How to loop over multiple arrays for a resource

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.

user_4167200 · Answer

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.

How to loop over multiple arrays for a resource

1 Answers