fix: discover mounted geoip db files

[kd7lxl]

The docs say:

it is possible to use a volume to mount the files /etc/nginx/geoip/GeoLite2-City.mmdb and /etc/nginx/geoip/GeoLite2-ASN.mmdb, avoiding the overhead of the download.

however, this was not possible because the config only iterated over downloaded geoip db files:

ingress-nginx/rootfs/etc/nginx/template/nginx.tmpl

Line 177 in 93070fa

{{ range $index, $file := $all.MaxmindEditionFiles }}

MaxmindEditionFiles is only set in DownloadGeoLite2DB():

ingress-nginx/internal/nginx/maxmind.go

Lines 61 to 72 in 93070fa

	// DownloadGeoLite2DB downloads the required databases by the
	// GeoIP2 NGINX module using a license key from MaxMind.
	func DownloadGeoLite2DB() error {
	for _, dbName := range strings.Split(MaxmindEditionIDs, ",") {
	err := downloadDatabase(dbName)
	if err != nil {
	return err
	}
	MaxmindEditionFiles = append(MaxmindEditionFiles, dbName+dbExtension)
	}
	return nil
	}

What this PR does / why we need it:

This PR fixes #6012 by initializing nginx.MaxmindEditionFiles with the files in /etc/nginx/geoip.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Which issue/s this PR fixes

fixes #6012

How Has This Been Tested?

New e2e test case included in PR asserts that an existing GeoIP db file is loaded and results in the geoip2 section being included in the config.

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have added tests to cover my changes.
• All new and existing tests passed.

[k8s-ci-robot]

Hi @kd7lxl. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[rikatz]

/ok-to-test

[strongjz]

should we return a nil config here? , also shouldn't we log the errr inline #311

[kd7lxl]

To preserve existing behavior, errors are ignored and handled later by disabling geoip2 support. Returning a nil config would be a breaking change to any users expecting the existing behavior. My intent with this PR is to fix the feature without any breaking changes.

ingress-nginx/internal/ingress/controller/store/store.go

Lines 885 to 887 in 78afe7e

	if s.backendConfig.UseGeoIP2 && !nginx.GeoLite2DBExists() {
	klog.Warning("The GeoIP2 feature is enabled but the databases are missing. Disabling")
	s.backendConfig.UseGeoIP2 = false

I'm not sure why this behavior was chosen initially -- personally I would prefer it to return a nil config so it's easier for an operator to identify problems with the geoip2 download.

[strongjz]

Agreed, I reviewed master and realized it was the same.

[strongjz]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: kd7lxl, strongjz

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