diff --git a/.rubocop.yml b/.rubocop.yml
index 8acea7a..f6799cd 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -9,7 +9,6 @@ AllCops:
   TargetRubyVersion: 3.0
   Exclude:
     - bin/*
-    - spec/**/*
 
 Gemspec/RequireMFA:
   Enabled: false
@@ -24,15 +23,41 @@ Style/Documentation:
 Style/RedundantBegin:
   Enabled: false
 
+Style/BlockDelimiters:
+  AllowedPatterns: ['expect']
+
 ##########
 # LAYOUT #
 ##########
 
-Layout/EmptyLinesAroundModuleBody:
+Layout/LineLength:
+  Max: 125
+
+Layout/EmptyLines:
+  Enabled: false
+
+Layout/EmptyLineBetweenDefs:
   Enabled: false
 
 Layout/EmptyLinesAroundClassBody:
   Enabled: false
 
-Layout/LineLength:
-  Max: 125
+Layout/EmptyLinesAroundBlockBody:
+  Enabled: false
+
+Layout/EmptyLinesAroundModuleBody:
+  Enabled: false
+
+Layout/HashAlignment:
+  EnforcedColonStyle: table
+  EnforcedHashRocketStyle: table
+
+#########
+# RSPEC #
+#########
+
+RSpec/MultipleExpectations:
+  Max: 3
+
+RSpec/ExampleLength:
+  Max: 8
diff --git a/spec/icinga2/api/downtime_spec.rb b/spec/icinga2/api/downtime_spec.rb
index f3e11ba..fe059a4 100644
--- a/spec/icinga2/api/downtime_spec.rb
+++ b/spec/icinga2/api/downtime_spec.rb
@@ -1,10 +1,10 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Icinga2::API::Downtime do
 
-  let(:client) { Icinga2::API::Client.new('https://icinga2.example.net:5665', icinga_credentials) }
-
-  subject do
+  subject(:downtime) do
     create_downtime('foo.example.net', 'dockerd|daemon')
     client.hosts
           .find('foo.example.net')
@@ -14,34 +14,36 @@
           .first
   end
 
+  let(:client) { Icinga2::API::Client.new('https://icinga2.example.net:5665', icinga_credentials) }
+
   describe '#api_client' do
-    it 'should return the previous defined client' do
+    it 'returns the previous defined client' do
       VCR.use_cassette('single_host_with_downtimes', record: :new_episodes) do
-        expect(subject.api_client).to eq client
+        expect(downtime.api_client).to eq client
       end
     end
   end
 
   describe '#to_s' do
-    it 'should return Icinga2 downtime name' do
+    it 'returns Icinga2 downtime name' do
       VCR.use_cassette('single_host_with_downtimes', record: :new_episodes) do
-        expect(subject.to_s).to include('foo.example.net!dockerd|daemon')
+        expect(downtime.to_s).to include('foo.example.net!dockerd|daemon')
       end
     end
   end
 
   describe '#full_name' do
-    it 'should return Icinga2 downtime full_name' do
+    it 'returns Icinga2 downtime full_name' do
       VCR.use_cassette('single_host_with_downtimes', record: :new_episodes) do
-        expect(subject.full_name).to include('foo.example.net!dockerd|daemon')
+        expect(downtime.full_name).to include('foo.example.net!dockerd|daemon')
       end
     end
   end
 
   describe '#cancel' do
-    it 'should cancel Icinga2 downtime' do
+    it 'cancels Icinga2 downtime' do
       VCR.use_cassette('single_host_cancel_downtimes', record: :new_episodes) do
-        expect(subject.cancel).to be_a(Hash)
+        expect(downtime.cancel).to be_a(Hash)
       end
     end
   end
diff --git a/spec/icinga2/api/host_spec.rb b/spec/icinga2/api/host_spec.rb
index 9e64d21..3f6666a 100644
--- a/spec/icinga2/api/host_spec.rb
+++ b/spec/icinga2/api/host_spec.rb
@@ -1,52 +1,53 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Icinga2::API::Host do
 
-  let(:client) { Icinga2::API::Client.new('https://icinga2.example.net:5665', icinga_credentials) }
+  subject(:host) { client.hosts.find('foo.example.net') }
 
