Emulate private networking with Docker Compose

Sometime testing on mainnet or testnet is not suitable due to we can't control it. We can solve this problem by create a private network that we completely have control. With Docker Compose, we can easily achieve that.

Prerequisites

1. Docker
2. Docker Compose

Create a file to describe containers to run

Create a new empty directory anywhere to store configurations that we are going to create. Then create docker-compose.yml in that directory with the following content:

version: '3'

services:
  zcoind-1:
    container_name: zcoind-1
    image: zcoinofficial/zcoind:latest
    volumes:
      - ./zcoind-1.conf:/home/zcoind/.zcoin/zcoin.conf
  zcoind-2:
    container_name: zcoind-2
    image: zcoinofficial/zcoind:latest
    volumes:
      - ./zcoind-2.conf:/home/zcoind/.zcoin/zcoin.conf
  zcoind-3:
    container_name: zcoind-3
    image: zcoinofficial/zcoind:latest
    volumes:
      - ./zcoind-3.conf:/home/zcoind/.zcoin/zcoin.conf

Create zcoind-1.conf with the following content:

connect=zcoind-2
connect=zcoind-3
listen=1

Create zcoind-2.conf with the following content:

connect=zcoind-1
connect=zcoind-3
listen=1

Create zcoind-3.conf with the following content:

connect=zcoind-1
connect=zcoind-2
listen=1

If you need more nodes just add more configurations for it. You can put testnet=1 in a configuration to emulate testnet or regtest=1 to emulate in regression test mode.

Start/stop nodes

Execute the following command in the directory that we created from previous instruction to start all nodes that we configured:

docker-compose up -d

If you does not have docker image specified in the configuration it will pulled automatically. -d option mean we will start all nodes in a background. Verify if it already running:

docker ps

If you want to see the console output for node 1 use the following command:

docker logs zcoind-1

Verify connections on node 1:

docker exec zcoind-1 zcoin-cli getpeerinfo

You should see it is connected to all nodes that you specified with connect option in the configuration file.

If you want to connect a node on your host machine to nodes in container just use the same connect option. You can find IP address of each container with the following command:

docker inspect zcoind-1

To stop all nodes, execute the following command:

docker-compose down