Use NGINX Go Parser to generate configs

[rikatz]

Today we do some fancy template replacements, generating our config and sometimes failing at it.

F5 has a port of their crossplane library to Go: https://github.com/nginxinc/nginx-go-crossplane/tree/main

We can think on replacing that template generator for this library, so we can even marshall/unmarshall and compare structs when we need to reconfigure something, as an example.

This may also allow us to escape some directive configs, and when generating the configuration, things like quotes, {}, etc will be escaped by this parser

[rikatz]

/triage accepted

[rikatz]

Some proposed tests that we need to do:

• Pick an nginx.conf file generated by controller
• Unmarshall it to a structure as this library does
• Encode it again using this same library
• See if the generated file is the same as before and if it is still working
• Report back on that issue :slightly_smiling_face:
• Try, using this library only, to create a config file that looks like an ingress-nginx config file
• Report back to us again
• Tell me your thoughts on using this instead of go template, including the fact that if we go to this library, users won’t be able to change nginx.tmpl anymore
• Try passing bad values that we know people been trying to escape ngionx (like something”; load_by_lua bla) as part of the struct and see what happens
• Check if on template.go (the last step) we can use this as our template generator, getting the bytes buffer generated by the template, passing to this library, unmarshal and remarshall but trying to split new “server” directives per file

[rikatz]

Started to test here using benchmark, but already got stuck on the fact that the parser skips directives it doesn't understand.

lua_package_path for instance is not recognized and skipped, then parsing fails.

So while we use outside directives, it won't be able to use it. Maybe once the parser supports additional directives configurations we can come back to it

/lifecycle frozen

[k8s-triage-robot]

This issue has not been updated in over 1 year, and should be re-triaged.

You can:

• Confirm that this issue is still relevant with /triage accepted (org members only)
• Close this issue with /close

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/remove-triage accepted

[grounded042]

One thing to consider as this work is being done is that currently the docs call out the ability to customize the nginx.conf template: https://kubernetes.github.io/ingress-nginx/user-guide/nginx-configuration/custom-template/