How to merge 2 tuples?

Terraform
2

The magic you need for this is concat.

PS C:\Development\discuss\68098> terraform console
> concat(local.server_data_disks, local.server_sql_disks)
[
  {
    "caching" = "ReadWrite"
    "data_disk_size_gb" = 128
    "data_disk_storage_account_type" = "Standard_LRS"
    "name" = "datadisk1"
  },
  {
    "caching" = "ReadWrite"
    "data_disk_size_gb" = 128
    "data_disk_storage_account_type" = "Standard_LRS"
    "name" = "datadisk2"
  },
  {
    "caching" = "ReadWrite"
    "data_disk_size_gb" = "80"
    "data_disk_storage_account_type" = "Standard_LRS"
    "name" = "datadisk5"
  },
  {
    "caching" = "ReadWrite"
    "data_disk_size_gb" = "25"
    "data_disk_storage_account_type" = "Standard_LRS"
    "name" = "datadisk6"
  },
]
>

As you have found, merge takes an arbitrary number of maps or objects, and returns a single map or object that contains a merged set of elements from all arguments. Whereas, what you have here is two lists.

Hope that helps!

Happy Terraforming