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

Question

I have a quite typical docker-compose setup: a custom web container and a database container directly from docker hub. For development, my host directory is mounted into the web docker so that I do not have to rebuild container each time I do a minor change. The web server is a Passenger (standalone) serving a ruby app.

When I run it, I have my database running, my web service running (on port 3000), all good. However, if I do a change, nothing changes as the web server (passenger) needs to be relaunched. I would like to have to be able to launch a simple lightweight development server such as thin that I would restart manually when I do a change.

What I tried:

Launching a new web container (docker-compose run web ...) does not expose any port for the new container. So, I cannot connect to the web server.
Launching a new web container with Docker directly (docker run web -p 5000:5000 image_name ...). We loose the docker-compose functionality, the container is not linked to the database without manual bindings.
Relaunching the docker-compose each time (as it starts quickly). Each time my database is relaunched so empty, I need to keep running.
Use --service-ports arg: do not work as port 3000 is already used
docker exec my dev server on the web container: has to run on another port, so will not be exposed.
docker exec the kill of my webserver: actually it works (it restarts), but I do not really like this solution. Firstly, because the server is still Passenger where I would prefer a lightweight web server (as thin). Secondly, I find it not very clean to connect to kill over and over the server with docker exec ....
Changing my Dockerfile to replace Passenger by an auto-relaunching dev web server: I like the Dockerfile to be the same as on the prod server, tests, and dev.

Would you have a clean and easy way of just launching my web container, with port 5000 open, on which I would a shell the launch/relaunch a dev web server ?

I've just moved all the source code into a data container that is exported using SMB to the developer. I wrote Docker Shell for this purpose - dockershell.io. — mzedeler
– mzedeler, Commented Jun 28, 2015 at 9:01

Charlie Egan · Accepted Answer · 2016-01-18 23:00:45Z

3

I use two docker-compose files, one for development and one for production.

In development the docker-compose file you can override the CMD from your Dockerfile with command so you can easily use bash to have a shell or use an auto relaunch server.

To use you custom docker-compose file do : docker-compose -f dev.yml ...

And for this :

Relaunching the docker-compose each time (as it starts quickly). Each time my database is relaunched so empty, I need to keep running.

If you do docker-compose up --no-deps web it will not relaunch your db

edited Jan 18, 2016 at 23:00

Charlie Egan

5,2637 gold badges36 silver badges53 bronze badges

answered Jun 4, 2015 at 14:28

Uhsac

8191 gold badge7 silver badges13 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

FabioCosta Over a year ago

So you are saying you run a docker compose with a database, and some dev server that just starts bash? Can you give a example of that ? I am seeking to start a mongo, a elasticsearch and a dev server without the server running (just bash it after the run)

Collectives™ on Stack Overflow

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

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related