Since already some years, this site uses the Jekyll static site generator. Generating the complete site takes about 15 minutes. Some time ago, I decided to setup Gulp to minimize HTML in order to speed up page view for readers. This change added about 10 minutes to the build time, for a total of ~25 minutes, which is a long time…​ too long. I wanted to decrease the build time, so I decided to play around. The initial state A Docker image is used to build the site.

Last week, I wrote on how to design a generic Docker image for Maven-based auto-executable webapps. The designed build file has 3 different stages: checkout from Github, build with Maven and execute with Java. The Maven build stage takes quite a long time, mostly due to: Executing testsDownloading dependencies Tests can be executed earlier in the build chain - then skipped for Docker, this post will focus on speeding up the download of the dependencies. Let’s check each option in turn.