Aws::AssumeRoleCredentials throwing exception about :region

[zepplen]

I am having an issue using the Aws::AssumeRoleCredentials call. It is throwing an exception requiring :region to be set. Setting :region does not fix the issues.

ruby 2.1.5p273 (2014-11-13 revision 48405) [x86_64-linux]
[1] pry(main)> require 'aws-sdk'
�[0G[2] pry(main)> Aws::VERSION
[3] pry(main)> assumed_credentials = Aws::AssumeRoleCredentials.new(
[3] pry(main)*       role_arn: 'arn:aws:iam::111111111111:role/role_name',
[3] pry(main)*       role_session_name: 'example_session'
[3] pry(main)*   )
[4] pry(main)> puts
[5] pry(main)> puts
[6] pry(main)> puts 'Trying to set :region'
[7] pry(main)> assumed_credentials = Aws::AssumeRoleCredentials.new(
[7] pry(main)*       region: 'us-east-1',
[7] pry(main)*       role_arn: 'arn:aws:iam::111111111111:role/role_name',
[7] pry(main)*       role_session_name: 'example_session'
[7] pry(main)*   )
[8] pry(main)> puts
[9] pry(main)> puts
[10] pry(main)> puts 'Work around'
[11] pry(main)> Aws.config[:region] = 'us-east-1'
[12] pry(main)> assumed_credentials = Aws::AssumeRoleCredentials.new(
[12] pry(main)*       role_arn: 'arn:aws:iam::111111111111:role/role_name',
[12] pry(main)*       role_session_name: 'example_session'
[12] pry(main)*   )
[13] pry(main)> Aws.config.delete(:region)
[14] pry(main)> puts
[15] pry(main)> puts
[16] pry(main)> puts 'Workaound w/ region set'
[17] pry(main)> Aws.config[:region] = 'us-east-1'
[18] pry(main)> assumed_credentials = Aws::AssumeRoleCredentials.new(
[18] pry(main)*       region: 'us-east-1',
[18] pry(main)*       role_arn: 'arn:aws:iam::111111111111:role/role_name',
[18] pry(main)*       role_session_name: 'example_session'
[18] pry(main)*   )
[19] pry(main)> Aws.config.delete(:region)
[20] pry(main)> exit
=> true
=> "2.1.29"
Aws::Errors::MissingRegionError: missing region; use :region option or export region name to ENV['AWS_REGION']
from /home/mtrimmer/.rvm/gems/ruby-2.1.5@wormhole/gems/aws-sdk-core-2.1.29/lib/aws-sdk-core/plugins/regional_endpoint.rb:32:in `after_initialize'

=> nil

=> nil
Trying to set :region
=> nil
Aws::Errors::MissingRegionError: missing region; use :region option or export region name to ENV['AWS_REGION']
from /home/mtrimmer/.rvm/gems/ruby-2.1.5@wormhole/gems/aws-sdk-core-2.1.29/lib/aws-sdk-core/plugins/regional_endpoint.rb:32:in `after_initialize'

=> nil

=> nil
Work around
=> nil
=> "us-east-1"
=> #<Aws::AssumeRoleCredentials:0x00000001526380
 @client=#<Aws::STS::Client>,
 @credentials=#<Aws::Credentials access_key_id="********************">,
 @expiration=2015-10-13 19:53:11 UTC,
 @mutex=#<Mutex:0x00000000f000f0>,
 @options=
  {:role_arn=>"arn:aws:iam::111111111111:role/role_name",
   :role_session_name=>"example_session"}>
=> "us-east-1"

=> nil

=> nil
Workaound w/ region set
=> nil
=> "us-east-1"
ArgumentError: unexpected value at params[:region]
from /home/mtrimmer/.rvm/gems/ruby-2.1.5@wormhole/gems/aws-sdk-core-2.1.29/lib/aws-sdk-core/param_validator.rb:26:in `validate!'
=> "us-east-1"

[trevorrowe]

The stack trace isn't very helpful unless you look pretty deep. When you construct an instance of Aws::AssumeRoleCredentials, an Aws::STS::Client is constructed when one is not given. This client requires a region. The client class will attempt to load the region from ENV['AWS_REGION'] but it seems like a pass-through like you attempted would be more helpful.

I've fixed the documentation so that the :client option will appear in the api docs. I'll see about making the region option (and others) pass through to the client constructor call.