Get Network In / Network Out Data for a Virtual Network (VNet) using Azure REST API

Question

I'm trying to aggregate the Microsoft.Insights Network In & Network Out data for VMs grouped by Virtual Network and am having trouble figuring out how to do that given that VMs only return their subscription & resource group when queried via the API.

I'm wondering if there's a way to have a single API call return either:

a) VMs by VNET

OR

b) VMs w/ their VNET info

And if not, what's the best method of getting a list of VMs per VNet?

From all the data I've been reading, it seems like the only way to get this association is via /networkinterfaces. Is that correct?

VNET is within: properties/ipConfigurations/properties/subnet/ip

VM is within: properties/virtualMachine/id

I found an old question on MS from 2014 suggesting this wasn't available back then:

https://social.msdn.microsoft.com/Forums/en-US/95b7f1bd-c557-4866-ae4e-57b58d802a31/how-do-i-use-powershell-to-get-virtual-machine-settings-dns-vnet-etc?forum=WAVirtualMachinesforWindows

Really hoping they've improved things in the last 2+ years. It's a bit frustrating to have a VNet be a requirement of a VM on POST, but not be part of the GET response.

NWilliams NWilliams · Accepted Answer · 2017-03-23T16:21:19

OK, so this went stale, so I'll give an answer in case anyone else lands here looking.

First off - no, there is no way to get this association directly.

As indicated in the question, NICs appear to be the solution.

I requested all of the NIC data back (across all subscriptions to ensure full coverage of all VNETS). (https://docs.microsoft.com/en-us/rest/api/network/list-network-interface-cards-within-a-resource-group)'

Within this data, you can determine the parent vnet by reading the subnet data...

Here's a little test I put together in Python that seems to accomplish the task:

Data response from Azure (shows 2 NICS): { "value": [ { "name": "REDACTED", "id": "REDACTED", "etag": "REDACTED", "location": "eastus", "type": "Microsoft.Network/networkInterfaces", "properties": { "provisioningState": "Succeeded", "macAddress": "REDACTED", "primary": true, "virtualMachine": { "id": "/subscriptions/REDACTED/resourceGroups/REDACTED/providers/Microsoft.Compute/virtualMachines/MyVM1" }, "dnsSettings": { "internalDomainNameSuffix": "REDACTED", "dnsServers": [], "appliedDnsServers": [] }, "enableIPForwarding": false, "resourceGuid": "REDACTED", "networkSecurityGroup": { "id": "/subscriptions/REDACTED/resourceGroups/REDACTED/providers/Microsoft.Network/networkSecurityGroups/REDACTED" }, "ipConfigurations": [ { "etag": "W/\"REDACTED\"", "id": "/subscriptions/REDACTED/resourceGroups/REDACTED/providers/Microsoft.Network/networkInterfaces/REDACTED/ipConfigurations/ipconfig1", "name": "ipconfig1", "properties": { "subnet": { "id": "/subscriptions/REDACTED/resourceGroups/REDACTED/providers/Microsoft.Network/virtualNetworks/MyVNET1/subnets/REDACTED" }, "primary": true, "privateIPAddressVersion": "IPv4", "publicIPAddress": { "id": "/subscriptions/REDACTED/resourceGroups/REDACTED/providers/Microsoft.Network/publicIPAddresses/REDACTED" }, "privateIPAllocationMethod": "Dynamic", "privateIPAddress": "10.0.0.4", "provisioningState": "Succeeded" } } ], "enableAcceleratedNetworking": false } }, { "name": "REDACTED", "id": "REDACTED", "etag": "REDACTED", "location": "eastus", "type": "Microsoft.Network/networkInterfaces", "properties": { "provisioningState": "Succeeded", "macAddress": "REDACTED", "primary": true, "virtualMachine": { "id": "/subscriptions/REDACTED/resourceGroups/REDACTED/providers/Microsoft.Compute/virtualMachines/MyVM2" }, "dnsSettings": { "internalDomainNameSuffix": "REDACTED", "dnsServers": [], "appliedDnsServers": [] }, "enableIPForwarding": false, "resourceGuid": "REDACTED", "networkSecurityGroup": { "id": "/subscriptions/REDACTED/resourceGroups/REDACTED/providers/Microsoft.Network/networkSecurityGroups/REDACTED" }, "ipConfigurations": [ { "etag": "W/\"REDACTED\"", "id": "/subscriptions/REDACTED/resourceGroups/REDACTED/providers/Microsoft.Network/networkInterfaces/REDACTED/ipConfigurations/ipconfig1", "name": "ipconfig1", "properties": { "subnet": { "id": "/subscriptions/REDACTED/resourceGroups/REDACTED/providers/Microsoft.Network/virtualNetworks/MyVNET1/subnets/REDACTED" }, "primary": true, "privateIPAddressVersion": "IPv4", "publicIPAddress": { "id": "/subscriptions/REDACTED/resourceGroups/REDACTED/providers/Microsoft.Network/publicIPAddresses/REDACTED" }, "privateIPAllocationMethod": "Dynamic", "privateIPAddress": "10.0.0.4", "provisioningState": "Succeeded" } } ], "enableAcceleratedNetworking": false } } } ] }

Processing the data (note there are indentation issues in the output below):

def build_vms_by_net(data):
data = [data]
returnData = []
for i,obj in enumerate(data):
    if 'value' in obj:
        inner = obj['value']
        for j, obj2 in enumerate(inner):
            config = obj2['properties']['ipConfigurations']
            for k, obj3 in enumerate(config):
                if '/virtualNetworks/' in obj3['properties']['subnet']['id']:
                    vnetvals = obj3['properties']['subnet']['id'].split('/')
                    vnet = vnetvals[vnetvals.index('virtualNetworks')+1]
                else:
                    vnet = ''
            try:
                vmvals = obj2['properties']['virtualMachine']['id'].split('/')
                vm = vmvals[-1]
                subscriptionId = vmvals[vmvals.index('subscriptions')+1]
                resourceGroupName = vmvals[vmvals.index('resourceGroups')+1]
                if (vnet != '' and vm != ''):
                    returnData.append({
                        "nicId" : obj2['name'],
                        "vm"  : vm,
                        "vnet"    : vnet,
                        "subscriptionId" : subscriptionId,
                        "resourceGroupName" : resourceGroupName
                    })
            except Exception:
                # Azure has a habit of orphaning resources, in the event that
                # a nic is not associated with a virtual machine, we just don't
                # append its info and continue w/ the rest of the processing
                pass
                # as it likely means the VM was deleted, but not the NIC
            vnet = ''
            vm = ''
return returnData

The outpur is as follows: [ { "subscriptionId": "REDACTED", "vnet": "REDACTED", "nicId": "REDACTED", "vm": "REDACTED", "resourceGroupName": "REDACTED" }, { "subscriptionId": "REDACTED", "vnet": "REDACTED", "nicId": "REDACTED", "vm": "REDACTED", "resourceGroupName": "REDACTED" } ]

Looping over all of your resource groups, you'll build a complete list, which you can then process further to make a list of VMs by VNET if you so chose.

Note that you may need to beef up the error handling, but this test is plenty to get started...it can also be the basis of making connections between a lot of other resources within Azure that have "Resource Group" as their parent (another, simpler example is get a Gateway's parent VNet from it's data response).

Get Network In / Network Out Data for a Virtual Network (VNet) using Azure REST API

1 Answers