hyperledger fabric ca - Is there a method to replicate container using docker compose?

Question

I am not using container orchestration techniques like docker swarm or Kubernetes. My goal is to replicate the services of ca0 with different IP:Port to listen the request. This is required to maintain High Availability (HA) of services provided by ca0. The compose of ca0 is shown below:

version: '2'

networks:
  byfn:

services:
  ca0:
    image: hyperledger/fabric-ca:$IMAGE_TAG
    environment:
      - FABRIC_CA_HOME=/etc/hyperledger/fabric-ca-server
      - FABRIC_CA_SERVER_CA_NAME=ca-org1
      - FABRIC_CA_SERVER_TLS_ENABLED=true
      - FABRIC_CA_SERVER_TLS_CERTFILE=/etc/hyperledger/fabric-ca-server-config/ca.org1.example.com-cert.pem
      - FABRIC_CA_SERVER_TLS_KEYFILE=/etc/hyperledger/fabric-ca-server-config/key.pem
      - FABRIC_CA_SERVER_PORT=7054
    ports:
      - "7054:7054"
    command: sh -c 'fabric-ca-server start --ca.certfile /etc/hyperledger/fabric-ca-server-config/ca.org1.example.com-cert.pem --ca.keyfile /etc/hyperledger/fabric-ca-server-config/key.pem -b admin:adminpw -d'
    volumes:
      - ./crypto-config/peerOrganizations/org1.example.com/ca/:/etc/hyperledger/fabric-ca-server-config
    container_name: ca0_peerOrg1
    networks:
      - byfn

Again, To replicate the same service, the service named it to ca1, container name ca1_peerOrg, I just change the Port And appended it to the previous ca0 service defined as above. ca1 service is defined as below:

# Replicated CA
ca1:
    image: hyperledger/fabric-ca:$IMAGE_TAG
    environment:
      - FABRIC_CA_HOME=/etc/hyperledger/fabric-ca-server
      - FABRIC_CA_SERVER_CA_NAME=ca-org1
      - FABRIC_CA_SERVER_TLS_ENABLED=true
      - FABRIC_CA_SERVER_TLS_CERTFILE=/etc/hyperledger/fabric-ca-server-config/ca.org1.example.com-cert.pem
      - FABRIC_CA_SERVER_TLS_KEYFILE=/etc/hyperledger/fabric-ca-server-config/key.pem
      - FABRIC_CA_SERVER_PORT=8054
    ports:
      - "8054:8054"
    command: sh -c 'fabric-ca-server start --ca.certfile /etc/hyperledger/fabric-ca-server-config/ca.org1.example.com-cert.pem --ca.keyfile /etc/hyperledger/fabric-ca-server-config/key.pem -b admin:adminpw -d'
    volumes:
      - ./crypto-config/peerOrganizations/org1.example.com/ca/:/etc/hyperledger/fabric-ca-server-config
    container_name: ca1_peerOrg1
    networks:
      - byfn

And I run the docker compose file and got an error as:

        gopal@gopal:~/Dappdev/first/fabric-samples/first-network$ docker-compose -f docker-compose-ca.yaml up  
ERROR: The Compose file './docker-compose-ca.yaml' is invalid because:
Invalid top-level property "ca1". Valid top-level sections for this Compose file are: services, version, networks, volumes, and extensions starting with "x-".

You might be seeing this error because you're using the wrong Compose file version. Either specify a supported version (e.g "2.2" or "3.3") and place your service definitions under the `services` key, or omit the `version` key and place your service definitions at the root of the file to use version 1.
For more on the Compose file format versions, see https://docs.docker.com/compose/compose-file/

My approach to creating replicated containers is not the right way.

How to replicate a container with the different selected port?

question from:https://stackoverflow.com/questions/65642480/is-there-a-method-to-replicate-container-using-docker-compose

Answer 1

You can make use of YAML anchor and merge syntax:

services:
  ca0: &name-me  # <- this is an anchor
    image: hyperledger/fabric-ca:$IMAGE_TAG
    environment:
      - FABRIC_CA_HOME=/etc/hyperledger/fabric-ca-server
      - FABRIC_CA_SERVER_CA_NAME=ca-org1
      - FABRIC_CA_SERVER_TLS_ENABLED=true
      - FABRIC_CA_SERVER_TLS_CERTFILE=/etc/hyperledger/fabric-ca-server-config/ca.org1.example.com-cert.pem
      - FABRIC_CA_SERVER_TLS_KEYFILE=/etc/hyperledger/fabric-ca-server-config/key.pem
      - FABRIC_CA_SERVER_PORT=7054
    ports:
      - "7054:7054"
    command: sh -c 'fabric-ca-server start --ca.certfile /etc/hyperledger/fabric-ca-server-config/ca.org1.example.com-cert.pem --ca.keyfile /etc/hyperledger/fabric-ca-server-config/key.pem -b admin:adminpw -d'
    volumes:
      - ./crypto-config/peerOrganizations/org1.example.com/ca/:/etc/hyperledger/fabric-ca-server-config
    container_name: ca0_peerOrg1
    networks:
      - byfn
  ca1:
    <<: *name-me  # <- this is a merge (<<) with an alias (*name-me)
    # keys below merge notation override those that declared under anchor
    # so this:
    ports:
    - "8054:7054"
    # replaces default 'ports' (the whole key)

The alias *name-me takes everything under the anchor &name-me but using merge <<: notation you can override some properties of the anchor (ports in this example). I take it that you can't use swarm or kubernetes, because this is not a great way to manage replicas. Go swarm or K8s if you can.