Deploying docker-compose containers

Question

I'm trying to deploy an app that's built with docker-compose, but it feels like I'm going in completely the wrong direction.

1. I have everything working locally—docker-compose up brings up my app with the appropriate networks and hosts in place.
2. I want to be able to run the same configuration of containers and networks on a production machine, just using a different .env file.

My current workflow looks something like this:

docker save [web image] [db image] > containers.tar
zip deploy.zip containers.tar docker-compose.yml
rsync deploy.zip user@server

ssh user@server
unzip deploy.zip ./
docker load -i containers.tar

docker-compose up

At this point, I was hoping to be able to run docker-compose up again when they get there, but that tries to rebuild the containers as per the docker-compose.yml file.

I'm getting the distinct feeling that I'm missing something. Should I be shipping over my full application then building the images at the server instead? How would you start composed containers if you were storing/loading the images from a registry?

Answer 1

The problem was that I was using the same docker-compose.yml file in development and production.

The app service didn't specify a repository name or tag, so when I ran docker-compose up on the server, it just tried to build the Dockerfile in my app's source code directory (which doesn't exist on the server).

I ended up solving the problem by adding an explicit image field to my local docker-compose.yml.

version: '2'
services:
  web:
    image: 'my-private-docker-registry:latest'
    build: ./app

Then created an alternative compose file for production:

version: '2'
services:
  web:
    image: 'my-private-docker-registry:latest'
    # no build field!

After running docker-compose build locally, the web service image is built with the repository name my-private-docker-registry and the tag latest.

Then it's just a case of pushing the image up to the repository.

docker push 'my-private-docker-registry:latest'

And running docker pull, it's safe to stop and recreate the running containers, with the new images.