SetNewCompute ipv6 attrs in vpc when added

[jbardin]

If assign_generated_ipv6_block changes in a vpc, the diff has to reflect
that the ipv6 attrs are going to change.

As is often the case, diffs didn't match during apply (soon to be Provider produced inconsistent final plan) errors are caused by an upstream dependency. Here, a resource referencing the generated ipv6_cidr_block will get the incorrect value if it changes during apply.

Fixes #6710

$ TF_ACC=1 go test -v -run TestAccAWSVpc_AssignGeneratedIpv6CidrBlockFromFalse
=== RUN   TestAccAWSVpc_AssignGeneratedIpv6CidrBlockFromFalse
=== PAUSE TestAccAWSVpc_AssignGeneratedIpv6CidrBlockFromFalse
=== CONT  TestAccAWSVpc_AssignGeneratedIpv6CidrBlockFromFalse
--- PASS: TestAccAWSVpc_AssignGeneratedIpv6CidrBlockFromFalse (50.95s)
PASS

[bflad]

Hmm this appears related to #6721, but I had tagged it to wait until after the 0.12 SDK was merged in. Let me try to remember why.

[jbardin]

Oh, I missed that one, I only saw the upstream PR. I was in the area testing a recent SDK change, and thought I commit this update, but take whichever you prefer 👍

[bflad]

Ah yes, because the Terraform Provider SDK change was never backported to v0.11, so we don't want to merge failing testing:

--- FAIL: TestAccAWSVpc_AssignGeneratedIpv6CidrBlockFromFalse (33.74s)
    testing.go:538: Step 1 error: Error applying: 1 error occurred:
        	* aws_network_acl_rule.egress_internal_ipv6: aws_network_acl_rule.egress_internal_ipv6: diffs didn't match during apply. This is a bug with Terraform and should be reported as a GitHub Issue.

        Please include the following information in your report:

            Terraform Version: 0.11.14
            Resource ID: aws_network_acl_rule.egress_internal_ipv6
            Mismatch reason: extra attributes: ipv6_cidr_block
            Diff One (usually from plan): *terraform.InstanceDiff{mu:sync.Mutex{state:0, sema:0x0}, Attributes:map[string]*terraform.ResourceAttrDiff{"egress":*terraform.ResourceAttrDiff{Old:"", New:"true", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "from_port":*terraform.ResourceAttrDiff{Old:"", New:"0", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "network_acl_id":*terraform.ResourceAttrDiff{Old:"", New:"acl-00b2b660f3e1ac6a2", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "protocol":*terraform.ResourceAttrDiff{Old:"", New:"-1", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "rule_action":*terraform.ResourceAttrDiff{Old:"", New:"allow", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "rule_number":*terraform.ResourceAttrDiff{Old:"", New:"2", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "to_port":*terraform.ResourceAttrDiff{Old:"", New:"0", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}}, Destroy:false, DestroyDeposed:false, DestroyTainted:false, Meta:map[string]interface {}(nil)}
            Diff Two (usually from apply): *terraform.InstanceDiff{mu:sync.Mutex{state:0, sema:0x0}, Attributes:map[string]*terraform.ResourceAttrDiff{"egress":*terraform.ResourceAttrDiff{Old:"", New:"true", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "from_port":*terraform.ResourceAttrDiff{Old:"", New:"0", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "ipv6_cidr_block":*terraform.ResourceAttrDiff{Old:"", New:"2600:1f14:9d7:4900::/56", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "network_acl_id":*terraform.ResourceAttrDiff{Old:"", New:"acl-00b2b660f3e1ac6a2", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "protocol":*terraform.ResourceAttrDiff{Old:"", New:"-1", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "rule_action":*terraform.ResourceAttrDiff{Old:"", New:"allow", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "rule_number":*terraform.ResourceAttrDiff{Old:"", New:"2", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "to_port":*terraform.ResourceAttrDiff{Old:"", New:"0", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}}, Destroy:false, DestroyDeposed:false, DestroyTainted:false, Meta:map[string]interface {}(nil)}

        Also include as much context as you can about your config, state, and the steps you performed to trigger this error.

[jbardin]

Looks like this is nearly identical. I'll leave the existing PR for merging later.

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. Thanks!