We have demonstrated how peers, orderers, and CAs can be configured in docker-compose YAML files. But such configurations are meant to override settings that have already been made by default in the components’ respective images. Though a detailed description of these configurations is beyond the scope of this book, we will list the respective files and mention how a user may make changes to them.
For a peer, a core.yaml file (https://github.com/hyperledger/fabric/blob/release-1.1/sampleconfig/core.yaml) contains all of the important runtime settings, including but not limited to addresses, port numbers, security and privacy, and the gossip protocol. You can create your own file and sync it to the container using a custom Dockerfile instead of the one that is used by the hyperledger/fabric-peer image by default. If you log in to a running peer container (let’s take the Exporter organization’s peer's container from the network we just launched):
docker...