I would love to hear you overall review of everything. I'm really into all the options. Dokku seems too simple for the stuff I want to do. Flynn is pretty awesome, but I've been loving the steady progress Deis makes. Rancher is also interesting.
I'd love to know what was the smoothest process for something like a phoenix/node/rails app out of these. Feel free to email me at jbhatab@gmail.com if you feel like breaking it down over chat too :D
I'm going to write a three-part blog posts that discusses the strengths and weaknesses of each system. I'll email you when I'm done.
We use Cloud Foundry in production and we've used Dokku in development. CF is similar to Dokku and Flynn as it can provide services (databases etc) and wire them to your container.
Everyone running hobby projects should be using Dokku. It's very easy to get started and can replace Heroku in many cases. It is missing HA but you can always scale horizontally or load balance multiple dokku nodes (behind say nginx/haproxy) against an external db/redis although you are essentially running commands for each node.
Dokku should look into Docker Swarm to do orchestration but that is a mammoth task for a pure open source project (no support business to fund it) and as josegonzalez mentions he needs the cash to be motivated to do it. Dokku also lacks a stable way to ship logs to external services. dokku-logspout is available as a plugin but it frequently loses it's connection and needs to restart. But then excels past any of the other PaaS solutions when it comes to SSL integration via Let's Encrypt. It's a truly remarkable project.
Flynn provides services and sets up Postgres to balance between nodes so it too is HA. Flynn works with Google, Amazon and Digital Ocean via it's web installer (I had trouble getting it to run on a third-party provider, SSH was broken). Flynn provides Postgres, redis, MySQL and MongoDB out of the box and HA but with the caveat that you can't really customize these services. I also killed one of the three nodes via the DO console and it still carried on with no issues.
Deis was the hardest of the bunch. It essential is a manual process to get Kubernetes up and running unless you use the cozy Google Cloud Container which I did but isn't cheap ($100/month before bandwidth for 2 containers). Once up and running it is as easy as the other two. They don't have any services though - people suggested running either running Postgres in a container. I think a PaaS should include the DB but that's debatable.
Things I haven't tried:
- adding a node to Flynn or Deis once up and running
- killing a node on Deis and checking if it still runs (I assume Kubernetes takes care of this)
- incorporating these systems with Gitlab to provide a full continuous delivery system
Dokku + Swarm actually isn't too hard (at least old swarm). I wrote a prototype in ~10 lines of code changes this past summer.
As far as shipping logs, I feel as though thats the responsibility of the underlying container environment, and so I'd probably have something that is based on setting docker options for containers (or an interface to do that for whatever scheduler you are using).
Just curious, outside of multi-host support - I'm not in the business of writing a scheduler, so we'll most certainly use an existing one if we ever get to this feature - what is too simple about Dokku?
I'd love to know what was the smoothest process for something like a phoenix/node/rails app out of these. Feel free to email me at jbhatab@gmail.com if you feel like breaking it down over chat too :D