It looks like others have had a similar idea, but just to publish its existence:
I’m using fleek.co for a test Hugo site of mine and the site required the hugo_extended image, which Fleek doesn’t provide. Also, they’re a bit lax in updating what they do have, so I decided to take their Dockerfile and modify it to provide recent hugo_extended images on their platform. The result is at Docker , with a repo available on that page . It works on Fleek, works for my needs in development. It’s not automated so it depends on me noticing a release announcement, but usually within a day I have the most recent release up. FWIW.