[occi-wg] Networks: attributes and verbs

[Richard Davies]

All,

For me, the largest gap in the nouns, verbs and attributes is with regards
to networks. Here are some thoughts on capabilities which I believe we need
and options to implement these - feedback please!

Basics
------
Networks will be a top level noun, along with servers and storage. Users
will link a server to a network to specify that the server is attached to
that network. There will be one special network presenting the public
internet, and users can create additional private networks for themselves.


The open questions are:


Public static IPs
-----------------
On all public clouds, customers can purchase static IPs (e.g. Amazon Elastic
IP) for uses where a constant server location is helpful (e.g. typical web
hosting).

We'll need a means for customers to create, list and destroy the public
static IPs which they own.

Two options:
a) Public static IPs are first-class nouns
b) They are listed inside the public internet network

I'd favour a), which is the case with most public clouds today.


Active networks
---------------
At its most basic, a network should behave like a plain ethernet switch - it
provides no services at all, and simply connects all the servers which
attach to it. Servers are free to chose their own IP addresses, etc.

There are a number of active services which are possible on a network:
- Central DHCP server
- Bridge to a physical VLAN (e.g. containing physical dedicated servers in
  colocation with the cloud provider)
- Load balancer between several web servers on a private network across to a
  single IP on the public internet.
- etc.

Two options:

a) The network object itself can optionally provide these. They are
   configured using attributes and verbs on the network.
b) There are separate 'appliance' objects which provide these services, and
   are linked onto the network just as a server would be (e.g. a 'DHCP
   server' appliance and or 'load balancer' appliance).

a) feels lighter-weight, but I suspect b) is more powerful. As such the
choice depends on how far OCCI wants to go down this route.


Linking to a network
--------------------
Finally, there are a few attributes which can specified on the link when a
server is linked to a network:
- The physical interface on the server (nic:0, nic:1, etc.)
- Port firewalling rules (e.g. connect server to the internet network, but only
  allow port 80 inbound)
- IP firewalling rules (e.g. connect server to the private network, and
  allow it to communicate on 192.168.0.0-23 but no others)
- Local DHCP (e.g. the server operating system is internally configured
  to DHCP. I am connecting it to the public internet, and want it to appear
  with my assigned public static IP. Please send a DHCP response with that
  specific IP address).

I think that all of these are best implemented as attributes on the link.