Pulls file credentials parsing out of Azure class

lib/train/transports/azure.rb

@@ -3,9 +3,9 @@
 require 'train/plugins'
 require 'ms_rest_azure'
 require 'azure_mgmt_resources'
-require 'inifile'
 require 'socket'
 require 'timeout'
+require 'train/transports/helpers/azure/file_credentials'
 
 module Train::Transports
   class Azure < Train.plugin(1)
@@ -23,7 +23,7 @@ def connection(_ = nil)
       @connection ||= Connection.new(@options)
     end
 
-    class Connection < BaseConnection # rubocop:disable Metrics/ClassLength
+    class Connection < BaseConnection
       attr_reader :options
 
       def initialize(options)
@@ -38,7 +38,7 @@ def initialize(options)
         @cache[:api_call] = {}
 
         if @options[:client_secret].nil? && @options[:client_id].nil?
-          parse_credentials_file
+          @options.merge!(Helpers::Azure::FileCredentials.parse(@options))
         end
 
         @options[:msi_port] = @options[:msi_port].to_i unless @options[:msi_port].nil?
@@ -149,40 +149,6 @@ def port_open?(port, seconds = 1)
       rescue Timeout::Error
         false
       end
-
-      def parse_credentials_file # rubocop:disable Metrics/AbcSize
-        # If an AZURE_CRED_FILE environment variable has been specified set the
-        # the credentials file to that, otherwise set the one in home
-        azure_creds_file = @options[:credentials_file]
-        azure_creds_file = File.join(Dir.home, '.azure', 'credentials') if azure_creds_file.nil?
-        return unless File.readable?(azure_creds_file)
-
-        credentials = IniFile.load(File.expand_path(azure_creds_file))
-        if @options[:subscription_id]
-          id = @options[:subscription_id]
-        elsif !ENV['AZURE_SUBSCRIPTION_NUMBER'].nil?
-          subscription_number = ENV['AZURE_SUBSCRIPTION_NUMBER'].to_i
-
-          # Check that the specified index is not greater than the number of subscriptions
-          if subscription_number > credentials.sections.length
-            raise format(
-              'Your credentials file only contains %s subscriptions.  You specified number %s.',
-              @credentials.sections.length,
-              subscription_number,
-            )
-          end
-          id = credentials.sections[subscription_number - 1]
-        else
-          raise 'Multiple credentials detected, please set the AZURE_SUBSCRIPTION_ID environment variable.' if credentials.sections.count > 1
-          id = credentials.sections[0]
-        end
-
-        raise "No credentials found for subscription number #{id}" if credentials.sections.empty? || credentials[id].empty?
-        @options[:subscription_id] = id
-        @options[:tenant_id] = credentials[id]['tenant_id']
-        @options[:client_id] = credentials[id]['client_id']
-        @options[:client_secret] = credentials[id]['client_secret']
-      end
     end
   end
 end

lib/train/transports/helpers/azure/file_credentials.rb

@@ -0,0 +1,42 @@
+# encoding: utf-8
+
+require 'inifile'
+require 'train/transports/helpers/azure/file_parser'
+require 'train/transports/helpers/azure/subscription_number_file_parser'
+require 'train/transports/helpers/azure/subscription_id_file_parser'
+
+module Train::Transports
+  module Helpers
+    module Azure
+      class FileCredentials
+        DEFAULT_FILE = ::File.join(Dir.home, '.azure', 'credentials')
+
+        def self.parse(subscription_id: nil, credentials_file: DEFAULT_FILE, **_)
+          return {} unless ::File.readable?(credentials_file)
+          credentials     = IniFile.load(::File.expand_path(credentials_file))
+          subscription_id = parser(subscription_id, ENV['AZURE_SUBSCRIPTION_NUMBER'], credentials).subscription_id
+          creds(subscription_id, credentials)
+        end
+
+        def self.parser(subscription_id, subscription_number, credentials)
+          if subscription_id
+            SubscriptionIdFileParser.new(subscription_id, credentials)
+          elsif !subscription_number.nil?
+            SubscriptionNumberFileParser.new(subscription_number.to_i, credentials)
+          else
+            FileParser.new(credentials)
+          end
+        end
+
+        def self.creds(subscription_id, credentials)
+          {
+            subscription_id: subscription_id,
+            tenant_id:       credentials[subscription_id]['tenant_id'],
+            client_id:       credentials[subscription_id]['client_id'],
+            client_secret:   credentials[subscription_id]['client_secret'],
+          }
+        end
+      end
+    end
+  end
+end

