NGINX ABI compatibility

[dvershinin]

Hi,

Are you going to keep the ABI compatibility between NGINX and Angie?

E.g. from the latest release:

Feature: all functionality of nginx 1.23.3.

Does this mean dynamic modules compiled using --with-compat against NGINX 1.23.3 would work with that Angie release without problems?

[VBart]

Hi,

Unfortunately, it's not practically possible to maintain ABI compatibility between Angie and nginx for the same reasons as there's no ABI compatibility even between two minor versions of nginx (like nginx 1.23.2 and 1.23.3).

Any bugfix or even small feature can easily (and sometimes unintentionally) alter ABI in nginx, not to mention rich feature set implemented in Angie and planned.

The --with-compat flag doesn't help here as its purpose to maintain ABI compatibility between nginx open-source builds and related commercial versions. In order to make it work also for Angie, we need to add relevant changes and specific placeholders to nginx source code, which isn't under our control.

So, we had to drop the idea of trying to maintain such compatibility and added special check that prevents loading modules compiled for nginx into Angie. Those modules need to be recompiled for Angie.

We do our best-effort to maintain API compatibility, but as more features and improvements we will add, then more likely it can be lost at some point.