Generating OG images in Elixir

I recently added per-page OG images to this blog and it was less complicated than I expected. On top of that, I was able to completely stay within the Elixir ecosystem! If you’re not familiar, OpenGraph image meta tags let you define an image that should be rendered as a preview for the page, which is used in social media and messaging apps. So let’s start with the requirements: I wanted a low effort approach to creating per blog post OG images, and that new posts should automatically get images without any additional work. Additionally, I wanted matching images for pages like /about. I’m using NimblePublisher to render markdown to HTML at build time and I wanted to follow the same principle for the OG images. Image library Step one was figuring out how to generate these images on the fly. The JS community has takumi-js and satori that take a basic HTML template and render it to an SVG/PNG using the Yoga layout engine. This is very convenient because you can write a HTML/CSS and get…