environment agnostic ARM template parameter file

Question

I have a (simplified) ARM template for an Storage Account deployment:

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters":{
    "env_storage_name": {
      "type": "string"
    }
  },
  "resources":[
    {
        "type": "Microsoft.Storage/storageAccounts",
        "name":"[parameters('env_storage_name')]",
        "apiVersion": "2019-06-01"
    }
  ]
}

This template uses the associated parameter file:

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentParameters.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "env_storage_name": {
            "value": "<env>-storage_name"
        }
    }
}

My goal is to deploy this template using Powershell by:

az deployment group create --name "someDeploymentName" --resource-group "myRG" --template-file "pathToTemplate.json" --parameters "pathToParameters.json"

I have googled quite a bit, but so far I havent found a way to dynamically replace the env substring in my parameter with e.g. "dev", "tst", "acc", "prd".What I want to do is effectively use the same Powershell command an "pipe in" the environment. I have tried to play around with variables, but so far I haven't managed to get it done.

Is that possible? Can anyone help me out?

Answer 1

The solution that solves my problem is, to use variables to concatinate my relevant resource names etc from parameters. It took me a while understand the possibilities that ARM gives you here.

I am now using this template:

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "subscription": {
        "type": "string"
      },
        "env": {
        "type": "string"
      }
    },
    "variables": {
        "storage_name":  "[concat(parameters('subscription'),'-',parameters('env'),'-storage_account_name')]"
    },
    "resources": [
        {
          "type": "Microsoft.Storage/storageAccounts",
          "name":"[variables('storage_name')]",
          "apiVersion": "2019-06-01"
      }
    ]
}

and feed it with this parameter file:

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentParameters.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
            "subscription": {
            "value": "mySub"
        },
            "env": {
            "value": "dev"
        }
    }
}

So the only thing that I have to do is change the "env" parameter in the parameter file.

This does NOT give me the possibility to push a button and all four environments are created sequentially, but that is not part of the requirements atm. I still have to manually change "dev" to "tst" for example and rerun my PowerShell script, but that is acceptable for me.