0dns

This service is responsible for connecting to the network and fetching all the magic blocks from the network which are saved in the DB. There is a Network API which can be used to get latest set of miners and sharders for the network using the magic block.

Setup
Buildding and starting the node
Point to another blockchain
Exposed APIs
Config changes
Cleanup
Network issue

Setup

Clone the repo and run the following command inside the cloned directory

./docker.local/bin/init.sh

Building and Starting the Node

If there is new code, do a git pull and run the following command

./docker.local/bin/build.sh

Go to the bin directory (cd docker.local/bin) and run the container using

./start.sh

Point to another blockchain

You can point the server to any instance of 0chain blockchain you like, Just go to config (docker.local/config) and update the magic_block.json.

By default they are pointing to local network with 4 miners and 1 sharder

You have to get the magic block from the chain you want to connect and update the magic_block.json file.

It will use that file to extract miners and sharders value and use that for further operations.

Exposed APIs

0dns exposes:

Network API

{BASEURL}/network

This API can be used to fetch the latest set of miners and sharder to connect. GoSDK will also uses this API to fetch miner/sharders value on runtime.

Details: https://0chain.net/page-documentation.html#tag/BlockWorker/paths/~1network/get

Magic Block API

{BASEURL}/magic_block

This API can be used to fetch the latest magic block data from network.

Details: https://0chain.net/page-documentation.html#tag/BlockWorker/paths/~1magic_block/get

Config Changes

You can do other config changes as well in 0dns.yaml file itself, Like

Mongo DB connection URL, DB name and pool size

mongo:
  url: mongodb://mongodb:27017
  db_name: block-recorder
  pool_size: 2

Server port

port: 9091

Logging info level

logging:
  level: "info"
  console: false # printing log to console is only supported in development mode

Worker related config

worker:
  magic_block_worker: 5 # in seconds, Frequency to update magic block

Cleanup

Get rid of old data when the blockchain is restarted or if you point to a different network:

./docker.local/bin/clean.sh

Network issue

If there is no test network, run the following command

docker network create --driver=bridge --subnet=198.18.0.0/15 --gateway=198.18.0.255 testnet0

Troubleshooting

When running locally, if http://localhost:9091/network is returning below. Some commands might fail.

{
  "miners": [
    "https://198.18.0.71/",
    "https://198.18.0.72/",
    "https://198.18.0.74/",
    "https://198.18.0.73/"
  ],
  "sharders": [
    "https://198.18.0.81/"
  ]
}

To fix the miner and sharder URLs so it works locally, update docker.local/config/0dns.yaml to disable both use_https and use_path (set to false).

NoSkillGuy / 0dns