How to allow/block SMTP traffic for a particular SolusIO VPS?

Question

How to allow/block SMTP traffic for a particular SolusIO VPS?

Answer

This functionality is yet to be implenemented in SolusIO. There is a feature request for such functionality with ID #SIO-4345 which is under consideration for implementation.

As a workaround:

1. Login to SolusIO admin panel
2. Browse to SolusIO > Virtual Servers and note the Hypervisor ID(UUID) and ID of the corresponding VPS:
   
3. Connect to the corresponding Compute Resource via SSH
4. Open the file /usr/local/solus/ovs/UUID/rules in text editor.
   Where UUID is the UUID of the corresponding VPS from step 2
5. Add the following rules to disable SMTP traffic or Remove them to enable SMTP traffic:

   CONFIG_TEXT: ovs-ofctl add-flow br-int "in_port=sol-ID priority=37000 tcp tcp_dst=25 action=drop"
   ovs-ofctl add-flow br-int "in_port=sol-ID priority=37000 tcp tcp_dst=465 action=drop"
   ovs-ofctl add-flow br-int "in_port=sol-ID priority=37000 tcp tcp_dst=587 action=drop"
   ovs-ofctl add-flow br-int "in_port=sol-ID priority=37000 tcp6 tcp_dst=25 action=drop"
   ovs-ofctl add-flow br-int "in_port=sol-ID priority=37000 tcp6 tcp_dst=465 action=drop"
   ovs-ofctl add-flow br-int "in_port=sol-ID priority=37000 tcp6 tcp_dst=587 action=drop"

   Replace ID with the ID of the VPS from step 2.

6. Restart VPS at SolusIO > Virtual Servers > VPS