class Aspera::CosNode

def generate_token

potentially call this if delegated token is expired 
def generate_token
  # OAuth API to get delegated token
  delegated_oauth=Oauth.new({
    :type       => :oauth2,
    :base_url   => @auth_url,
    :grant      => :delegated_refresh,
    :api_key    => @api_key,
    :token_field=> TOKEN_FIELD
  })
  # get delagated token to be placed in rest call header and in transfer tags
  @add_ts['tags']['aspera']['node']['storage_credentials']['token'][TOKEN_FIELD]=delegated_oauth.get_authorization().gsub(/^Bearer /,'')
  @params[:headers]={'X-Aspera-Storage-Credentials'=>JSON.generate(@add_ts['tags']['aspera']['node']['storage_credentials'])}
end

def initialize(bucket_name,storage_endpoint,instance_id,api_key,auth_url=IBM_CLOUD_TOKEN_URL) 

def initialize(bucket_name,storage_endpoint,instance_id,api_key,auth_url=IBM_CLOUD_TOKEN_URL)
  @auth_url=auth_url
  @api_key=api_key
  s3_api=Aspera::Rest.new({
    :base_url       => storage_endpoint,
    :not_auth_codes => ['401','403'], # error codes when not authorized
    :headers        => {'ibm-service-instance-id' => instance_id},
    :auth           => {
    :type      => :oauth2,
    :base_url  => @auth_url,
    :grant     => :ibm_apikey,
    :api_key   => @api_key
    }})
  # read FASP connection information for bucket
  xml_result_text=s3_api.call({:operation=>'GET',:subpath=>bucket_name,:headers=>{'Accept'=>'application/xml'},:url_params=>{'faspConnectionInfo'=>nil}})[:http].body
  ats_info=XmlSimple.xml_in(xml_result_text, {'ForceArray' => false})
  Aspera::Log.dump('ats_info',ats_info)
  super({
    :base_url => ats_info['ATSEndpoint'],
    :auth     => {
    :type     => :basic,
    :username => ats_info['AccessKey']['Id'],
    :password => ats_info['AccessKey']['Secret']}})
  # prepare transfer spec addition
  @add_ts={'tags'=>{'aspera'=>{'node'=>{'storage_credentials'=>{
    'type'  => 'token',
    'token' => {TOKEN_FIELD=>nil}
    }}}}}
  generate_token
end