Refactoring: move the credentials load into its own class

This commit is contained in:
Tim Emiola 2015-03-06 13:13:26 -08:00
parent a2b59eb836
commit df56f8af33
4 changed files with 107 additions and 66 deletions

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@ -0,0 +1,85 @@
# Copyright 2015, Google Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
# * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
require 'memoist'
require 'rbconfig'
module Google
# Module Auth provides classes that provide Google-specific authorization
# used to access Google APIs.
module Auth
# CredentialsLoader contains the behaviour used to locate and find default
# credentials files on the file system.
module CredentialsLoader
extend Memoist
ENV_VAR = 'GOOGLE_APPLICATION_CREDENTIALS'
NOT_FOUND_ERROR =
"Unable to read the credential file specified by #{ENV_VAR}"
WELL_KNOWN_PATH = 'gcloud/application_default_credentials.json'
WELL_KNOWN_ERROR = 'Unable to read the default credential file'
# determines if the current OS is windows
def windows?
RbConfig::CONFIG['host_os'] =~ /Windows|mswin/
end
memoize :windows?
# Creates an instance from the path specified in an environment
# variable.
#
# @param scope [string|array] the scope(s) to access
def from_env(scope)
return nil unless ENV.key?(ENV_VAR)
path = ENV[ENV_VAR]
fail 'file #{path} does not exist' unless File.exist?(path)
File.open(path) do |f|
return new(scope, f)
end
rescue StandardError => e
raise "#{NOT_FOUND_ERROR}: #{e}"
end
# Creates an instance from a well known path.
#
# @param scope [string|array] the scope(s) to access
def from_well_known_path(scope)
home_var, base = windows? ? 'APPDATA' : 'HOME', WELL_KNOWN_PATH
root = ENV[home_var].nil? ? '' : ENV[home_var]
base = File.join('.config', base) unless windows?
path = File.join(root, base)
return nil unless File.exist?(path)
File.open(path) do |f|
return new(scope, f)
end
rescue StandardError => e
raise "#{WELL_KNOWN_ERROR}: #{e}"
end
end
end
end

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@ -28,18 +28,8 @@
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
require 'googleauth/signet'
require 'memoist'
require 'googleauth/credentials_loader'
require 'multi_json'
require 'openssl'
require 'rbconfig'
# Reads the private key and client email fields from service account JSON key.
def read_json_key(json_key_io)
json_key = MultiJson.load(json_key_io.read)
fail 'missing client_email' unless json_key.key?('client_email')
fail 'missing private_key' unless json_key.key?('private_key')
[json_key['private_key'], json_key['client_email']]
end
module Google
# Module Auth provides classes that provide Google-specific authorization
@ -53,52 +43,16 @@ module Google
#
# cf [Application Default Credentials](http://goo.gl/mkAHpZ)
class ServiceAccountCredentials < Signet::OAuth2::Client
ENV_VAR = 'GOOGLE_APPLICATION_CREDENTIALS'
NOT_FOUND_ERROR =
"Unable to read the credential file specified by #{ENV_VAR}"
TOKEN_CRED_URI = 'https://www.googleapis.com/oauth2/v3/token'
WELL_KNOWN_PATH = 'gcloud/application_default_credentials.json'
WELL_KNOWN_ERROR = 'Unable to read the default credential file'
extend CredentialsLoader
class << self
extend Memoist
# determines if the current OS is windows
def windows?
RbConfig::CONFIG['host_os'] =~ /Windows|mswin/
end
memoize :windows?
# Creates an instance from the path specified in an environment
# variable.
#
# @param scope [string|array] the scope(s) to access
def from_env(scope)
return nil unless ENV.key?(ENV_VAR)
path = ENV[ENV_VAR]
fail 'file #{path} does not exist' unless File.exist?(path)
File.open(path) do |f|
return new(scope, f)
end
rescue StandardError => e
raise "#{NOT_FOUND_ERROR}: #{e}"
end
# Creates an instance from a well known path.
#
# @param scope [string|array] the scope(s) to access
def from_well_known_path(scope)
home_var, base = windows? ? 'APPDATA' : 'HOME', WELL_KNOWN_PATH
root = ENV[home_var].nil? ? '' : ENV[home_var]
base = File.join('.config', base) unless windows?
path = File.join(root, base)
return nil unless File.exist?(path)
File.open(path) do |f|
return new(scope, f)
end
rescue StandardError => e
raise "#{WELL_KNOWN_ERROR}: #{e}"
end
# Reads the private key and client email fields from the service account
# JSON key.
def self.read_json_key(json_key_io)
json_key = MultiJson.load(json_key_io.read)
fail 'missing client_email' unless json_key.key?('client_email')
fail 'missing private_key' unless json_key.key?('private_key')
[json_key['private_key'], json_key['client_email']]
end
# Initializes a ServiceAccountCredentials.
@ -106,9 +60,9 @@ module Google
# @param scope [string|array] the scope(s) to access
# @param json_key_io [IO] an IO from which the JSON key can be read
def initialize(scope, json_key_io)
private_key, client_email = read_json_key(json_key_io)
private_key, client_email = self.class.read_json_key(json_key_io)
super(token_credential_uri: TOKEN_CRED_URI,
audience: TOKEN_CRED_URI, # TODO: confirm this
audience: TOKEN_CRED_URI,
scope: scope,
issuer: client_email,
signing_key: OpenSSL::PKey::RSA.new(private_key))

