Implement Environment variable configuration through `Env:` fields for grafana deployments

[hubeadmin]

Is your feature request related to a problem? Please describe. Currently, the operator has the option to pass environment variables to the grafana deployment through envFrom which can parse configMaps and Secrets for Env Vars located in them, this works but it's a roundabout way of getting non-sensitive Env Vars to the deployment pod, such as GF_INSTALL_PLUGINS which isn't a sensitive Env Var, but requires a bit of setup to get working. This can be streamlined by implementing Env Var configuration,

(If applicable)If your feature request solves a bug please provide a link to the community issue

Describe the solution you'd like We should be able to configure non-sensitive env vars using the Env field for grafana deployments, this is already parsed by the operator but isn't configurable https://github.com/integr8ly/grafana-operator/blob/master/pkg/controller/model/grafanaDeployment.go#L455-L463

The feature should implement a new Spec.Deployment.Env field which will be parsed for content similar to

func getEnvFrom(cr *v1alpha1.Grafana) []v13.EnvFromSource {
	var envFrom []v13.EnvFromSource
	if cr.Spec.Deployment != nil && cr.Spec.Deployment.EnvFrom != nil {
		for _, v := range cr.Spec.Deployment.EnvFrom {
			envFrom = append(envFrom, *v.DeepCopy())
		}
	}
	return envFrom
}

The new function should return all currently default Envs as defined here along with appended Envs provided by the user. Which will then be used by the operator to be passed into the grafana deployment pod

Describe alternatives you've considered We could keep using EnvFrom, but this is a slightly shorter and cleaner way of achieving the same goal

Additional context NA

Existing solutions NA

[pb82]

What makes this a bit more complicated is the fact that users could provide admin credentials (GF_ADMIN_USER & GF_ADMIN_PASSWORD) through env. The operator needs to be aware of this and currently checks the envFrom source. We would now also have to check the vars from env and check for admin credentials (and prioritize if both sources provide credentials).

[jasaltvik]

I guess this can be closed? Ref: https://github.com/grafana-operator/grafana-operator/pull/500

I also created https://github.com/grafana-operator/grafana-operator/issues/890

[NissesSenap]

Thanks for pointing this out @jasaltvik