feat(library) -> add nginx 1.31

[vTusharr]

Adds an nginx 1.31.0 image based on alpine as a base , modelled on the existing 1.25 image.
circumventing CVE which is present in earlier version

[Copilot]

Pull request overview

Adds a new Unikraft library image definition for unikraft.org/nginx:1.31, intended to provide an updated Nginx base (Alpine-based) and address the CVE mentioned in the PR description.

Changes:

• Introduces a new library/nginx/1.31 image definition (Kraftfile + scratch rootfs Dockerfile).
• Adds a custom Nginx configuration (single-process, tokens off, gzip, basic security headers).
• Adds the default Nginx welcome page and a versioned README for running the image.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
library/nginx/1.31/wwwroot/index.html	Adds the default Nginx welcome page content.
library/nginx/1.31/README.md	Documents how to run/query the new unikraft.org/nginx:1.31 image.
library/nginx/1.31/Kraftfile	Defines the Unikraft build configuration and lwIP settings for Nginx 1.31.
library/nginx/1.31/Dockerfile	Builds a minimal scratch rootfs by copying Nginx + runtime deps from nginx:1.31.0-alpine.
library/nginx/1.31/conf/nginx.conf	Adds the Nginx runtime configuration for the image.

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[razvanvirtan]

@vTusharr What is the reasoning for adding this limit, is it something enforced by the new version of nginx?

[vTusharr]

Ah no , its not required by this version of nginx .
The limit came from a common nginx tuning guideline , most production configs recommend setting it to at least worker_processes * worker_connections * 2 + 100 fd tho libposix_fdtab_maxfds have it default @ 1024

[vTusharr]

So i think we can either drop this [but i am not sure how will runtime will react when it runs out of fdtabs ]
or like add a comment to kraftfile indicating for libposix_fdtab_maxfds so one can change it to their needs

[razvanvirtan]

I think it is fine to drop this in the standard config. If I understand that config option correctly, with no explicit value set, the process will only be limited by the open fds limit on the OS, which is something to be configured outside of the nginx config.

[razvanvirtan]

Still waiting for WASP permissions to start the testing. @vTusharr In the meantime, please fix the issues mentioned by Copilot. Also, see my follow-up comment.

[razvanvirtan]

@vTusharr What is the reasoning for adding this limit, is it something enforced by the new version of nginx?

[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

[vTusharr]

I think thats debian base specific , @razvanvirtan ?

[razvanvirtan]

It looks like it works even without that. Still, one last question before merging: why using the alpine image instead of the bookworm one? If no significant reason, I would switch to bookworm, to keep this uniform with the nginx 1.25 port

[vTusharr]

Ah ok so first i had tried the official image which now no longer ships with bookworm but with trixie which i think have updated glibc and was crashing so it led me to musl based alphine
One thing we can do is use bookworm as a base and build the binary then use that .

[razvanvirtan]

We should be good with alpine as well, just wanted to check we have a reason for it 👍

[vTusharr]

valid

[razvanvirtan]

Thanks @vTusharr!