How to loop over multiple arrays for a resource - arrays

Question

I want to create a resource for many regions, environments, apps, etc at once.
I'd like to do something like this:
param apps array = [
'app1'
'app2'
'app3'
]
param environments array = [
'alpha'
'beta'
]
param regions array = [
'ne'
'we'
'uks'
]
resource origin_group 'Microsoft.Cdn/profiles/origingroups#2021-06-01' = [ for region in regions: {
[ for env in environments: {
[ for app in apps: {
parent: profiles_global_fd_name_resource
name: '${env}-${region}-${app}-origin-group'
properties: {
loadBalancingSettings: {
sampleSize: 4
successfulSamplesRequired: 3
additionalLatencyInMilliseconds: 50
}
healthProbeSettings: {
probePath: '/'
probeRequestType: 'HEAD'
probeProtocol: 'Http'
probeIntervalInSeconds: 100
}
sessionAffinityState: 'Disabled'
}
}]
}]
}]
All docs mentioning nested loops talk about looping inside a resource to create many sub-resources. Not what I'm after. Perhaps another way would be to somehow merge all these arrays into a single array of objects of every possible iteration. Not sure where to start with that either.
Any help much appreciated.

Answer 1

This is not supported for the moment but it will (see Is there plans to support nested loop on resources?).
Using a little bit of math, you could achieve what you'd like (Not sure if you should):
param environments array = [ 'alpha', 'beta' ]
param regions array = [ 'ne', 'we', 'uks' ]
param apps array = [ 'app1', 'app2', 'app3' ]
// Setting some variables for clarity
var envCount = length(environments)
var regionCount = length(regions)
var appCount = length(apps)
// Setting the total number of combination
var originGroupCount = envCount * regionCount * appCount
// Iterate all possible combinations
output originGroupNames array = [for i in range(0, originGroupCount): {
name: '${environments[i / (regionCount * appCount) % envCount]}-${regions[i / appCount % regionCount]}-${apps[i % appCount]}-origin-group'
}]
this will output all possible combinations (I think) for origin group name.