network: disallow legacy hostNetwork together with non-default provider

Fixes: #13692

Since the introduction of the "host" network provider, the  legacy
"hostNetwork" setting is intended to be used only in combination with
the default network provider (""), but the code did not enforce this.

This change adds the required validation checks to throw errors
in invalid constellations.

Signed-off-by: Michael Adam <obnox@samba.org>

pkg/apis/ceph.rook.io/v1/network.go

@@ -39,6 +39,9 @@ func (n *NetworkSpec) IsHost() bool {
 }
 
 func ValidateNetworkSpec(clusterNamespace string, spec NetworkSpec) error {
+	if spec.HostNetwork && (spec.Provider != NetworkProviderDefault) {
+		return errors.Errorf("the legacy hostNetwork setting is only valid with the default network provider'\"\"' and not with '%q'", spec.Provider)
+	}
 	if spec.IsMultus() {
 		if len(spec.Selectors) == 0 {
 			return errors.Errorf("at least one network selector must be specified when using the %q network provider", NetworkProviderMultus)