A Standalone Auth Framework for Happstack

It's been awhile since my series of posts outlining some of the basic ideas behind the HAppS Haskell web framework (which is since been renamed Happstack). Ever since I started developing it I envisioned a standalone library, perhaps shipped as a part of happstack, that would make it trivial for anyone to add robust authentication to their application. After doing some more work on Happs(tack) applications I've finally gotten around to working on the auth framework. I have created a github repository for the auth framework. It still needs a lot more work, but hopefully it will demonstrate some of the potential of Haskell and Happstack as a web development framework, and motivate some more improvement in this area. Comments, suggestions, or code contributions would be greatly apprectiated.

Comments

Post a Comment

Popular posts from this blog

Ember.js is driving me crazy

For the past few months I've been working on a project with a fairly complex interactive web interface. This required me to venture into the wild and unpredictable jungle of Javascript development. I was totally unprepared for what I would find. Soon after starting the project it became clear that just using JQuery would not be sufficient for my project. I needed a higher level Javascript framework. After a doing a little research I settled on Ember.js. The Zombie Code Apocalypse Ember was definitely a big improvement over straight JQuery, and allowed me to get some fairly complex UI behavior working very quickly. But recently I've run into some problems. The other day I had a UI widget defined like this: App.FooController = Ember.ObjectController.extend({ // ... }); App.FooView = Ember.View.extend({ // ... }); It was used somewhere on the page, but at some point I decided that the widget was no longer needed, so I commented out the widget's mar
Read more

Dependent Types are a Runtime Maybe

Awhile back I was discussing dependent types with someone and we ended up concluding that dependent types can always be replaced by a runtime Maybe.  This seemed to me then (and still does today) as a fairly surprising and provocative conclusion.  So I thought I'd put the idea out there and see what people think. Let's look at a few examples that are commonly used to illustrate dependent types: Vectors of length N Matrices of size m x n Sorted lists Height-balanced trees (trees where the height of subtrees differ by at most one) The argument is roughly as follows.  All of these examples ultimately boil down to enforcing some kind of constraint on some data types.  The more powerful your dependent type system, the more rich and expressive will be the constraints that you can enforce.  If we take this thought experiment to its logical conclusion, we end up with a dependent type system that allows us to enforce any constraint that can be computed. The important realization here is
Read more

Setting Up A Private Nix Cache

I recently went through the process of setting up a private Nix binary cache. It was not obvious to me how to go about it at first, so I thought I would document what I did here. There are a few different ways of going about this that might be appropriate in one situation or another, but I’ll just describe the one I ended up using. I need to serve a cache for proprietary code, so I ended up using a cache served via SSH. Setting up the server For my cache server I’m using an Amazon EC2 instance with NixOS. It’s pretty easy to create these using the public NixOS 18.03 AMI. I ended up using a t2.medium with 1 TB of storage, but the jury is still out on the ideal tradeoff of specs and cost for our purposes. YMMV. The NixOS AMI puts the SSH credentials in the root user, so log in like this: ssh -i /path/to/your/key.pem root@nixcache.example.com To get your new NixOS machine working as an SSH binary cache there are two things you need to do: generate a signing key and turn on cache serv
Read more