A Directory of Open Source Clojure Projects

Every now and again I'll come across a post where someone asks about getting involved in open source clojure projects. Because every question deserves a single-page app dedicated to its answer, I made Open Source Clojure Projects, a directory of active projects welcoming new contributors.

Each project has (or should have) clear instructions on:

Developing the project locally

Running tests if there are tests

Contributing code (pull request? tests required?)

Contacting other devs - slack, mailing list, IRC, etc

Also, there's a "beginner-friendly" flag so that new Clojurists can easily find projects with tasks that are appropriate for their skill level.

So far, 22 projects have been added, which is awesome. A random sampling:

milestones, which generates the best possible schedule from a set of tasks

reverie, a CMS for power users

Scheje, a little Scheme on Top of Clojure (!!!)

system, a friendly layer on top of Stuart Sierra's component library

If you have an open source project and want people to contribute, please add it!

The Stack

A few folks have asked me about what tools I used to create the site. I'll explain more below but briefly:

The backend is a weird, unholy mess of fantastic classic libraries and sideshow code that I keep transplanting from one project to another so that I can answer the question what kind of abomination will this morph into this time?. The backend uses Github as a database, though, and that's pretty neat.

The frontend uses re-frame and includes some form handling code that I'm proud of and that's actually worth stealing.

Finally, there's also some code for deploying with Ansible that's worth stealing.

In the time-honored fashion of technical blog posts everywhere, I'll now "dive in" and elaborate on each of those bullet points.

Backend

For the backend, the site uses ring, compojure, liberator, http-kit, and the weird set of tools that have accreted in my projects over the years. Even though the code footprint for the backend is pretty small, it's pretty idiosyncratic, containing handfuls of half-formed ideas I keep noodling around with. Hopefully someday soon I'll be able to really nail down my approach to backend dev and share it, because it does allow me to write apps quickly.

One cool part of the site is that it uses a Github repo, Open Source Projects, as its database. Browse the projects directory and you can see every project that's listed on the site stored as an EDN file. When the backend starts up it reads from Github, and whenever someone posts or edits a listing it writes the EDN file using Github's API.

The nice thing about this approach is that I didn't have to worry about standing up a server or keeping backups. And it was just fun to code. Here's the source for using Github as a db - I definitely see potential in reusing this approach for similar lightweight directory sites.

Frontend

re-frame has a delightful README that gracefully introduces you to reactive programming. If you haven't read it then stop reading this article and read that instead; I am 100% confident that it's a better use of your time.

re-frame is a joy to use, and it's become my go-to tool for frontend projects. I've written a fair amount of code for working with forms and submitting values. This code forms a kind of nano-framework on top of re-frame, and it's allowed me to speed up the development process from project to project. Here's an example form which uses the form helpers. If you'd like for me to write a detailed explanation of this code, please leave a comment letting me know :)

Boot deserves a special mention because it makes it so easy to develop ClojureScript apps. With Boot you get live reload (every time you change your frontend files, the changes are automatically injected into the browser), giving you a near-instantaneous feedback cycle that makes development much more enjoyable. It's also easy to incorporate Sass compilation - and your Sass files also get the live reload treatment.

If you're not using Boot to build your ClojureScript app then chances are you're causing yourself undue suffering. And hey, maybe you're into that? No judgment. But if you're not, then take the time to learn it - it's a great investment in yourself as a Clojure developer.

Deployment

The infrastructure directory contains scripts for provisioning and deploying to a server with Ansible. It also has a Vagrantfile so that you can stand up a test server locally; just run vagrant up to both create the virtual machine and provision it. To deploy, cd into the infrastructure directory and run ./build.sh && ./deploy-dev.sh . Those two shell scripts are extemely simple, so take a look at them to see what's involved in deployment.

The Ansible configuration is almost completely reusable. You can check it out in infrastructure/ansible . The roles directory in particular has Ansible tasks for creating an nginx server that can run Clojure app. It also includes an Upstart script for controlling startup/shutdown of your Clojure app (assuming you use Ubuntu).

The Future

Eventually, I'd like to add more tools for project discovery and for showing project stats. @yogthos, for example, suggested incorporating a project's stats from github so that users can see how active and popular each project is, information that can help them decide which project to contribute to.

Also, I'm in the process of revamping braveclojure.com to include more resources for Clojure programmers. The site hovers around 3rd or 4th Google result for "Clojure", just below clojure.org and the Wikipedia entry. So, it's kind of popular I guess. My hope is that by featuring Open Source Clojure Projects, I'll help more new developers get involved and also help project maintainers squash some tickets.

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