Azure ARM Template variable: Get Subscription name property - azure

Question

Is there a way to get the current subscriptions name into a variable?
Something like this:
"variables": {
"Purpose": "[subscription().SubscriptionName]"
},
Visual Studio says "A property of 'subscription' must be one of the following: id, subscriptionId, tenantId." So the above won't work.
I've also found some examples of the "reference" function and tried to use it thus:
"variables": {
"SubName": "[reference('/subscriptions/subscription().subscriptionId','2015-01-01').outputs.name.value]"
},
But when calling the template it errors with:
function 'reference' is not expected at this location
I'm not sure where I should put it and how I get it into a variable.
In PowerShell, I could do this:
(Get-AzureRmSubscription).subscriptionname
For the sack of interest, we have several subscriptions. The subscription name contains a 3 digit "short code" that is used in the naming of resource groups within the given subscription. It serves no purpose other than make it easier to pinpoint what belongs to what. It is part of our naming convention to help admins (who aren't particularly familiar with Azure) easily see what resources are where. I know there are other ways like RBAC etc, but Microsoft's incessant credential cookie capture doesn't lend itself to logging in with different credentials to different subscriptions.
Thanks
W.

Answer 1

At the time of writing this answer (2016 Oct 16) I'm afraid you can't.
According to the docs, this is what subsbscription() returns:
{
"id": "/subscriptions/#####",
"subscriptionId": "#####",
"tenantId": "#####"
}
So you should expect failing on subscription().SubscriptionName.
In the same doc I linked, there is a discussion around this in the comments section, see comment #2694777590 where a Microsoftie say:
Ok - I've added a bug to add the name attribute to the subcription() expression.
this was 2016 June 6, So I guess it's on the way.
As a workaround, you could inject the subscription name from the thing that is executing the template. For example if it's PowerShell you could do
$subName = (Get-AzureRmSubscription).subscriptionname
New-AzureRmResourceGroupDeployment ... -SecscriptionName $subName
Also, I don't know what's the purpose of that string manipulation based on subscription name you talked about, but if is to create subscription scoped unique names, a good practice is to use uniqueString(subscription().subscriptionId) as part of the name.

Answer 2

The subscription() now does have an additional attribute displayName, according to documentation.
The following should work for you:
"variables": {
"Purpose": "[subscription().displayName]"
}

Answer 3

You should be able to use:
subscription().displayName
(I'll get a bug filed on the VS behavior)

Answer 4

I was able to get subscription().subscriptionId to work in a variable my template.
I think this error you are seeing is a result of how Azure reads the template. Based on Microsoft's reference documentation, references cannot be used in variables:
Remarks
The reference function derives its value from a runtime state, and therefore cannot be used in the variables section.
I got the same function 'reference' is not expected at this location until I moved my actual reference call into the body of the template.