Feature/support address prefix as array

[eissko]

Description

There is usually situation when you need to override the default route of VNET or vnet peering by your custom rule which defines custom next hop (e.g. azure firewall). VNET can define multiple address spaces not only one. It is handy to define them as array. Of course it could be defined separately as new entry with new name and its address space - if you don't find it use-full, feel free to abandon the PR. The name of such route entry is then created by concatenation of the "route entry name" + "address space".

Enhancement

• Adding support for address prefix defined as array.
• Keeping backward compatibility of address prefix being type of string as well.
• Extending capability of input tfvars which can define address prefix as array ["10.10.1.0/24","10.10.2.0/24"].

Example of tfvars

route_table = {
    name = "test_route"
    route_entries = {
      re1 = {
        name          = "myroute1"
        prefix        = "255.0.0.0/8"
        next_hop_type = "None"
      },
      re2 = {
        name                   = "myroute2"
        prefix                 = ["255.255.0.0/16","8.8.8.8/32"]
        next_hop_type          = "VirtualAppliance"
        next_hop_in_ip_address = "192.168.10.6"
      },
      re3 = {
        name                   = "defaultroute"
        prefix                 = "0.0.0.0/0"
        next_hop_type          = "VirtualAppliance"
        next_hop_in_ip_address = "192.168.10.5"
      },
    }
}

Tested:

# azurerm_resource_group.rg1 will be created
  + resource "azurerm_resource_group" "rg1" {
      + id       = (known after apply)
      + location = "westeurope"
      + name     = "test-route-table"
    }

 # module.route_table_test.azurerm_route_table.route_table will be created
  + resource "azurerm_route_table" "route_table" {
      + disable_bgp_route_propagation = false
      + id                            = (known after apply)
      + location                      = "westeurope"
      + name                          = "test_route"
      + resource_group_name           = "test-route-table"
      + route                         = [
          + {
              + address_prefix         = "255.0.0.0/8"
              + name                   = "myroute1-255.0.0.0_8"
              + next_hop_in_ip_address = null
              + next_hop_type          = "None"
            },
          + {
              + address_prefix         = "255.255.0.0/16"
              + name                   = "myroute2-255.255.0.0_16"
              + next_hop_in_ip_address = "192.168.10.6"
              + next_hop_type          = "VirtualAppliance"
            },
          + {
              + address_prefix         = "8.8.8.8/32"
              + name                   = "myroute2-8.8.8.8_32"
              + next_hop_in_ip_address = "192.168.10.6"
              + next_hop_type          = "VirtualAppliance"
            },
          + {
              + address_prefix         = "0.0.0.0/0"
              + name                   = "defaultroute-0.0.0.0_0"
              + next_hop_in_ip_address = "192.168.10.5"
              + next_hop_type          = "VirtualAppliance"
            },
        ]
      + subnets                       = (known after apply)
      + tags                          = {
          + "deployment" = "by terraform"
          + "module"     = "route_table"
        }
    }

Plan: 2 to add, 0 to change, 0 to destroy.

[arnaudlh]

LGTM