How to prevent data loss on restart of Hyperledger fabric in Docker containers

Question

Whenever I restart a Hyperledger Fabric network running on Docker containers, all the previous data in the Hyperledger gets deleted. Do I have a way to avoid this problem?

Answer 1

Store the ledger data in volumes mounted into the docker containers. If you explore the 'Build Your First Network' tutorial, you can get an idea about how you would handle this. Take a close look at the fabric-samples/first-network/base/docker-compose-base.yaml definitions for the orderer and peer nodes. You will find how we preserve the state between restarts.

eg Here is the definition of the orderer. The last volume in the list would preserve the state. The peers are handled similarly:

version: '2'

services:

  orderer.example.com:
    container_name: orderer.example.com
    image: hyperledger/fabric-orderer:$IMAGE_TAG
    environment:
      - ORDERER_GENERAL_LOGLEVEL=INFO
      - ORDERER_GENERAL_LISTENADDRESS=0.0.0.0
      - ORDERER_GENERAL_GENESISMETHOD=file
      - ORDERER_GENERAL_GENESISFILE=/var/hyperledger/orderer/orderer.genesis.block
      - ORDERER_GENERAL_LOCALMSPID=OrdererMSP
      - ORDERER_GENERAL_LOCALMSPDIR=/var/hyperledger/orderer/msp
      # enabled TLS
      - ORDERER_GENERAL_TLS_ENABLED=true
      - ORDERER_GENERAL_TLS_PRIVATEKEY=/var/hyperledger/orderer/tls/server.key
      - ORDERER_GENERAL_TLS_CERTIFICATE=/var/hyperledger/orderer/tls/server.crt
      - ORDERER_GENERAL_TLS_ROOTCAS=[/var/hyperledger/orderer/tls/ca.crt]
    working_dir: /opt/gopath/src/github.com/hyperledger/fabric
    command: orderer
    volumes:
    - ../channel-artifacts/genesis.block:/var/hyperledger/orderer/orderer.genesis.block
    - ../crypto-config/ordererOrganizations/example.com/orderers/orderer.example.com/msp:/var/hyperledger/orderer/msp
    - ../crypto-config/ordererOrganizations/example.com/orderers/orderer.example.com/tls/:/var/hyperledger/orderer/tls
    - orderer.example.com:/var/hyperledger/production/orderer
    ports:
      - 7050:7050