Saturday, 14th October 2017
Back in 2008 Natalie Downe and I deployed what today we would call a microservice: json-head, a tiny Google App Engine app that allowed you to make an HTTP head request against a URL and get back the HTTP headers as JSON. One of our initial use-scase for this was Natalie’s addSizes.js, an unobtrusive jQuery script that could annotate links to PDFs and other large files with their corresponding file size pulled from the
Content-Length header. Another potential use-case is detecting broken links, since the API can be used to spot 404 status codes (as in this example).