Write your blog with Hakyll and Git

My home page and blog is written in Markdown and built with Hakyll. It’s hosted on a Linode VPS account and I update it with Git. Here’s how I do it.

Work locally

I have my local web site directory:

chris@chrisamilo:~/Projects/chrisdone-homepage$ ls
code  css  hakyll.hs  images  index.html  posts  posts.html  README
templates

Which is mostly stolen from Jasper Van der Jeugt’s Hakyll blog example

I work on it locally by building the Hakyll program:

chris@chrisamilo:~/Projects/chrisdone-homepage$ ghc --make hakyll
[1 of 1] Compiling Main             ( hakyll.hs, hakyll.o )
Linking hakyll ...

And previewing it locally:

chris@chrisamilo:~/Projects/chrisdone-homepage$ ./hakyll preview
Rendering _site/posts.html
Rendering _site/tags/blog.html
Rendering _site/tags/emacs.html
Rendering _site/tags/hakyll.html
Rendering _site/tags/haskell.html
Rendering _site/tags/twitter.html
Rendering _site/index.html
Rendering _site/posts/2010-04-04-tweet-your-haskell-errors.html
Rendering _site/posts/2010-04-04-hakyll-and-a-new-blog.html
Rendering _site/rss.xml
Starting hakyll server on port 8000...

hakyll preview watches your directories for changes and renders any updated files and saves them in the _site directory.

Push to remote

Once I’m happy with all my site/blog changes, I commit them:

chris@chrisamilo:~/Projects/chrisdone-homepage$ git commit -m "added code directory, post about tweeting your haskell errors"
[master 02bc308] added code directory, post about tweeting your haskell errors
 4 files changed, 166 insertions(+), 0 deletions(-)
 create mode 100644 code/haskell-tweet-errors.el
 create mode 100644 images/tweet-haskell-errors.png
 create mode 100644 posts/2010-04-04-tweet-your-haskell-errors.markdown
chris@chrisamilo:~/Projects/chrisdone-homepage$ git status
# On branch master
nothing to commit (working directory clean)

Then I (personally) push to github, just because I like looking at projects on Github.

chris@chrisamilo:~/Projects/chrisdone-homepage$ git push github
Counting objects: 18, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (13/13), done.
Writing objects: 100% (13/13), 34.59 KiB, done.
Total 13 (delta 3), reused 0 (delta 0)
To git@github.com:chrisdone/chrisdone-homepage.git
   62836bf..02bc308  master -> master

Finally I push to my Linode server, which pushes the commit, then runs the post-receive hook which recompiles the hakyll program, and runs ./hakyll build, which updates the changed files in the _site directory (which is really just a softlink to my /var/www/chrisdone.com directory.)

chris@chrisamilo:~/Projects/chrisdone-homepage$ git push linode
Counting objects: 18, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (13/13), done.
Writing objects: 100% (13/13), 34.59 KiB, done.
Total 13 (delta 3), reused 0 (delta 0)
[1 of 1] Compiling Main             ( hakyll.hs, hakyll.o )
Linking hakyll ...
Rendering _site/css/default.css
Rendering _site/images/tweet-haskell-errors.png
Rendering _site/code/haskell-tweet-errors.el
Rendering _site/posts.html
Rendering _site/tags/emacs.html
Rendering _site/tags/haskell.html
Rendering _site/tags/twitter.html
Rendering _site/index.html
Rendering _site/posts/2010-04-04-tweet-your-haskell-errors.html
Rendering _site/rss.xml
To chris@chrisdone.com:chrisdone-homepage.git
   62836bf..02bc308  master -> master
chris@chrisamilo:~/Projects/chrisdone-homepage$

And that’s it!

My configuration

.gitignore:

_cache
_site
*~
*.hi
*.o
hakyll

.git/config:

[remote "github"]
        url = git@github.com:chrisdone/chrisdone-homepage.git
        fetch = +refs/heads/*:refs/remotes/origin/*
        push = +master:refs/heads/master
[remote "linode"]
        url = chris@chrisdone.com:chrisdone-homepage.git
        push = +master:refs/heads/master

I never fetch from the Linode server, just push to it, so I don’t include a fetch configuration key.

The remote repository can just be empty:

$ mkdir chrisdone-homepage.git
$ cd chrisdone-homepage.git
$ git init
Initialized empty Git repository in /home/chris/chrisdone-homepage.git

And then in my chrisdone-homepage.git/.git/hooks/post-receive file:

#!/bin/sh
if [ -n $GIT_DIR ]; then
unset GIT_DIR
cd ..
fi
git checkout -f
ghc --make hakyll
./hakyll build

I had to look this one up. Git uses GIT_DIR to overwrite the current pwd, so you have to unset it, and the pwd starts as $YOURPROJECT/.git, so you have to cd ... Once that’s done you just git checkout -f, which does the following:

-f
    Proceed even if the index or the working tree differs from HEAD.
    This is used to throw away local changes.

Then we build hakyll and update the _site directory!