When creating a CloudWatch Metric for an Application Load Balancer it is
neccessary to use the suffix of the ARN as the reference to the load
balancer. This commit exposes that as an attribute on the `aws_alb`
resource to prevent the need to use regular expression substitution to
make the reference.
Fixes#8808.
In order to satisify scenarios where a lifecycle is block is used, we
would need the AWS ALB name field to be autogenerated. WE follow the
same work as AWS ELB, we prefix it with `tl-lb-`
```
% make testacc TEST=./builtin/providers/aws TESTARGS='-run=TestAccAWSALB_'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /terraform/vendor/)
2016/09/08 12:43:40 Generated command/internal_plugin_list.go
TF_ACC=1 go test ./builtin/providers/aws -v -run=TestAccAWSALB_ -timeout
120m
=== RUN TestAccAWSALB_basic
--- PASS: TestAccAWSALB_basic (79.81s)
=== RUN TestAccAWSALB_generatedName
--- PASS: TestAccAWSALB_generatedName (93.81s)
=== RUN TestAccAWSALB_namePrefix
--- PASS: TestAccAWSALB_namePrefix (73.48s)
=== RUN TestAccAWSALB_tags
--- PASS: TestAccAWSALB_tags (181.32s)
=== RUN TestAccAWSALB_noSecurityGroup
--- PASS: TestAccAWSALB_noSecurityGroup (66.03s)
=== RUN TestAccAWSALB_accesslogs
--- PASS: TestAccAWSALB_accesslogs (130.82s)
PASS
ok github.com/hashicorp/terraform/builtin/providers/aws 625.285s
```
This commit adds an `arn` field to `aws_alb` and `aws_alb_target_group`
resources, in order to present a more coherant user experience to people
using resource variables in fields suffixed "arn".
This commit adds a resource, acceptance tests and documentation for the
new Application Load Balancer (aws_alb). We choose to use the name alb
over the package name, elbv2, in order to avoid confusion.
This is the first in a series of commits to fully support the new
resources necessary for Application Load Balancers.
