Clarification on supported versions listed in README and relationship with nginx

[paba19]

Hello,

while tracking various software dependencies I noticed the table for supported versions in the main README and noted that there is a column in for "Nginx Version". I noticed also, that even the most recent version of the controller lists an nginx version that seems to have gone EOL already (1.21.6).

Is it possible to clarify in the README.md what is that column for?

Does it mean that ingress-nginx is using as a dependency a version of nginx that has gone EOL? Or it means that it has been tested with a configuration that is compatible with nginx 1.21.6?

Having gone through the code it would seem like it is the case of the former, but it would be good if you could clarify in the README as well.

Also, if you confirm that ingress-nginx is indeed using nginx 1.21.6, what is the policy for bumping the nginx version? When will it be bumped?

Thanks in advance

/kind documentation
/remove-kind bug

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[strongjz]

It means just that, you did point right that the version of nginx we use is here in our build script https://github.com/kubernetes/ingress-nginx/blob/main/images/nginx/rootfs/build.sh#L21

Supported is in the readme "Supported versions for the ingress-nginx project mean that we have completed E2E tests, and they are passing for the versions listed. Ingress-Nginx versions may work on older versions but the project does not make that guarantee."

The nginx base https://github.com/kubernetes/ingress-nginx/blob/main/NGINX_BASE is built with the image in https://github.com/kubernetes/ingress-nginx/tree/main/images/nginx

The nginx version itself gets updated when all the Lua modules in that same built script are supported by a new version of nginx. It takes time to build the nginx image, test all new deps, release a new base image, and update the build.

Nginx image update #9231

Base image update #9257

then release new image #9280

[balonik]

@strongjz is there any plan to update Nginx version? Last update was over a year ago. Are there any blockers to do it, because of unsupported LUA scripts?