[AuthenticationMixin] authentication_status to virtual_delegate

Creates a virtual_delegate for AuthenticationMixin#authentication_status
which allows it to be included in reports and put in as part of the main
query.

The biggest thing of note in this change is how the status_severity_arel
is being used to handle the sorting properly in the SQL query.  It makes
use of a SQL's case statement to handle what would normally be a
`sort_by` on the hash lookup of Authentication::STATUS_SEVERITY.
Instead, we match each key to the status column and use that as the
value for the `ORDER BY exp DESC` in the `has_one`, which allows for the
same affect.

This also means that it can inject itself in the `SELECT` of a
`MiqReport`, and avoid N+1's on things like quadicons and such for pages
that use `MiqReport#paged_view_search`.

app/models/authentication.rb

@@ -55,6 +55,22 @@ def self.new(*args, &block)
  "invalid" => 3,
  ).freeze
 
+ # Builds a case statement that case be used in a sql ORDER BY.
+ #
+ # Generated SQL looks like:
+ #
+ # CASE
+ # WHEN LOWER(status) = '' THEN -1
+ # WHEN LOWER(status) = 'valid' THEN 0
+ # ...
+ # ELSE -1
+ #
+ STATUS_SEVERITY_AREL = Arel::Nodes::Case.new.tap do |arel_case|
+ STATUS_SEVERITY.each do |value, sort_weight|
+ arel_case.when(arel_table[:status].lower.eq(value)).then(sort_weight)
+ end
+ end.else(-1)
+
  RETRYABLE_STATUS = %w(error unreachable).freeze
 
  CREDENTIAL_TYPES = {

app/models/mixins/authentication_mixin.rb

@@ -4,7 +4,16 @@ module AuthenticationMixin
  included do
  has_many :authentications, :as => :resource, :dependent => :destroy, :autosave => true
 
- virtual_column :authentication_status, :type => :string
+ has_one :authentication_status_severity_level,
+ -> { order(Authentication::STATUS_SEVERITY_AREL.desc) },
+ :as => :resource,
+ :inverse_of => :resource,
+ :class_name => "Authentication"
+
+ virtual_delegate :authentication_status,
+ :to => "authentication_status_severity_level.status",
+ :default => "None",
+ :allow_nil => true
 
  def self.authentication_check_schedule
  zone = MiqServer.my_server.zone
@@ -117,11 +126,6 @@ def missing_credentials?(type = nil)
  !has_credentials?(type)
  end
 
- def authentication_status
- ordered_auths = authentication_for_providers.sort_by(&:status_severity)
- ordered_auths.last.try(:status) || "None"
- end
-
  def authentication_status_ok?(type = nil)
  authentication_best_fit(type).try(:status) == "Valid"
  end

spec/models/mixins/authentication_mixin_spec.rb

@@ -1,4 +1,11 @@
 describe AuthenticationMixin do
+ include Spec::Support::ArelHelper
+
+ let(:host) { FactoryGirl.create(:host) }
+ let(:invalid_auth) { FactoryGirl.create(:authentication, :resource => host, :status => "Invalid") }
+ let(:valid_auth) { FactoryGirl.create(:authentication, :resource => host, :status => "Valid") }
+ let(:authentications) { [invalid_auth, valid_auth] }
+
  let(:test_class_instance) do
  Class.new(ActiveRecord::Base) do
  def self.name; "TestClass"; end
@@ -721,4 +728,76 @@ def self.name; "TestClass"; end
  end
  end
  end
+
+ describe "#authentication_status_severity_level" do
+ it "uses the least valid status" do
+ EvmSpecHelper.local_miq_server
+ authentications
+ expect(host.authentication_status_severity_level.status).to eq("Invalid")
+ end
+ end
+
+ describe "#authentication_status" do
+ before do
+ EvmSpecHelper.local_miq_server
+ end
+
+ context "with no authentications" do
+ before { host }
+
+ it "is nil with sql" do
+ expect(virtual_column_sql_value(Host, "authentication_status")).to be_nil
+ end
+
+ it "is 'None' with pure ruby (via relations)" do
+ expect(host.authentication_status).to eq("None")
+ end
+
+ it "is 'None' when accessed via ruby, but fetched via sql" do
+ fetched_host = Host.select(:id, :authentication_status).first
+ expect(fetched_host.attributes[:authentication_status]).to be_nil
+ expect(fetched_host.authentication_status).to eq("None")
+ end
+ end
+
+ context "with a valid authentication" do
+ before { valid_auth }
+
+ it "is 'Valid' with sql" do
+ h = Host.select(:id, :authentication_status).first
+
+ expect do
+ expect(h.authentication_status).to eq("Valid")
+ end.to match_query_limit_of(0)
+ expect(h.association(:authentication_status_severity_level)).not_to be_loaded
+ end
+
+ it "is 'Valid' with ruby" do
+ h = Host.first # clean host record
+
+ expect(h.authentication_status).to eq("Valid")
+ expect(h.association(:authentication_status_severity_level)).to be_loaded
+ end
+ end
+
+ context "with a valid and invalid authentication" do
+ before { authentications }
+
+ it "is 'Invalid' with sql" do
+ h = Host.select(:id, :authentication_status).first
+
+ expect do
+ expect(h.authentication_status).to eq("Invalid")
+ end.to match_query_limit_of(0)
+ expect(h.association(:authentication_status_severity_level)).not_to be_loaded
+ end
+
+ it "is 'Valid' with ruby" do
+ h = Host.first # clean host record
+
+ expect(h.authentication_status).to eq("Invalid")
+ expect(h.association(:authentication_status_severity_level)).to be_loaded
+ end
+ end
+ end
 end