If Nginx+Lua had better development and testing support (back in 2016, I haven't really looked at it in a while) we might have gone that way.
It was kinda "here's a script, load it on nginx and hope it works" so it required a considerable amount of work to make it reliable and testable. Golang actually has a lot of stuff already done for you in terms of proxying so that part of the gateway isn't really that large.
There was no simple way to reload configs on the fly (other than updating the file locally with something like chef or ansible and reloading nginx on all machines) and that made it harder to provide self service routes from the get go (it's much easier nowadays with Nginx Service Mesh).
Nowadays with the options available I don't think we'd build it from scratch anymore (we could even use Zuul 2 I think). I'd say our mistake was that we didn't open source it in the beginning to benefit from more external usage and contributions, the way it is tied to internal services nowadays makes this hard to pull off right now.
It was kinda "here's a script, load it on nginx and hope it works" so it required a considerable amount of work to make it reliable and testable. Golang actually has a lot of stuff already done for you in terms of proxying so that part of the gateway isn't really that large.
There was no simple way to reload configs on the fly (other than updating the file locally with something like chef or ansible and reloading nginx on all machines) and that made it harder to provide self service routes from the get go (it's much easier nowadays with Nginx Service Mesh).
Nowadays with the options available I don't think we'd build it from scratch anymore (we could even use Zuul 2 I think). I'd say our mistake was that we didn't open source it in the beginning to benefit from more external usage and contributions, the way it is tied to internal services nowadays makes this hard to pull off right now.