... and then you're done. Of course, we have a CI server that builds our packages regularly, so it's likely you wouldn't even need to build from source (though you certainly could, if desired).
It is better to run components in separate containers instead of one container that runs everything together. You'll likely have a single proxy but multiple copies of application. Also, you don't need to deal with getting Envoy and Python application built together, or even care about how the Envoy image is built since you can use the provided one.
A big list of libraries one has to install is kind of intimidating, yeah. But them's the breaks.
What seems particularly offensive to me is that it declares that it specifically requires GCC 4.9. I'm really not OK pinning your brand new impressive world changing open source cloud technology to a compiler release series that's 3.5 years old. It looks either staid, or uncaring, or otherwise dull to have slipped to far behind the times, and it's intimidating to think the codebase is complex enough C or C++ that it really matters a whole lot.
That nets you
... and then you're done. Of course, we have a CI server that builds our packages regularly, so it's likely you wouldn't even need to build from source (though you certainly could, if desired).