lib/train/transports/helpers/azure/file_parser.rb

@@ -0,0 +1,25 @@
+# encoding: utf-8
+
+module Train::Transports
+  module Helpers
+    module Azure
+      class FileParser
+        def initialize(credentials)
+          @credentials = credentials
+
+          validate!
+        end
+
+        def validate!
+          return if @credentials.sections.count == 1
+
+          raise 'Credentials file must have one entry. Check your credentials file. If you have more than one entry set AZURE_SUBSCRIPTION_ID environment variable.'
+        end
+
+        def subscription_id
+          @subscription_id ||= @credentials.sections[0]
+        end
+      end
+    end
+  end
+end

lib/train/transports/helpers/azure/subscription_id_file_parser.rb

@@ -0,0 +1,24 @@
+# encoding: utf-8
+
+module Train::Transports
+  module Helpers
+    module Azure
+      class SubscriptionIdFileParser
+        attr_reader :subscription_id
+
+        def initialize(subscription_id, credentials)
+          @subscription_id = subscription_id
+          @credentials     = credentials
+
+          validate!
+        end
+
+        def validate!
+          if @credentials.sections.empty? || @credentials[subscription_id].empty?
+            raise "No credentials found for subscription number #{subscription_id}"
+          end
+        end
+      end
+    end
+  end
+end

lib/train/transports/helpers/azure/subscription_number_file_parser.rb

@@ -0,0 +1,30 @@
+# encoding: utf-8
+
+module Train::Transports
+  module Helpers
+    module Azure
+      class SubscriptionNumberFileParser
+        def initialize(index, credentials)
+          @index       = index
+          @credentials = credentials
+
+          validate!
+        end
+
+        def validate!
+          if @index == 0
+            raise 'Index must be greater than 0.'
+          end
+
+          if @index > @credentials.sections.length
+            raise "Your credentials file only contains #{@credentials.sections.length} subscriptions. You specified number #{@index}."
+          end
+        end
+
+        def subscription_id
+          @subscription_id ||= @credentials.sections[@index - 1]
+        end
+      end
+    end
+  end
+end

test/unit/transports/azure_test.rb

@@ -122,59 +122,4 @@ def initialize(hash)
       connection.unique_identifier.must_equal 'test_tenant_id'
     end
   end
-
-  describe 'parse_credentials_file' do
-    let(:cred_file) do
-      require 'tempfile'
-      file = Tempfile.new('cred_file')
-      info = <<-INFO
-        [my_subscription_id]
-        client_id = "my_client_id"
-        client_secret = "my_client_secret"
-        tenant_id = "my_tenant_id"
-
-        [my_subscription_id2]
-        client_id = "my_client_id2"
-        client_secret = "my_client_secret2"
-        tenant_id = "my_tenant_id2"
-      INFO
-      file.write(info)
-      file.close
-      file
-    end
-
-    it 'validate credentials from file' do
-      options[:credentials_file] = cred_file.path
-      options[:subscription_id] = 'my_subscription_id'
-      connection.send(:parse_credentials_file)
-
-      options[:tenant_id].must_equal 'my_tenant_id'
-      options[:client_id].must_equal 'my_client_id'
-      options[:client_secret].must_equal 'my_client_secret'
-      options[:subscription_id].must_equal 'my_subscription_id'
-    end
-
-    it 'validate credentials from file subscription override' do
-      options[:credentials_file] = cred_file.path
-      options[:subscription_id] = 'my_subscription_id2'
-      connection.send(:parse_credentials_file)
-
-      options[:tenant_id].must_equal 'my_tenant_id2'
-      options[:client_id].must_equal 'my_client_id2'
-      options[:client_secret].must_equal 'my_client_secret2'
-      options[:subscription_id].must_equal 'my_subscription_id2'
-    end
-
-    it 'validate credentials from file subscription index' do
-      options[:credentials_file] = cred_file.path
-      options[:subscription_id] = nil
-      ENV['AZURE_SUBSCRIPTION_NUMBER'] = '2'
-      connection.send(:parse_credentials_file)
-
-      options[:tenant_id].must_equal 'my_tenant_id2'
-      options[:client_id].must_equal 'my_client_id2'
-      options[:client_secret].must_equal 'my_client_secret2'
-      options[:subscription_id].must_equal 'my_subscription_id2'
-    end
-  end
 end

