Khanlou

While it’s a bit passé to not blog for over a year, and then dive right back in by talking about your blog setup, I’m going to do it anyway. I recently moved all of my static sites and Swift services over to Dokku, and I am really enjoying it.

Dokku is a collection of shell scripts that act as a self-hosted platform-as-a-service. Basically, it’s your own personal Heroku. Chris and I actually discussed it a few years ago on a (Patreon-only) episode of Fatal Error. I’ve wanted to move my stuff to it for a while, and finally spent some time over the break getting things moved over.

First, I want to run down how things were running before, and why I wanted something like Dokku. First, I manage 4 static sites, including this one. I, through painful trial/error/googling, carefully set up nginx virtual hosting to host all 4 sites on a single Linode instance. I also run 4 git remotes on that server, with clever post-receive hooks that accept pushes, do bundle install and jekyll build (when appropriate) and copy the HTML files to their final destination. This works pretty well and feels Heroku-esque (or Github pages-esque, if you like). I git push, and the rest happens for me automatically. I particularly like this model because it hits the trifecta — I get to host the site myself, I get to use Jekyll (including plugins!), and its interface is just a simple git push. I can even push changes from my phone using Working Copy.

Recently, I also started running a Swift API for a chore app for me and my girlfriend. I hope to blog more about this app soon for a few reasons, not least of which is that I wrote my own property wrapper-based web framework on top of Swift NIO, which has been working great.

This API has been running on Heroku. Because only two people use it, it doesn’t really make sense to pay $7/mo for a dyno, especially given that I run 4 static sites for $5/mo on Linode. Heroku does have a free tier they call “Hobby”, but using it incurs a performance penalty — your app spins down if you don’t use it for a little while (about 30 minutes or so?), and spinning back up takes 5-10 seconds. This makes for a pretty intolerable experience in the app. This too was a good candidate for moving to my own infrastructure.

I wrote one more small Swift-based web service for myself, which also shouldn’t have a ton of usage but does need its own Postgres database, and that cinched it. I wanted to move off of this patchwork system onto something more consistent.

I spun up a new Linode instance, installed Dokku, and got to work. Each Dokku site had three major components for me:

Buildpacks

Dokku uses buildpacks and Procfiles, just like Heroku, to describe how to install and run any app. Buildpacks can be set as an environment variable for the app, or included in the repo in a .buildpacks file. For Jekyll sites, you actually need two buildpacks:

https://github.com/heroku/heroku-buildpack-nginx.git
https://github.com/inket/dokku-buildpack-jekyll3-nginx.git

On the other hand, for Swift sites, the default Vapor buildpack works great:

https://github.com/vapor-community/heroku-buildpack

Encryption

Dokku has a concept of “plugins”, which add functionality to Dokku. The Let’s Encrypt plugin worked flawlessly for me. Installing a plugin is easy:

dokku plugin:install https://github.com/dokku/dokku-letsencrypt.git

You install it, set your email as an environment variable, and ask the plugin to add encryption to your site. (DNS for the relevant domains needs to be pointing at the server already for this to work.) Love it.

Databases

The two Swift services both need Postgres. No problem, just one more plugin:

dokku plugin:install https://github.com/dokku/dokku-postgres.git postgres

From the Postgres plugin, you can create databases, link them to apps, expose them to the internet, and manage them as needed.

Debugging

I want to end on one final note about debugging. Dokku itself is not a particularly complex tool, since it delegates all the isolation and actual deployment of code to Docker. (Side question: is it “dock-oo”, because of Docker, or doe-koo, like Heroku? The world may never know.) The reliance on Docker means that it can be really helpful to know how to debug Docker containers.

Two specific tips I have here:

1. You can dokku enter my-app-name web to enter the virtualized machine’s console, which can let you explore the structure of things.
2. You can use docker ps to list all the currently running containers, and use that to watch the logs of a build in progress, by using docker logs -f <container id>. This is super useful for debugging failing builds. (Big thanks to Sam Gross for giving me some insight here.)

Conclusion

Dokku basically checks all my boxes. I get to run things on my own servers, it’s cheap, and deploys are easy as a git push. I’m paying the same amount as before ($5/mo! I can hardly believe it!) My previously manually managed static sites all have the exact same interface as they used to, with a lot less work from me to set up and manage, and now I’m hosting Swift-backed sites as well. Put one in the W column.