Introduction

Use case

Administrator wants to be able to assign Vlan to the Isolated network with the Source Nat Service enabled. He also would like those networks to never be GCed.

Architecture and Design description

1) Network offering creation

Have to remove the restriction when specifyVlan=true is allowed for Shared Network Offerings only. Should allow it for Isolated Network Offerings as well.  When the parameter is set to true, it means that the Admin has to specify the Vlan when he creates the network.

2) Network creation

Only ROOT admin is aware of the Vlans in the system. So only he can create the tier with the vlan defined, on behalf of the regular user. UI should handle it and don't display network offerings with "specifyVlan=true" when create a new tier from the VPC view.

3) Network GC

To ensure that the network is never picked up by GC, set isPersistent flag to true when create network offering. Network GC thread will exclude those networks when it does the cleanup.

DB changes

No DB changes

UI changes

• When create tier inside the VPC, show offerings with specifyVlan=true only on Root admin UI
• When offering with specifyVlan=true is selected from the drop down list, display the Vlan field on create network dialog.

Question: should vlan come from the range defined on the Physical network? If so, we might need a set of APIs to display free vs allocated vlans. Or should it be the Vlan outside of the range defined on the physical network (just the way we do for Shared networks)?