test/unit/transports/helpers/azure/file_credentials_test.rb

@@ -0,0 +1,121 @@
+# encoding: utf-8
+
+require 'helper'
+require 'tempfile'
+require 'train/transports/helpers/azure/file_credentials'
+
+describe 'parse_credentials_file' do
+  let(:cred_file_single_entry) do
+    file = Tempfile.new('cred_file')
+    info = <<-INFO
+      [my_subscription_id]
+      client_id = "my_client_id"
+      client_secret = "my_client_secret"
+      tenant_id = "my_tenant_id"
+    INFO
+    file.write(info)
+    file.close
+    file
+  end
+
+  let(:cred_file_multiple_entries) do
+    file = Tempfile.new('cred_file')
+    info = <<-INFO
+      [my_subscription_id]
+      client_id = "my_client_id"
+      client_secret = "my_client_secret"
+      tenant_id = "my_tenant_id"
+
+      [my_subscription_id2]
+      client_id = "my_client_id2"
+      client_secret = "my_client_secret2"
+      tenant_id = "my_tenant_id2"
+    INFO
+    file.write(info)
+    file.close
+    file
+  end
+
+  let(:options) { { credentials_file: cred_file_multiple_entries.path } }
+
+  it 'returns empty hash when no credentials file detected' do
+    result = Train::Transports::Helpers::Azure::FileCredentials.parse({})
+
+    assert_empty(result)
+  end
+
+  it 'loads only entry from file when no subscription id given' do
+    options[:credentials_file] = cred_file_single_entry.path
+
+    result = Train::Transports::Helpers::Azure::FileCredentials.parse(options)
+
+    assert_equal('my_tenant_id',       result[:tenant_id])
+    assert_equal('my_client_id',       result[:client_id])
+    assert_equal('my_client_secret',   result[:client_secret])
+    assert_equal('my_subscription_id', result[:subscription_id])
+  end
+
+  it 'raises an error when no subscription id given and multiple entries' do
+    error = assert_raises RuntimeError do
+      Train::Transports::Helpers::Azure::FileCredentials.parse(options)
+    end
+
+    assert_equal('Credentials file must have one entry. Check your credentials file. If you have more than one entry set AZURE_SUBSCRIPTION_ID environment variable.', error.message)
+  end
+
+  it 'loads entry when subscription id is given' do
+    options[:subscription_id] = 'my_subscription_id'
+
+    result = Train::Transports::Helpers::Azure::FileCredentials.parse(options)
+
+    assert_equal('my_tenant_id',       result[:tenant_id])
+    assert_equal('my_client_id',       result[:client_id])
+    assert_equal('my_client_secret',   result[:client_secret])
+    assert_equal('my_subscription_id', result[:subscription_id])
+  end
+
+  it 'raises an error when subscription id not found' do
+    options[:subscription_id] = 'missing_subscription_id'
+
+    error = assert_raises RuntimeError do
+      Train::Transports::Helpers::Azure::FileCredentials.parse(options)
+    end
+
+    assert_equal('No credentials found for subscription number missing_subscription_id', error.message)
+  end
+
+  it 'loads entry based on index' do
+    ENV['AZURE_SUBSCRIPTION_NUMBER'] = '2'
+
+    result = Train::Transports::Helpers::Azure::FileCredentials.parse(options)
+
+    ENV.delete('AZURE_SUBSCRIPTION_NUMBER')
+
+    assert_equal('my_tenant_id2',       result[:tenant_id])
+    assert_equal('my_client_id2',       result[:client_id])
+    assert_equal('my_client_secret2',   result[:client_secret])
+    assert_equal('my_subscription_id2', result[:subscription_id])
+  end
+
+  it 'raises an error when index is out of bounds' do
+    ENV['AZURE_SUBSCRIPTION_NUMBER'] = '3'
+
+    error = assert_raises RuntimeError do
+      Train::Transports::Helpers::Azure::FileCredentials.parse(options)
+    end
+    ENV.delete('AZURE_SUBSCRIPTION_NUMBER')
+
+    assert_equal('Your credentials file only contains 2 subscriptions. You specified number 3.', error.message)
+  end
+
+  it 'raises an error when index 0 is given' do
+    ENV['AZURE_SUBSCRIPTION_NUMBER'] = '0'
+
+    error = assert_raises RuntimeError do
+      Train::Transports::Helpers::Azure::FileCredentials.parse(options)
+    end
+    ENV.delete('AZURE_SUBSCRIPTION_NUMBER')
+
+    assert_equal('Index must be greater than 0.', error.message)
+  end
+end