109 lines
4.4 KiB
Ruby
109 lines
4.4 KiB
Ruby
# Copyright 2015, Google Inc.
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# All rights reserved.
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#
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions are
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# met:
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#
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# * Redistributions of source code must retain the above copyright
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# notice, this list of conditions and the following disclaimer.
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# * Redistributions in binary form must reproduce the above
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# copyright notice, this list of conditions and the following disclaimer
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# in the documentation and/or other materials provided with the
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# distribution.
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# * Neither the name of Google Inc. nor the names of its
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# contributors may be used to endorse or promote products derived from
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# this software without specific prior written permission.
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#
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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require 'faraday'
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require 'googleauth/signet'
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require 'memoist'
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module Google
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# Module Auth provides classes that provide Google-specific authorization
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# used to access Google APIs.
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module Auth
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NO_METADATA_SERVER_ERROR = <<ERROR.freeze
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Error code 404 trying to get security access token
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from Compute Engine metadata for the default service account. This
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may be because the virtual machine instance does not have permission
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scopes specified.
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ERROR
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UNEXPECTED_ERROR_SUFFIX = <<ERROR.freeze
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trying to get security access token from Compute Engine metadata for
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the default service account
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ERROR
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# Extends Signet::OAuth2::Client so that the auth token is obtained from
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# the GCE metadata server.
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class GCECredentials < Signet::OAuth2::Client
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# The IP Address is used in the URIs to speed up failures on non-GCE
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# systems.
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COMPUTE_AUTH_TOKEN_URI = 'http://169.254.169.254/computeMetadata/v1/'\
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'instance/service-accounts/default/token'.freeze
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COMPUTE_CHECK_URI = 'http://169.254.169.254'.freeze
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class << self
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extend Memoist
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# Detect if this appear to be a GCE instance, by checking if metadata
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# is available
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def on_gce?(options = {})
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c = options[:connection] || Faraday.default_connection
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resp = c.get(COMPUTE_CHECK_URI) do |req|
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# Comment from: oauth2client/client.py
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#
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# Note: the explicit `timeout` below is a workaround. The underlying
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# issue is that resolving an unknown host on some networks will take
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# 20-30 seconds; making this timeout short fixes the issue, but
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# could lead to false negatives in the event that we are on GCE, but
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# the metadata resolution was particularly slow. The latter case is
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# "unlikely".
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req.options.timeout = 0.1
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end
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return false unless resp.status == 200
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return false unless resp.headers.key?('Metadata-Flavor')
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return resp.headers['Metadata-Flavor'] == 'Google'
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rescue Faraday::TimeoutError, Faraday::ConnectionFailed
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return false
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end
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memoize :on_gce?
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end
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# Overrides the super class method to change how access tokens are
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# fetched.
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def fetch_access_token(options = {})
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c = options[:connection] || Faraday.default_connection
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retry_with_error do
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headers = { 'Metadata-Flavor' => 'Google' }
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resp = c.get(COMPUTE_AUTH_TOKEN_URI, nil, headers)
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case resp.status
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when 200
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Signet::OAuth2.parse_credentials(resp.body,
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resp.headers['content-type'])
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when 404
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raise(Signet::AuthorizationError, NO_METADATA_SERVER_ERROR)
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else
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msg = "Unexpected error code #{resp.status}" \
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"#{UNEXPECTED_ERROR_SUFFIX}"
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raise(Signet::AuthorizationError, msg)
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end
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end
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end
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end
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end
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end
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