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Development workflow for docker compose: run the dev-version container

I have a pretty typical docker-compose setup: a custom web container and a database container directly from the docker hub. For development, my host directory is mounted in web docker, so I don't have to rebuild the container every time I make small changes. The web server is a Passenger (standalone) serving a ruby ​​application.

When I run it, I have my database running, my webservice running (on port 3000), all is well. However, if I make the changes, nothing changes as the web server (passenger) has to be restarted. I would like to be able to start a simple lightweight development server, for example thin

, which I would manually restart when I make a change.

What I have tried:

  • Starting a new web container ( docker-compose run web ...

    ) does not provide any port for the new container. Thus, I cannot connect to the webserver.
  • Starting a new web container with Docker directly ( docker run web -p 5000:5000 image_name ...

    ). We are losing docker compose functionality, the container is not database bound without manual bindings.
  • Re-doing the docker compose every time (as it starts quickly). Every time my database is reloaded so empty I need to keep working.
  • Use Argument --service-ports

    : Don't work as port 3000 is already in use
  • docker exec

    my dev server is in a web container: should be running on a different port, so won't show up.
  • docker exec

    kill

    my webserver: it actually works (restarts) but I don't really like this solution. First, since the server is still a Passenger, where would I prefer a lightweight web server (like thin

    ). Secondly, it is not very convenient for me to connect to the server using docker exec ...

    .
  • Modifying mine Dockerfile

    to replace Passenger by automatically restarting the dev webserver: I like it to Dockerfile

    be the same as prod, tests and dev.

Do you have a simple and easy way to start my web container with open port 5000 on which I would enable starting / restarting the dev webserver?

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I am using two files for docker compose, one for development and one for build.

In developing a docker compose file, you can override CMD

from your Dockerfile with command

so that you can easily use bash

to create a shell or use an automatic server restart.

To use a custom docker-compose file, follow these steps: docker-compose -f dev.yml ...



And for this:

Re-executing the docker compose every time (as it starts up). Every time my database is reloaded so empty I need to keep working.

If you do docker-compose up --no-deps web

it won't restart your db

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