So my opinion, having worked in the space for years and the author of this post, is that the vast majority of people (engineers included) underestimate the sheer amount of work building a kernel that can run lots of applications on various clouds takes. Linux has been in development for ~30 years, Unix for 50.
That is to say it isn't necessarily lack of use-cases - it is ensuring you have enough support built for said use-cases when some user wants to use it. I'll give an example. Years ago people would say something like "I see you have GCP support - that's awesome - what about Azure?" Back then I'd say something like, well, give us a month cause we have to write new disk/network drivers but yes we can make that happen - a month is too long for that person though and so you immediately lose that person as a user/potential customer and have to wait until they come back. (We have great azure support now fyi.) Now take that same example and add it to every language, every cloud, etc. It's a ton of work.
Thanks for your perspective, and kudos on the article, impressive work!
So it is a matter of lack of support and general tooling around it. Anyone interested in the technology needs to write support for each individual tech stack and infrastructure to run it. The amount of complex work and the scarcity of people knowledgeable enough to do it is a huge hurdle.
Whereas Docker came around at a time when the low-level building blocks were already in place in Linux. Containers were already widely used in the industry, but each company had their own tooling around them. Docker made this technology much easier to use, which in turn helped define the standards that we use today.
So I'm still hopeful that something similar will happen eventually with unikernels. There's been a lot of work in improving the tooling around it, as your company has done, adding support for various tech stacks, optimizing hypervisors to run them efficiently, etc., so hopefully in a few years a tool that greatly improves the UX will be built, and an industry standard will emerge.
I think open source is a crucial part for this to happen. BTW, Nanos looks very cool!
That is to say it isn't necessarily lack of use-cases - it is ensuring you have enough support built for said use-cases when some user wants to use it. I'll give an example. Years ago people would say something like "I see you have GCP support - that's awesome - what about Azure?" Back then I'd say something like, well, give us a month cause we have to write new disk/network drivers but yes we can make that happen - a month is too long for that person though and so you immediately lose that person as a user/potential customer and have to wait until they come back. (We have great azure support now fyi.) Now take that same example and add it to every language, every cloud, etc. It's a ton of work.