/var/blog

by Marshall Pierce

Blogging With Grain and S3

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I prefer static site generators when it comes to blogging: they're easy to store in version control, and they're pretty bulletproof security-wise. I'd used Octopress before, as well as plain Jekyll, and though I liked the concept, in practice neither worked smoothly: the whole gem infrastructure is kinda messy, and "watch for changes" mode didn't work reliably. So, when I saw a blurb about Grain, a static site generator written in Groovy, I investigated and was pleased to see that it (1) had an Octopress theme clone for easy blog setup, (2) was written with (IMO) best-in-class tech choices: Groovy, Guice, and Gradle, and (3) had watch-for-changes that actually worked.

Grain

This blog uses the Octopress theme for Grain. I chose to fork (see the varblog branch) the main octopress theme repo so that I could more easily incorporate future improvements, rather than starting a new repo using a released version. Especially as Grain matures, you may wish to just take a released version and go from there, but for now using a fork has been fine, and it's let me easily make pull requests as I make improvements that could be generally useful to other users.

I encourage interested readers to go look at the commits in my fork to see all the setup steps I took, but I'll point out one in particular. My Linux system used Python 3 by default, which wasn't compatible with the version of Pygments bundled with Grain. So, to change it to look for python 2 first, I added the following to my SiteConfig in the features section:

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    python {
        cmd_candidates = ['python2']
    }

S3 Hosting

Hosting static output in S3 is pretty common. The speed and reliability of S3 is tough to beat, and even though it's non-free, for most people hosting a blog on S3 will cost less than $1 a month.

I first created an S3 bucket named the same thing as the domain (varblog.org). I enabled static website hosting for the bucket (using index.html as the index document) and set the bucket policy to allow GetObject on every object:

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{
    "Version":   "2008-10-17",
    "Id":        "Policy1388973900126",
    "Statement": [
        {
            "Sid":       "Stmt1388973897544",
            "Effect":    "Allow",
            "Principal": {
                "AWS": "*"
            },
            "Action":    "s3:GetObject",
            "Resource":  "arn:aws:s3:::varblog.org/*"
        }
    ]
}

I made a Route 53 hosted zone for varblog.org (remember to change your domain's nameservers to be Route 53's nameservers) and set up an alias record for varblog.org to point to the S3 bucket.

Uploading to S3

I created a dedicated IAM user for managing the bucket and gave it this IAM policy:

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{
    "Version":   "2012-10-17",
    "Statement": [
        {
            "Sid":      "Stmt1388973098000",
            "Effect":   "Allow",
            "Action":   [
                "s3:*"
            ],
            "Resource": [
                "arn:aws:s3:::varblog.org/*"
            ]
        },
        {
            "Sid":      "Stmt1388973135000",
            "Effect":   "Allow",
            "Action":   [
                "s3:*"
            ],
            "Resource": [
                "arn:aws:s3:::varblog.org"
            ]
        }
    ]
}

This allows that user to do everything to the varblog.org bucket and its contents, but not to do any other AWS actions. I created an Access Key for the user in the IAM console and used it to configure s3cmd with s3cmd --configure -c ~/.s3cfg-varblog.org. This creates a separate config file which I then reference in the s3_deploy_cmd in SiteConfig.groovy. This way, even though I'm storing an access key & secret unencrypted on the filesystem, the credentials only have limited AWS privileges, and I'm not conflating this s3cmd configuration with other configurations I have. Note that when configuring s3cmd, it will ask if you want to test the configuration. Don't bother, as this test will fail: it tries to list all buckets, but this isn't allowed in the IAM user's policy.

At this point, ./grainw deploy will populate the bucket with the generated contents of the site.

Other stuff

For Google Analytics and Disqus I simply created new sites and plugged in the appropriate ids in SiteConfig. I chose to update the GA snippet template since by default new GA accounts use the "universal" tracker which has a different snippet than good old ga.js. If your GA account is old-school, you should be able to leave the template as-is.

Other than that, all I did was tweak some SASS in theme/sass/custom.

What's with the name?

If you're not a Linux/Unix user, this blog's name will make no sense. Then again, the rest of this post probably didn't either. The /var/log directory is historically where log files have gone on Unix-y systems, and 'blog' is kind of like 'log'. Or, put another way, I thought it was amusing when I registered this domain long, long ago.

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