Fix changing engine_version attempts to update resource class

[beny23]

Currently when changing a DMS instance, any change to the engine_version attempts to update the ReplicationInstanceClass

Fixes #0000

Changes proposed in this pull request:

• Bugfix to ensure DMS engine_version can be updated.

Output from acceptance testing:

$ make testacc TESTARGS='-run=TestAccAWSAvailabilityZones'

...

[bflad]

Hi @beny23 👋 Thanks for submitting this!

I was able to write up an acceptance test to cover this behavior and prevent regressions in the future:

func TestAccAWSDmsReplicationInstance_EngineVersion(t *testing.T) {
	resourceName := "aws_dms_replication_instance.test"
	rName := acctest.RandomWithPrefix("tf-acc-test")

	resource.Test(t, resource.TestCase{
		PreCheck:     func() { testAccPreCheck(t) },
		Providers:    testAccProviders,
		CheckDestroy: dmsReplicationInstanceDestroy,
		Steps: []resource.TestStep{
			{
				Config: testAccAWSDmsReplicationInstanceConfig_EngineVersion(rName, "2.4.2"),
				Check: resource.ComposeTestCheckFunc(
					checkDmsReplicationInstanceExists(resourceName),
					resource.TestCheckResourceAttr(resourceName, "engine_version", "2.4.2"),
				),
			},
			{
				ResourceName:            resourceName,
				ImportState:             true,
				ImportStateVerify:       true,
				ImportStateVerifyIgnore: []string{"apply_immediately"},
			},
			{
				Config: testAccAWSDmsReplicationInstanceConfig_EngineVersion(rName, "2.4.3"),
				Check: resource.ComposeTestCheckFunc(
					checkDmsReplicationInstanceExists(resourceName),
					resource.TestCheckResourceAttr(resourceName, "engine_version", "2.4.3"),
				),
			},
		},
	})
}

func testAccAWSDmsReplicationInstanceConfig_EngineVersion(rName, engineVersion string) string {
	return fmt.Sprintf(`
resource "aws_dms_replication_instance" "test" {
  apply_immediately          = true
  engine_version             = %q
  replication_instance_class = "dms.t2.micro"
  replication_instance_id    = %q
}
`, engineVersion, rName)
}

Running it before your code update:

$ make testacc TEST=./aws TESTARGS='-run=TestAccAWSDmsReplicationInstance_EngineVersion'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -run=TestAccAWSDmsReplicationInstance_EngineVersion -timeout 120m
=== RUN   TestAccAWSDmsReplicationInstance_EngineVersion
--- FAIL: TestAccAWSDmsReplicationInstance_EngineVersion (440.26s)
    testing.go:527: Step 2 error: Error applying: 1 error occurred:
        	* aws_dms_replication_instance.test: 1 error occurred:
        	* aws_dms_replication_instance.test: InvalidParameterValueException: Invalid ReplicationInstance class:2.4.3
        	status code: 400, request id: 65419ced-bcf8-11e8-88cf-f15605cc1807




FAIL
FAIL	github.com/terraform-providers/terraform-provider-aws/aws	441.017s

After your code update, it actually uncovered a new issue:

$ make testacc TEST=./aws TESTARGS='-run=TestAccAWSDmsReplicationInstance_EngineVersion'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -run=TestAccAWSDmsReplicationInstance_EngineVersion -timeout 120m
=== RUN   TestAccAWSDmsReplicationInstance_EngineVersion
--- FAIL: TestAccAWSDmsReplicationInstance_EngineVersion (524.21s)
    testing.go:527: Step 2 error: Error applying: 1 error occurred:
        	* aws_dms_replication_instance.test: 1 error occurred:
        	* aws_dms_replication_instance.test: unexpected state 'upgrading', wanted target 'available'. last error: %!s(<nil>)




FAIL
FAIL	github.com/terraform-providers/terraform-provider-aws/aws	524.973s

I added upgrading as an allowed pending state for ModifyReplicationInstance, which got everything passing:

$ make testacc TEST=./aws TESTARGS='-run=TestAccAWSDmsReplicationInstance_EngineVersion'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -run=TestAccAWSDmsReplicationInstance_EngineVersion -timeout 120m
=== RUN   TestAccAWSDmsReplicationInstance_EngineVersion
--- PASS: TestAccAWSDmsReplicationInstance_EngineVersion (603.15s)
PASS
ok  	github.com/terraform-providers/terraform-provider-aws/aws	603.961s

[beny23]

@bflad thank you!!!

[bflad]

This has been released in version 1.38.0 of the AWS provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

[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!