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|
# frozen_string_literal: true
require 'securerandom'
module Fog
module AWS
module CredentialFetcher
INSTANCE_METADATA_HOST = "http://169.254.169.254"
INSTANCE_METADATA_TOKEN = "/latest/api/token"
INSTANCE_METADATA_PATH = "/latest/meta-data/iam/security-credentials/"
INSTANCE_METADATA_AZ = "/latest/meta-data/placement/availability-zone/"
CONTAINER_CREDENTIALS_HOST = "http://169.254.170.2"
module ServiceMethods
def fetch_credentials(options)
if options[:use_iam_profile] && Fog.mocking?
return Fog::AWS::Compute::Mock.data[:iam_role_based_creds]
end
if options[:use_iam_profile]
begin
role_data = nil
region = options[:region] || ENV["AWS_DEFAULT_REGION"]
if ENV["AWS_CONTAINER_CREDENTIALS_RELATIVE_URI"]
connection = options[:connection] || Excon.new(CONTAINER_CREDENTIALS_HOST)
credential_path = options[:credential_path] || ENV["AWS_CONTAINER_CREDENTIALS_RELATIVE_URI"]
role_data = connection.get(:path => credential_path, :idempotent => true, :expects => 200).body
session = Fog::JSON.decode(role_data)
if region.nil?
connection = options[:metadata_connection] || Excon.new(INSTANCE_METADATA_HOST)
token_header = fetch_credentials_token_header(connection, options[:disable_imds_v2])
region = connection.get(:path => INSTANCE_METADATA_AZ, :idempotent => true, :expects => 200, :headers => token_header).body[0..-2]
end
elsif ENV["AWS_WEB_IDENTITY_TOKEN_FILE"]
params = {
:Action => "AssumeRoleWithWebIdentity",
:RoleArn => options[:role_arn] || ENV.fetch("AWS_ROLE_ARN"),
:RoleSessionName => options[:role_session_name] || ENV["AWS_ROLE_SESSION_NAME"] || "fog-aws-#{SecureRandom.hex}",
:WebIdentityToken => File.read(options[:aws_web_identity_token_file] || ENV.fetch("AWS_WEB_IDENTITY_TOKEN_FILE")),
:Version => "2011-06-15",
}
sts_endpoint =
if ENV["AWS_STS_REGIONAL_ENDPOINTS"] == "regional" && region
"https://sts.#{region}.amazonaws.com"
else
"https://sts.amazonaws.com"
end
connection = options[:connection] || Excon.new(sts_endpoint, :query => params)
document = Nokogiri::XML(connection.get(:idempotent => true, :expects => 200).body)
session = {
"AccessKeyId" => document.css("AccessKeyId").children.text,
"SecretAccessKey" => document.css("SecretAccessKey").children.text,
"Token" => document.css("SessionToken").children.text,
"Expiration" => document.css("Expiration").children.text,
}
if region.nil?
connection = options[:metadata_connection] || Excon.new(INSTANCE_METADATA_HOST)
token_header = fetch_credentials_token_header(connection, options[:disable_imds_v2])
region = connection.get(:path => INSTANCE_METADATA_AZ, :idempotent => true, :expects => 200, :headers => token_header).body[0..-2]
end
else
connection = options[:connection] || Excon.new(INSTANCE_METADATA_HOST)
token_header = fetch_credentials_token_header(connection, options[:disable_imds_v2])
role_name = connection.get(:path => INSTANCE_METADATA_PATH, :idempotent => true, :expects => 200, :headers => token_header).body
role_data = connection.get(:path => INSTANCE_METADATA_PATH+role_name, :idempotent => true, :expects => 200, :headers => token_header).body
session = Fog::JSON.decode(role_data)
region ||= connection.get(:path => INSTANCE_METADATA_AZ, :idempotent => true, :expects => 200, :headers => token_header).body[0..-2]
end
credentials = {}
credentials[:aws_access_key_id] = session['AccessKeyId']
credentials[:aws_secret_access_key] = session['SecretAccessKey']
credentials[:aws_session_token] = session['Token']
credentials[:aws_credentials_expire_at] = Time.xmlschema session['Expiration']
# set region by default to the one the instance is in.
credentials[:region] = region
credentials[:sts_endpoint] = sts_endpoint if sts_endpoint
#these indicate the metadata service is unavailable or has no profile setup
credentials
rescue Excon::Error => e
Fog::Logger.warning("Unable to fetch credentials: #{e.message}")
super
end
else
super
end
end
def fetch_credentials_token_header(connection, disable_imds_v2)
return nil if disable_imds_v2
token = connection.put(
:path => INSTANCE_METADATA_TOKEN,
:idempotent => true,
:expects => 200,
:retry_interval => 1,
:retry_limit => 3,
:read_timeout => 1,
:write_timeout => 1,
:connect_timeout => 1,
:headers => { "X-aws-ec2-metadata-token-ttl-seconds" => "300" }
).body
{ "X-aws-ec2-metadata-token" => token }
rescue Excon::Error
nil
end
end
module ConnectionMethods
def refresh_credentials_if_expired
refresh_credentials if credentials_expired?
end
private
# When defined, 'aws_credentials_refresh_threshold_seconds' controls
# when the credential needs to be refreshed, expressed in seconds before
# the current credential's expiration time
def credentials_refresh_threshold
@aws_credentials_refresh_threshold_seconds || 15
end
def credentials_expired?
@use_iam_profile &&
(!@aws_credentials_expire_at ||
(@aws_credentials_expire_at && Fog::Time.now > @aws_credentials_expire_at - credentials_refresh_threshold)) #new credentials become available from around 5 minutes before expiration time
end
def refresh_credentials
if @use_iam_profile
new_credentials = service.fetch_credentials :use_iam_profile => @use_iam_profile, :region => @region
if new_credentials.any?
setup_credentials new_credentials
return true
else
false
end
else
false
end
end
end
end
end
end
|
