. We are honored to have work with such professional and king partners, and we look forward to future collaborations together.

Authors

• DigitelTS, Alejandro Nieto
• DigitelTS, Alejandro Alfonso
• DigitelTS, Victor Quiroga

Document Version

• v0.0.1