Murano: How to find network ids for automatically created networks

Murano deploys the specific network topology for a Murano environment by default. Murano creates a new private network then adds a new subnet and finally attaches this new network to the router.

If someone is writing an application, which wants to add some  Heat resources into the stack it might be a requirement to pass some network ids to the resource.

As networking is usually hidden from an user in the depth of Core library and it is not so obvious how to get these ids.

Here is a way I do this in my apps:

- $net: $.environment.defaultNetworks.environment
- If: $net != null
  Then:
     - $.environment.reporter.report($this, '[VMCluster]Using existing external network')
- $netRef: $net._getNetworkName() 

- $subnetRef: $net._getSubnetName()
- $extNetId: $net._getExternalNetId()

[Note: in Icehouse version there is no underscore in the name of these functions]

defaultNetwroks property of Environment contains a networking information for created networks.  Actual implementation of networking could be found here (https://github.com/stackforge/murano/blob/master/meta/io.murano/Classes/resources/NeutronNetwork.yaml) [Note that it should be moved soon to guthub.com/openstack/murano]


In the example above I got all necassary information for my networks:

• $netRef: will contain a Heat resource name for the network so that in embeded Heat template I can just use {get_resource: $netRef }
• $subnetRef: will contain a Heat resource name for subnet resource. Could be used as a reference in Embeded Heat template as {get_resource: $subnetRef }
• $extNetId: will contain an id of external network attached to a router. It is a network where application will allocate floating IPs. You might need this network id for LBaaS Pool resource.

On Juno version of OpenStack and Murano it will be necessary to explicitly cast network to NeutronNetwork like in the example below:

- $netRef: $net.cast('io.murano.resources.NeutronNetwork')._getNetworkName()
- $subnetRef: $net.cast('io.murano.resources.NeutronNetwork')._getSubnetName()
- $extNetId: $net.cast('io.murano.resources.NeutronNetwork')._getExternalNetId()

That is it about networks ids.
Enjoy!