Docker for Production

[lcreid]

Split from #23 . #23 had questions that apply more to a production deploy than to development use.

• How to deploy? You're supposed to deploy containers. Does it make sense to do a Capistrano deploy to a container? I suppose we could
• What's the model for static web sites? Do they get their own container? What does that container look like?
• How to manage the Nginx configuration files in staging and production? This may take us down the path of the Kubernetes-like tools -- yet another level of tooling
• Where do the Letsencrypt files go? And how to handle them?
• How to handle Redis? Can each application have its own Redis container, or is it easy to have one Redis for everyone (Redis doesn't really do great authentication if it faces a hostile world).

An "official" view of Rails on Docker: https://github.com/docker/labs/tree/master/developer-tools/ruby

[lcreid]

Random ideas:

One model is a collection of containers. One is the Nginx container. It talks to a volume that has the static files. Each application or site deploys its static files to its own directory in that volume. This is enough for a static site. It just deploys its files to its directory in the volume.

For a Rails app, its assets and other static files go to its directory on the volume. We probably need a public and private directory within the volume. The app is in its own container(s). The container has gems already bundled. I suspect that the bundle could also be pre-built and shared.

One difference from dev is that the database server is a real, separate service, not just another container. In other words, the database container is something added for development and local test.

So another real gap is how to put a new container into production? I suspect that this part is highly dependent on the target platform.

[lcreid]

Part of the complexity of the original set-up scripts, that turned into the small Ruby application, was that we have to set up an HTTP version of the site, then get the LetsEncrypt certificates, then switch to HTTPS. It looks like certbot can now modify the Nginx config automatically. You just run the certbot with an HTTP site and it becomes HTTPS. https://certbot.eff.org/docs/using.html#nginx

[lcreid]

A pretty thorough documentation of how to deploy containers to AWS ECS. Doesn't talk much about price, however: https://dev.to/farleyknight/how-to-deploy-a-rails-application-to-aws-with-docker-2fnc.