Local Crypto.org Chain and Cronos Stack

WARNING: All the accounts, keys and mnemonics in this repository are publicly exposed and must not be used in places with monetary value.

This project helps to quickly created a local CRO family chains stack using Docker with customizable configurations:

• Crypto.org Chain
• Cronos
• IBC-channel

This is useful for performing experiments without setting up from scratch nor to interact with the public networks.

Prerequisites

• Docker

Quick Start

make all
make start
# Enjoy!

Custom Build and Configuration

make all command perform a series of make actions to create the default chain stack for you. Two of the major steps in the make all is make init and make prepare which are corresponding to the init and prepare Phases.

Init Phase

make init

Init phase creates the default configurations that are commonly shared between all the nodes. i.e. Binary, Configurations, Default accounts and Consensus params. These configurations are usually propagated too all the nodes.

If you want to change the network params, you can modify the assets in assets folder accordingly.

Prepare Phase

make prepare

Prepare phase propagates the assets and generate multiple validators and nodes depending on the setup. This phase are usually useful if you want to create distinctions between the nodes for your experiment.

Common Makefile Targets

Target	Phase	Description
make download-binary	init	Download or build binary from a specific version. You can specify the chain and hermes versions as specified in the Makefile header.
make init	init	Initialize the chains and hermes in the assets folder. This can be used to bootstrap the assets and ten that you can customize the setup.
make prepare	prepare	Prepare the runtime environment including preparing the default accounts with balances and generate the validators details.
make start	runtime	Start the runtime by creating and running all the chain nodes and hermes.
make stop	runtime	Stop the runtime.
make restart	runtime	Restart the runtime.
make logs	runtime	Follow the runtime logs.
make logs-crypto-org-chain	runtime	Follow the Crypto.org Chain runtime logs.
make logs-cronos	runtime	Follow the Cronos runtime logs.
make logs-hermes	runtime	Follow the Hermes runtime logs.
make tendermint-unsafe-reset-all	N/A	This action is non-reversible. Reset chain runtime to initial state.
make unsafe-clear-assets	N/A	This action is non-reversible. Clear assets folder except go/, shared/ and src/ folders inside.
make unsafe-clear-runtime	N/A	This action is non-reversible. Clear runtime folder.

Commands

A few handy commands are provided to help you pre-fill the connections details such that you can interact with local chain stack without a hassell:

Script Path	Description
./cmd/chain-maind	Interact with Crypto.org Chain. Behaves similar to chain-maind with extra features
./cmd/cronosd	Interact with Cronos. Behaves similar to cronosd with extra features
./cmd/hermes	Interact with Hermes. Behaves the same as hermes
./cmd/list-account	List all account address, balances and private key

System Design and Defaults

This section covers the system design highlights and some of default values that you may be interested to modify.

Minimum Gas Prices

Defaults

The default minimum gas prices of each chain is configured as below

Chain	Minimum Gas Prices
Crypto.org Chain	0.025basecro
Cronos	5000basecro,0stake

How to change

To change the minimum gas prices, there are two places you have to modify:

• Chain configuration
  • assets/crypto-org-chain/home/config/app.toml and/or assets/cronos/home/config/app.toml
• Hermes configuration
  • assets/hermes/.hermes/config.toml

Hermes

IBC Channel Keep Alive Cron Job

To keep the IBC client active, an IBC transfer cron job is executed every regular interval. This interval can be configured in the docker-compose.yml. Default is to run every 1 minute.

Two accounts named relayer-keepalive are created in the created Crypto.org Chain and Cronos. IBC transfer cron job make uses of these accounts and transfer CRO to each other and trigger the client updates to keep the channel alive.

Project Structure

Folder	Description
assets/	Build time assets including source file, binaries and configuration before copying to runtime
assets/cronos	Cronos assets
assets/cronos/chain	Cronos binary
assets/cronos/home	Cronos initialized home folder. This will be copied to runtime on make prepare
assets/crypto-org-chain	Crypto.org Chain assets
assets/crypto-org-chain/chain	Crypto.org Chain binary
assets/crypto-org-chain/home	Crypto.org Chain initialized home folder. This will be copied to runtime on make prepare
assets/go	Cache folder for go build dependencies
assets/hermes	Hermes assets
assets/hermes/.hermes	Hermes initialized home folder. This will be copied to runtime on make prepare
assets/hermes/bin	Hermes binary
assets/shared	Shared folder that is mounted as /shared to the container when running ./cmd/chain-maind and ./cmd/cronosd
assets/src/cronos	Cronos source code for custom build
assets/src/crypto-org-chain	Crypto.org Chain source code for custom build
assets/src/hermes	Hermes source code for custom build
cmd/	Contains commands to interact with the docker service as if running a local command
cmd/chain-maind	An easy chain-maind CLI that has access to the local network
cmd/cronosd	An easy cronods CLI that has access to the local network
cmd/hermes	An easy hermes CLI that has access to the local network
cmd/list-account	List all account address, balances and private key
cronos	Cronos docker resources
crypto-org-chain	Crypto.org Chain docker resources
docker	Build docker resources
docker/scripts	Scripts for build toolbox docker image
docker/buildpack.Dockerfile	Base image Dockerfile with necessary build dependencies for all the images
docker/toolbox.Dockerfile	Build toolbox Dockerfile
hermes	Hermes docker resources
runtime/	Runtime environment of the chain services
scripts/	Scripts used by Makefile
docker-compose.yml	docker-compose file generated by Makefile for the local network

List of Docker Images

make build-image creates the following Docker images:

Image Name	Description
local-cro-chain/crypto-org-chain	Crypto.org Chain chain-maind CLI and runtime
local-cro-chain/cronos	Cronos chain-maind CLI and runtime
local-cro-chain/hermes	Hermes runtime docker. It will create IBC channel if it is not created yet.
local-cro-chain/hermes-cli	Hermes CLI

Docker Compose Architecture

Network

A docker network named local-cro-chain-network is created upon docker compose creation. This allow you to run a docker container attaching to the network and interact with the services.

Example:

NETWORK_ID=$(docker network ls | grep 'local-cro-chain-network' | awk '{ print $1}')
docker run --network=$NETWORK_ID ...

Host Port Exposure

Unique ports are assigned the following services of each nodes and exposed to the host network. For the exact port number assignments, refer to the generated docker-compose.yml.

Service	Applicable Chain	Port Range
Tendermint	Both	26650+
gRPC	Both	9090+
LCD	Both	1310+
Prometheus	Both	8090+
ETH JSON RPC	Cronos	8540+

Container Naming

Each docker compose service is assigned a unique name. This allow the host to retrieve the information of these services and interact programmatically. Refer to generated docker-compose.yml for the container name of your interest.

Example - Query Tendermint RPC of the 1st Crypto.org Chain validator:

HOST_PORT=$(docker inspect local-cro-chain-cronos-validator0 | jq -r '.[0].NetworkSettings.Ports."26657/tcp"[0].HostPort')
curl "http://127.0.0.1:${HOST_PORT}"

Custom SSL Certificate

If your network is behind a proxy or has self-signed certificates, you can force the build process to skip SSL verification. There are two options to do so:

1. Provide INSECURE_SKIP_SSL_VERIFY to make target

Note this is only respected by certain commands such as curl but not the others

INSECURE_SKIP_SSL_VERIFY=1 make all

2. Provide an optional certificates

If you have the SSL certificate, this is usually the more reliable way to avoid any SSL certification error arose from self-signed certificate.

1. Copy your self-signed certificate to ./docker/certificates.pem.
2. Run make target as normal.

Note ./docker/certificates.pem will not be committed to Git.