Feature/multiple roles in config

[dsteinmo]

Changes proposed in this pull request:

• Allow multiple assume_role() blocks in provider configuration. This change allows these roles to be assumed one after the other until the last role in the list is reached (order matters).

Motivating use case: We have a user account that has access to assume a role within our organization's root account with permissions delegated to create org accounts and to assume the newly created admin role in new accounts, OrganizationAccountAccessRole. However, without first making this change to terraform-provider-aws, we were unable to double-hop from the user account's keys, to the account-creation role (this part works already), to the OrganizationAccountAccessRole in the new account (this change enables this, plus any number of additional layers).

Output from acceptance testing:

$ make testacc TESTARGS='-run=TestAccAWSAvailabilityZones'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./... -v -run=TestAccAWSAvailabilityZones -timeout 120m
?       github.com/terraform-providers/terraform-provider-aws   [no test files]
=== RUN   TestAccAWSAvailabilityZones_basic
--- PASS: TestAccAWSAvailabilityZones_basic (12.93s)
=== RUN   TestAccAWSAvailabilityZones_stateFilter
--- PASS: TestAccAWSAvailabilityZones_stateFilter (12.47s)
PASS
ok      github.com/terraform-providers/terraform-provider-aws/aws       25.440s

[aeschright]

Hi @dsteinmo! We released an update to how the config files are handled that now allows the roles to be correctly chained (using source_profile). Does that resolve your use case? You can see the details of what was addressed here: hashicorp/aws-sdk-go-base#4

[dsteinmo]

Looks good @aeschright! We can close off this PR for the record.

[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!