Support other OIDC providers

[etiennej70]

Support other OIDC providers

Summary

URL check performed for discovery URL is too restrictive and can only be compatible with keycloack products. It should be possible to configure other OIDC providers.

Why?

Not using keycloack provider.

How

Modify check on discovery-url in pkg/config/config.go

Currently it is :

func (r *Config) extractDiscoveryURIComponents() error {
	reg := regexp.MustCompile(
		`(?P<legacy>(/auth){0,1})/realms/(?P<realm>[^/]+)(/{0,1}).*`,
	)

	matches := reg.FindStringSubmatch(r.DiscoveryURI.Path)

	if len(matches) == 0 {
		return apperrors.ErrBadDiscoveryURIFormat
	}

	legacyIndex := reg.SubexpIndex("legacy")
	realmIndex := reg.SubexpIndex("realm")

	if matches[legacyIndex] != "" {
		r.IsDiscoverURILegacy = true
	}

	r.Realm = matches[realmIndex]
	return nil
}

Can be modify by inserting directly the /.well-known/openid-configuration in the discovery-url parameter

Acceptance criteria

Be able to use another OIDC provider (google, ping federate, 0Auth, ...)

Additional Information

N/A

[p53]

hi, we already has this request here several times, if we would like to support also other IDP providers it is not just about changing this url, we would need to restrict/remove also other features/refactor/test code to be able to fit also for other providers, so it is not just about changing this one thing it is whole more complex thing. I already tried it with google, that maybe seems good candidate for next provider and i have idea maybe how to do it in a way that would scale but in short term i don't think more providers will be supported (depends on how much time i will have)