Metalsmith Static Site on Azure

I enjoy reading blogs, and I’ve always wanted one of my own. However, I had a short set of requirements that I wanted to satisfy with any solution I came up with:

  • Markdown support (plus some useful extensions)
  • Mobile support (at least iPad)
  • Easy photo integration
  • Perhaps IPython integration

I quickly found the Ghost platform (and app) which is an incredibly cool bit of technology. I really liked the ability to create and edit in Markdown in a browser app. Adding a photo inline is incredibly easy to do, and there are some nice themes. I played around with Ghost until my 14-day trial period came to an end. I was nearly hooked, but in the end I thought that 29 USD / month was too steep a price for just one blog. So I looked elsewhere.

An Azure Sky

I used to work at Skype (Microsoft), and I was and still am really impressed with Microsoft’s Azure service. I decided to see if I could use Azure to host my site. There are variety of hosting options available, but the simplist is just a stock Azure Web app. A big feature of this setup is that one can allow updates to the web content via Git. Thus, a reasonable workflow becomes:

  • Update blog content
  • Commit changes to local Git repository
  • Push changes to Azure remote Git repository

With the last step, Azure will do whatever is necessary to incorporate the changes from Git, including restarting the IIS server when there are configuration changes in the web.config file – which is necessary when adding additional media MIME types.

Static Cling

Using the above work flow, I could craft my own HTML pages and be done, but I’ve been there back in Netscape days, and I’m not interested in doing that again. I’d rather do some version of Markdown in a text editor such as Emacs, and then run some kind of conversion process to generate the HTML pages. Also, I did not want to do the conversion upon each request on the Azure server – instead, I should be able to do the conversion away from the server, and then add the converted output to the Azure web server.

Thus, I wanted a static site generator. I began looking at various static site generators (see https://www.staticgen.com for a good place to start), focusing on the scripting languages I already knew (Javascript and Python). I evaluated several, and I was close to going with Nikola but in the end I went with Metalsmith for reasons I can no longer recall.

Metalsmith

In brief, Metalsmith is a pipeline processor which takes in a set of files, pushes them through one or more user-defined processing steps, resulting in (hopefully) a set of HTML and media files (pictures, movies, etc.). The input files can be anything, really: the default action is to copy them to a destination directory. There are various canned Metalsmith processors available on the Metalsmith site (scroll down), and additional ones can also be found on NPM – just search for metalsmith.

The processing chain I came up with is a mixture of canned processors plus some custom (inline) processors I created to do things they way I thought made sense. The whole beautiful mess is available on my GitHub site, where I also take a stab at documenting the processing flow. So far, the flow makes sense and does everything I want the way I want it. I especially like to IPython support using notebookjs and the inline math rendering obtained through KaTeX. Both highly recommended.

Workflow

To post a new blog item, I create a new directory under src/articles and drop a new index.md file into the new directory. This will hold the Markdown content of the new post. Each file starts with a header such as below (taken from this very post):

---
title: Metalsmith Static Site on Azure
description: Where I describe how I use Metalsmith to run a static site blog on Azure
date: 2016-08-30 09:56:02+02:00
author: Brad Howes
tags: Javascript, Metalsmith, Markdown, Azure
layout: post.hbs
image: computer-keyboard-stones-on-grass-background-header.jpg
---

The title is what appears at the top of the post and in post listings. The description content supposedly describes what the post is about – it is shown below the title in all pages except for the post itself. Scroll to the bottom of this page to see what I mean.

I think date and author are self-explanatory. I can add or more tags to the tags header which allows grouping posts by their tag values. Note that on the site, I confusingly refer to these as “topics” but not consistently – I should fix that. Next, layout says which Handlebar template to use for rendering into HTML. Finally, the image header identifies an image to show as a banner across the top of the blog post, above the title.

Below the metadata header comes the contents of the post.

If I am on my laptop, I can easily preview the post after each save of the index.md file by running the following in the top-level of the blog’s repository:

% node build

This will create a simple web server that is running on localhost:7000 with the feature of rebuilding the site when a file changes. NOTE: this is different than the stock Metalsmith behavior which tries to only reprocess the file that changed. I was unable to get some changes to cause a proper reprocess so I wrote my own file watcher and reprocessor and just regenerate the whole site when any file changes. Expensive but simple.

Saving and Deploying

When I’m satisfied with the blog post, I can add the new file(s) to the local repository, commit them, and then push the changes to GitHub.

% cd ~/src/keystrokecountdown
% git add src/articles/newpost
% git commit -am 'New post'
% git push

To deploy the new blog post to my Azure web site, I have to do basically the same, but from the site’s deployment directory:

% cd ~/Sites/keystrokecountdown
% git add src/articles/newpost
% git commit -am 'New post'
% git push

That last step will cause my Azure Web service to deploy the new content. These steps are fairly easy to automate via a Bash script or function which just takes in a post directory name and a comment:

#!/bin/bash
DIR="${1}"
shift 1
COMMENT="${@}"
cd ${HOME}/src/keystrokecountdown || { echo "*** missing source repository"; exit 1 }
git add src/articles/${DIR} || { echo "*** failed to add '${DIR}' to source repository"; exit 1 }
git commit -am "${COMMENT}" || { echo "*** failed to commit changes to source repository"; exit 1 }
git push || { echo "*** failed to push changes to GitHub"; exit 1 }

cd ${HOME}/Sites/keystrokecountdown || { echo "*** missing site repository"; exit 1 }
git add articles/${DIR} || { echo "*** failed to add ${DIR}' to site repository"; exit 1 }
git commit -am "${COMMENT}" || { echo "*** failed to commit changes to site repository"; exit 1 }
git push || { echo "*** failed to push changes to Azure"; exit 1 }

Not too shabby…

Serving Static Media using IIS

As I mentioned above, one must muck with a web.config file when serving anything other than HTML and image files. For instance, my site uses some free fonts which have the .woff or .woff2 extension. To allow these, and to pass them with the right MIME type header, the following must be part of the src/web.config file in the blog source repository (which is just web.config in the Azure site’s repository):

<?xml version="1.0" encoding="utf-8" ?> <!-- -*- Mode: xml -*- -->
<configuration>
  <system.webServer>
    <staticContent>
      <remove fileExtension=".woff" /> <!-- In case IIS already has this mime type -->
      <mimeMap fileExtension=".woff" mimeType="application/x-font-woff" />
      <remove fileExtension=".woff2" /> <!-- In case IIS already has this mime type -->
      <mimeMap fileExtension=".woff2" mimeType="application/x-font-woff" />
    </staticContent>    
  </system.webServer>
</configuration>

Furthermore, I want to support RSS feeds, which requires allowing XML responses from an RSS query, I need to amend the above with the following snippet:

<remove fileExtension=".xml" /> <!-- In case IIS already has this mime type -->
<mimeMap fileExtension=".xml" mimeType="application/rss+xml" />

Finally, if I want to serve a video file with an .m4v or .mp4 extension, I need the following entries:

<remove fileExtension=".m4v" /> <!-- In case IIS already has this mime type -->
<mimeMap fileExtension=".m4v" mimeType="video/mp4" />
<remove fileExtension=".mp4" /> <!-- In case IIS already has this mime type -->
<mimeMap fileExtension=".mp4" mimeType="video/mp4" />

That’s is it so far. To see a blog post with an embedded movie, go here.