CODEWITHSUNDEEP
dockerdocker-composedocker-machinedocker-swarm
Stalin Kay
Stalin Kay

Reputation: 607

Deploying docker-compose as yml in order to be able to scale using the same port

I've successfully managed to deploy a docker-compose.yml using docker-machine. The problem I have is with scaling. Trying to scale a node.js app that uses port 3000. How can I scale a docker-compose service. I know I can use docker-compose scale web=3 in a swarm of 1 node (server) but this doesn't work because I specified port 3000, which results in a conflict.

How can I get it to work in a dynamic manner without resorting to using HAProxy or Nginx?

Dockerfile

FROM node:wheezy
# replace this with your application's default port
EXPOSE 3000
ADD . /install
WORKDIR /install
ENV NODE_PATH /usr/local/lib/node_modules/
RUN npm install -g $(cat packages) && rm -rf npm_cache /tmp/* && npm install
# Install node modules and start
CMD ["npm", "install"]
CMD ["node", "."]

docker-compose.yml

version: "2"
    services:
      web:
        build: .
        ports:
          - "3000:3000"
        links:
          - mongo
        environment:
          - "affinity:image==node:wheezy"
      mongo:
        image: mongo
        volumes:
          - ./appdb:/data/db
    volumes:
      mongo-data:
        driver: local

Upvotes: 2

Views: 617

Answers (1)

DevOps Dan
DevOps Dan

Reputation: 1853

As you are actually BINDING to the host, it wouldn't be possible without a proxy or load balancer.

See this issue on the topic via GitHub where a user was asking a similar question:

https://github.com/docker/compose/issues/3088

Here is an example of how you can do it with a load balancer, making it easy:

https://github.com/vegasbrianc/docker-compose-demo/blob/master/docker-compose.yml

Upvotes: 2

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