I’ve just recently been working on getting my Hexo blog set up, and importantly on getting it automatically deploy to Github Pages every time I do a commit. Given that this is a generated site, there are intermediate steps involved between the source that is committed and the site that is deployed.
The obvious way to achieve the actual Build part of this is to use the fantastic Travis CI, which can be set up to perform a build every time you do a commit to a Github Repository. The challenge involved in this is getting Travis to be able to push the deployed site back to Github for it to be accessed. However, it turns out that Github have a solution that can work for this as well.
From this point on, I’m going to assume that you’ve already got Hexo configured as you want it, and you know how to configure Travis to build a Github repository correctly.