Add ability to assume a role

[bacoboy]

While unicreds support specifying an alternate profile, it does not have the ability to assume a role using that (or the default) profile as shown in the AWS docs here.

Ideally, there'd be another optional parameter to specify the role to assume.

Even better would be the ability to use pre-defined profiles specified in ~/.aws/config as in this example:

[profile prod-admin]
role_arn = arn:aws:iam::XXXXXX:role/Admin
source_profile = default
region = us-east-1

which works with the aws cli as in this example (documented here):

$ aws --profile prod-admin ec2 describe-vpcs
[output snip]

Not really sure why ~/.aws/config seems to be ignored with the SDK but not in the CLI.

I've seen an additional role_arn parameter in the config as in this terraform example which only just came out in 0.8.7 so you can look how they did it here:

provider "aws" {
  region = "${var.aws_region}"
  profile = "default"
  assume_role {
    role_arn = "arn:aws:iam::${var.aws_account_number}:role/Admin"
  }
}

Looking over the credstash usage, this would be functionally equivalent to the --arn parameter

[bacoboy]

Looks like this is supported now so closing issue.