droplet: Prevent inconsistent plan when enabling IPv6. (#982)

digitalocean/droplet/resource_droplet.go

@@ -14,6 +14,7 @@ import (
  "github.com/digitalocean/terraform-provider-digitalocean/digitalocean/tag"
  "github.com/digitalocean/terraform-provider-digitalocean/digitalocean/util"
  "github.com/hashicorp/terraform-plugin-sdk/v2/diag"
+ "github.com/hashicorp/terraform-plugin-sdk/v2/helper/customdiff"
  "github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
  "github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
  "github.com/hashicorp/terraform-plugin-sdk/v2/helper/validation"
@@ -148,6 +149,7 @@ func ResourceDigitalOceanDroplet() *schema.Resource {
 
  "ipv6_address": {
  Type: schema.TypeString,
+ Optional: true,
  Computed: true,
  },
 
@@ -220,6 +222,22 @@ func ResourceDigitalOceanDroplet() *schema.Resource {
  ValidateFunc: validation.NoZeroValues,
  },
  },
+
+ CustomizeDiff: customdiff.All(
+ // If the `ipv6` attribute is changed to `true`, we need to mark the
+ // `ipv6_address` attribute as changing in the plan. If not, the plan
+ // will become inconsistent once the address is known when referenced
+ // in another resource such as a domain record, e.g.:
+ // https://github.com/digitalocean/terraform-provider-digitalocean/issues/981
+ customdiff.IfValueChange("ipv6",
+ func(ctx context.Context, old, new, meta interface{}) bool {
+ return !old.(bool) && new.(bool)
+ },
+ customdiff.ComputedIf("ipv6_address", func(ctx context.Context, d *schema.ResourceDiff, meta interface{}) bool {
+ return d.Get("ipv6").(bool)
+ }),
+ ),
+ ),
  }
 }