Refactor service_state and add queries

- Refactor service_state to be a read_only attribute
- Rename old service_state method to get_service_state
- Refactor rspecs associated to old service_state method
- Add method queries for service state via metaprogramming with an array
  whose position indicates the return code
- Add rspec tests for the service state method queries

Signed-off-by: Robert Marshall <rmarshall@gitlab.com>

files/gitlab-cookbooks/gitlab/libraries/helpers/base_pg_helper.rb

@@ -5,6 +5,7 @@ require_relative '../pg_version'
 class BasePgHelper < BaseHelper
   include ShellOutHelper
   attr_reader :node
+  attr_reader :service_state
   PG_HASH_PATTERN ||= /\{(.*)\}/.freeze
   PG_HASH_PAIR_SEPARATOR ||= ','.freeze
@@ -18,7 +19,18 @@ class BasePgHelper < BaseHelper
     omnibus_helper.service_up?(service_name) || (delegated? && omnibus_helper.service_up?(delegate_service_name) && ready?)
   end
-  def service_state
+  [
+    'accepting_connections?',
+    'rejecting_connections?',
+    'not_responding?',
+    'invalid_connection_parameters?'
+  ].each.with_index do |method, index|
+    define_method method do
+      get_service_state == index
+    end
+  end
+
+  def get_service_state
     bin = "#{node['package']['install-dir']}/embedded/bin/pg_isready"
     dbname = node['gitlab']['gitlab-rails']['db_database']
     dbhost = node['postgresql']['unix_socket_directory']
@@ -27,7 +39,7 @@ class BasePgHelper < BaseHelper
     cmd = %W(#{bin} -d #{dbname} -h #{dbhost} -p #{port} -U #{pguser})
-    do_shell_out(cmd).exitstatus
+    @service_state = do_shell_out(cmd).exitstatus
   end
   def is_managed_and_offline?

spec/libraries/helpers/base_pg_helper_spec.rb

@@ -135,18 +135,6 @@ RSpec.describe BasePgHelper do
     end
   end
-  describe '#service_state' do
-    before do
-      result = spy('shellout')
-      allow(result).to receive(:exitstatus).and_return(42)
-      allow(subject).to receive(:do_shell_out).and_return(result)
-    end
-
-    it 'returns an exit status from pg_isready' do
-      expect(subject.service_state).to eq(42)
-    end
-  end
-
   describe '#user_options' do
     before do
       result = spy('shellout')
@@ -326,4 +314,62 @@ RSpec.describe BasePgHelper do
       expect(subject.is_standby?).to be false
     end
   end
+
+  context 'when checking the connection to PostgreSQL' do
+    describe '#service_state' do
+      it 'returns an exit status from pg_isready' do
+        result = spy('shellout')
+        allow(subject).to receive(:do_shell_out).and_return(result)
+        allow(result).to receive(:exitstatus).and_return(42)
+        expect(subject.get_service_state).to eq(42)
+      end
+    end
+
+    context 'when invoking pg_isready' do
+      using RSpec::Parameterized::TableSyntax
+
+      where(:exit_code, :accepting, :rejecting, :not_responding, :invalid_parameters) do
+        0 | true | false | false | false
+        1 | false | true | false | false
+        2 | false | false | true | false
+        3 | false | false | false | true
+      end
+
+      with_them do
+        before do
+          result = spy('shellout')
+          allow(subject).to receive(:do_shell_out).and_return(result)
+          allow(result).to receive(:exitstatus).and_return(exit_code)
+        end
+
+        it 'returns the last service state checked' do
+          expect { subject.get_service_state }.to change { subject.service_state }.from(nil).to(exit_code)
+        end
+
+        describe '#accepting_connections?' do
+          it 'returns the expected boolean' do
+            expect(subject.accepting_connections?).to be accepting
+          end
+        end
+
+        describe '#rejecting_connections?' do
+          it 'returns the expected boolean' do
+            expect(subject.rejecting_connections?).to be rejecting
+          end
+        end
+
+        describe '#not_responding?' do
+          it 'returns the expected boolean' do
+            expect(subject.not_responding?).to be not_responding
+          end
+        end
+
+        describe '#invalid_connection_parameters?' do
+          it 'returns the expected boolean' do
+            expect(subject.invalid_connection_parameters?).to be invalid_parameters
+          end
+        end
+      end
+    end
+  end
 end