Generate local appsettings.json nest structure from keyvault

getAppSettingsFromKeyVault.ps1

# input
# a--b--c--d, val
# a--b--c--e, val2
# f, val3
# output
# { a: { b: { c: { d: val; e: val2 } } }, f: val3 }

# this will ask for your azure credentials
Connect-AzureRmAccount

# this will ask for your keyvault name
$keyvault = (Get-AzureKeyVaultSecret).foreach{ Get-AzureKeyVaultSecret -VaultName $_.VaultName -Name $_.Name}

$dictionary = @{}
foreach ($kv in $keyvault) {
    $keys = $kv.Name -split "--"
    $prevDict = $dictionary
    For ($i=0; $i -le $keys.Count - 2; $i++) {
        $k = $keys[$i]
        If (-Not $prevDict.ContainsKey($k)) {
            $prevDict[$k] = @{}
        }
        $prevDict = $prevDict[$k]
    }
    $prevDict[$keys[-1]] = $kv.SecretValueText
}
$dictionary | ConvertTo-Json -depth 99

simply paste the powershell into your terminal and run or download+invoke the script directly.
It works on powershell 5.1+.
Powershell 6+ will indent the json in the way you'd expect, but you can "lint" or "prettify" it to get the same results

Connect-AzureRmAccount only needs to be run once. I recommend excluding it in future runs within the same terminal