r/aws_dynamodb_table: Ensure ttl is properly read

[bflad]

Closes #2442

Previously it was pointing to a non-existent timeToLive attribute and not returning any errors.

make testacc TEST=./aws TESTARGS='-run=TestAccAWSDynamoDbTable'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -run=TestAccAWSDynamoDbTable -timeout 120m
=== RUN   TestAccAWSDynamoDbTable_importBasic
--- PASS: TestAccAWSDynamoDbTable_importBasic (63.75s)
=== RUN   TestAccAWSDynamoDbTable_importTags
--- PASS: TestAccAWSDynamoDbTable_importTags (61.60s)
=== RUN   TestAccAWSDynamoDbTable_importTimeToLive
--- PASS: TestAccAWSDynamoDbTable_importTimeToLive (56.04s)
=== RUN   TestAccAWSDynamoDbTable_basic
--- PASS: TestAccAWSDynamoDbTable_basic (324.05s)
=== RUN   TestAccAWSDynamoDbTable_streamSpecification
--- PASS: TestAccAWSDynamoDbTable_streamSpecification (51.13s)
=== RUN   TestAccAWSDynamoDbTable_tags
--- PASS: TestAccAWSDynamoDbTable_tags (56.07s)
=== RUN   TestAccAWSDynamoDbTable_gsiUpdate
--- PASS: TestAccAWSDynamoDbTable_gsiUpdate (195.70s)
=== RUN   TestAccAWSDynamoDbTable_ttl
--- PASS: TestAccAWSDynamoDbTable_ttl (71.26s)
PASS
ok  	github.com/terraform-providers/terraform-provider-aws/aws	879.650s

[radeksimko]

Just 1 question + one suggestion.

[radeksimko]

Nitpick: As we know we're only ever going to need 1 element of the slice we can make it a fixed-size array:

timeToLiveList := [...]interface{}{
	map[string]interface{}{
		"attribute_name": *timeToLiveOutput.TimeToLiveDescription.AttributeName,
		"enabled":        (*timeToLiveOutput.TimeToLiveDescription.TimeToLiveStatus == dynamodb.TimeToLiveStatusEnabled),
	},
}

[radeksimko]

Any reason we're checking timeToLiveOutput.TimeToLiveDescription.AttributeName instead of timeToLiveOutput.TimeToLiveDescription here?

I guess we can assume AttributeName is not nil if the parent struct is not nil?

[bflad]

We cannot actually. 😄 It causes a panic on AttributeName dereference in the basic acceptance testing without the additional nil check. I will update it to check both the parent struct and AttributeName

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x2537d6f]

goroutine 375 [running]:
github.com/terraform-providers/terraform-provider-aws/aws.flattenAwsDynamoDbTableResource(0xc42019b650, 0x3217440, 0xc420532480, 0xc4207e8160, 0x0, 0x5168700)
	/Users/bflad/go/src/github.com/terraform-providers/terraform-provider-aws/aws/resource_aws_dynamodb_table.go:823 +0x1a1f

[bflad]

@radeksimko updated!

• Add timeToLiveOutput.TimeToLiveDescription nil check
• Simplify logic to d.Set ttl

make testacc TEST=./aws TESTARGS='-run=TestAccAWSDynamoDbTable'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -run=TestAccAWSDynamoDbTable -timeout 120m
=== RUN   TestAccAWSDynamoDbTable_importBasic
--- PASS: TestAccAWSDynamoDbTable_importBasic (58.48s)
=== RUN   TestAccAWSDynamoDbTable_importTags
--- PASS: TestAccAWSDynamoDbTable_importTags (73.62s)
=== RUN   TestAccAWSDynamoDbTable_importTimeToLive
--- PASS: TestAccAWSDynamoDbTable_importTimeToLive (63.36s)
=== RUN   TestAccAWSDynamoDbTable_basic
--- PASS: TestAccAWSDynamoDbTable_basic (387.61s)
=== RUN   TestAccAWSDynamoDbTable_streamSpecification
--- PASS: TestAccAWSDynamoDbTable_streamSpecification (81.41s)
=== RUN   TestAccAWSDynamoDbTable_tags
--- PASS: TestAccAWSDynamoDbTable_tags (59.59s)
=== RUN   TestAccAWSDynamoDbTable_gsiUpdate
--- PASS: TestAccAWSDynamoDbTable_gsiUpdate (188.32s)
=== RUN   TestAccAWSDynamoDbTable_ttl
--- PASS: TestAccAWSDynamoDbTable_ttl (53.18s)
PASS
ok  	github.com/terraform-providers/terraform-provider-aws/aws	965.599s

[radeksimko]

This is certainly more compact, but it's still a slice, not an array. The three dots I mentioned in my example were turning it into an array.

https://blog.golang.org/go-slices-usage-and-internals

It's certainly not a big deal though.

[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!