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@ -38,7 +38,7 @@ require 'spec_helper'
describe '#get_application_default' do
before(:example) do
@key = OpenSSL::PKey::RSA.new(2048)
@var_name = ServiceAccountCredentials::ENV_VAR
@var_name = CredentialsLoader::ENV_VAR
@orig = ENV[@var_name]
@home = ENV['HOME']
@scope = 'https://www.googleapis.com/auth/userinfo.profile'
@ -82,7 +82,7 @@ describe '#get_application_default' do
ENV.delete(@var_name) unless ENV[@var_name].nil?
Dir.mktmpdir do |dir|
key_path = File.join(dir, '.config',
ServiceAccountCredentials::WELL_KNOWN_PATH)
CredentialsLoader::WELL_KNOWN_PATH)
FileUtils.mkdir_p(File.dirname(key_path))
File.write(key_path, cred_json_text)
ENV['HOME'] = dir

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@ -42,6 +42,7 @@ require 'tmpdir'
describe Google::Auth::ServiceAccountCredentials do
ServiceAccountCredentials = Google::Auth::ServiceAccountCredentials
CredentialsLoader = Google::Auth::CredentialsLoader
before(:example) do
@key = OpenSSL::PKey::RSA.new(2048)
@ -79,9 +80,10 @@ describe Google::Auth::ServiceAccountCredentials do
describe '#from_env' do
before(:example) do
@var_name = ServiceAccountCredentials::ENV_VAR
@var_name = CredentialsLoader::ENV_VAR
@orig = ENV[@var_name]
@scope = 'https://www.googleapis.com/auth/userinfo.profile'
@clz = ServiceAccountCredentials
end
after(:example) do
@ -99,18 +101,17 @@ describe Google::Auth::ServiceAccountCredentials do
Dir.mktmpdir do |dir|
key_path = File.join(dir, 'does-not-exist')
ENV[@var_name] = key_path
expect { sac.from_env(@scope) }.to raise_error
expect { @clz.from_env(@scope) }.to raise_error
end
end
it 'succeeds when the GOOGLE_APPLICATION_CREDENTIALS file is valid' do
sac = ServiceAccountCredentials # shortens name
Dir.mktmpdir do |dir|
key_path = File.join(dir, 'my_cert_file')
FileUtils.mkdir_p(File.dirname(key_path))
File.write(key_path, cred_json_text)
ENV[@var_name] = key_path
expect(sac.from_env(@scope)).to_not be_nil
expect(@clz.from_env(@scope)).to_not be_nil
end
end
end
@ -119,6 +120,8 @@ describe Google::Auth::ServiceAccountCredentials do
before(:example) do
@home = ENV['HOME']
@scope = 'https://www.googleapis.com/auth/userinfo.profile'
@known_path = CredentialsLoader::WELL_KNOWN_PATH
@clz = ServiceAccountCredentials
end
after(:example) do
@ -131,13 +134,12 @@ describe Google::Auth::ServiceAccountCredentials do
end
it 'successfully loads the file when it is present' do
sac = ServiceAccountCredentials # shortens name
Dir.mktmpdir do |dir|
key_path = File.join(dir, '.config', sac::WELL_KNOWN_PATH)
key_path = File.join(dir, '.config', @known_path)
FileUtils.mkdir_p(File.dirname(key_path))
File.write(key_path, cred_json_text)
ENV['HOME'] = dir
expect(sac.from_well_known_path(@scope)).to_not be_nil
expect(@clz.from_well_known_path(@scope)).to_not be_nil
end
end
end