But the process wasn’t perfect. My old blog engine was a bit forgiving about URLs. As long as the URL “slug” was correct, the URL could have any date in it. So there happened to be quite a few non-canonical URLs out in the wild.
And the 404 issues started to roll in. Great! So what do I do with those issues now? How do I fix them?
Here’s an example of my first attempt at front-matter for a blog post on my blog that contains a redirect.
--- title: "Localizing ASP.NET MVC Validation" permalink: /404.html date: 2009-12-07 -0800 disqus_identifier: 18664 redirect_from: "/archive/2009/12/12/localizing-aspnetmvc-validation.aspx" categories: [aspnetmvc localization validation] ---
As you can see, my old blog was an ASP.NET application so all the file extensions end with
.aspx. Unfortunately, this caused a problem. GitHub currently serves unknown extensions like this using the
application/octet-stream content type. So when someone visits the old URL using Google Chrome, instead of a redirect, they end up downloading the HTML for the redirect. It happens to work on Internet Explorer which I suspect does a bit of content sniffing.
It turns out, there’s an easy solution as suggested by @charliesome. If you add the
.html extension to a Jekyll URL, GitHub Pages will handle the omission of the extension just fine.
Thus, I fixed the redirect like so:
By doing so, a request for
https://haacked.com/archive/2009/12/12/localizing-aspnetmvc-validation.aspx is properly redirected. This is especially useful to know for those of you migrating from old blog engines that appended a file extension other than ``.html` to all post URLs.
Also, if you need to redirect multiple URLs, you can use a Jekyll array like so:
redirect_from: - "/archive/2012/04/15/The-Real-Pain-Of-Software-Development-2.aspx.aspx.html/" - "/archive/2012/04/15/The-Real-Pain-Of-Software-Development-2.aspx.html/"
Note that this isn’t just useful for blogs. If you have a documentation site and re-organize the content, use the
redirect_from plug-in to preserve the old URLs. Hope to see your content on GitHub Pages soon!