-  subject { client.hosts.find('foo.example.net') }
+  let(:client) { Icinga2::API::Client.new('https://icinga2.example.net:5665', icinga_credentials) }
 
   describe '#api_client' do
-    it 'should return the previous defined client' do
+    it 'returns the previous defined client' do
       VCR.use_cassette('single_host') do
-        expect(subject.api_client).to eq client
+        expect(host.api_client).to eq client
       end
     end
   end
 
   describe '#to_s' do
-    it 'should return Icinga2 host name' do
+    it 'returns Icinga2 host name' do
       VCR.use_cassette('single_host') do
-        expect(subject.to_s).to eq 'foo.example.net'
+        expect(host.to_s).to eq 'foo.example.net'
       end
     end
   end
 
   describe '#to_h' do
-    it 'should return host attributes as a hash' do
+    it 'returns host attributes as a hash' do
       VCR.use_cassette('single_host') do
-        expect(subject.to_h).to be_a(Hash)
-        expect(subject.to_h[:name]).to eq 'foo.example.net'
+        expect(host.to_h).to be_a(Hash)
+        expect(host.to_h[:name]).to eq 'foo.example.net'
       end
     end
   end
 
   describe '#name' do
-    it 'should return Icinga2 host name' do
+    it 'returns Icinga2 host name' do
       VCR.use_cassette('single_host') do
-        expect(subject.to_s).to eq 'foo.example.net'
+        expect(host.name).to eq 'foo.example.net'
       end
     end
   end
 
   describe '#services' do
-    it 'should return Icinga2 host services' do
+    it 'returns Icinga2 host services' do
       VCR.use_cassette('single_host_with_services') do
-        expect(subject.services).to be_a(Icinga2::API::Services)
-        expect(subject.services.host).to eq subject
-        expect(subject.services.api_client).to eq subject.api_client
+        expect(host.services).to be_a(Icinga2::API::Services)
+        expect(host.services.host).to eq host
+        expect(host.services.api_client).to eq host.api_client
       end
     end
   end
-
 end
diff --git a/spec/icinga2/api/hosts_spec.rb b/spec/icinga2/api/hosts_spec.rb
index d3e19c0..96aad1a 100644
--- a/spec/icinga2/api/hosts_spec.rb
+++ b/spec/icinga2/api/hosts_spec.rb
@@ -1,23 +1,25 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Icinga2::API::Hosts do
 
-  let(:client) { Icinga2::API::Client.new('https://icinga2.example.net:5665', icinga_credentials) }
+  subject(:all_hosts) { client.hosts }
 
-  subject { client.hosts }
+  let(:client) { Icinga2::API::Client.new('https://icinga2.example.net:5665', icinga_credentials) }
 
   describe '#api_client' do
-    it 'should return the previous defined client' do
-      expect(subject.api_client).to eq client
+    it 'returns the previous defined client' do
+      expect(all_hosts.api_client).to eq client
     end
   end
 
   describe '#all' do
-    it 'should return all Icinga2 hosts' do
+    it 'returns all Icinga2 hosts' do
       VCR.use_cassette('all_hosts') do
         # Store the request result to not trigger it
         # multiple times
-        hosts = subject.all
+        hosts = all_hosts.all
         host1 = hosts.first
         host2 = hosts.last
 
@@ -30,11 +32,11 @@
 
   describe '#find' do
     context 'when Icinga2 host exist' do
-      it 'should return host object' do
+      it 'returns host object' do
         VCR.use_cassette('find_existing_host') do
           # Store the request result to not trigger it
           # multiple times
-          host = subject.find('foo.example.net')
+          host = all_hosts.find('foo.example.net')
 
           expect(host).to be_a(Icinga2::API::Host)
           expect(host.to_s).to eq 'foo.example.net'
@@ -44,11 +46,11 @@
     end
 
     context 'when Icinga2 host dont exist' do
-      it 'should return nil' do
+      it 'returns nil' do
         VCR.use_cassette('find_null_host') do
           # Store the request result to not trigger it
           # multiple times
-          host = subject.find('baz.example.net')
+          host = all_hosts.find('baz.example.net')
           expect(host).to be_nil
         end
       end
diff --git a/spec/icinga2/api/resource_spec.rb b/spec/icinga2/api/resource_spec.rb
index 4cf3183..9465f70 100644
--- a/spec/icinga2/api/resource_spec.rb
+++ b/spec/icinga2/api/resource_spec.rb
@@ -1,55 +1,57 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Icinga2::API::Resource do
 
-  let(:client) { Icinga2::API::Client.new('https://icinga2.example.net:5665', icinga_credentials) }
+  subject(:resource) { described_class.new(api_client: client.api, foo: 'bar', bar: 'foo') }
 
-  subject { described_class.new(api_client: client.api, foo: 'bar', bar: 'foo') }
+  let(:client) { Icinga2::API::Client.new('https://icinga2.example.net:5665', icinga_credentials) }
 
   describe '#to_yaml_properties' do
-    it 'should return the list of attributes to render in the YAML dump' do
-      expect(subject.to_yaml_properties).to eq [:@attributes]
+    it 'returns the list of attributes to render in the YAML dump' do
+      expect(resource.to_yaml_properties).to eq [:@attributes]
     end
   end
 
   describe '#to_hash' do
     context 'when no option is passed' do
-      it 'should return a hash of stored attributes' do
-        expect(subject.to_hash).to eq({ foo: 'bar', bar: 'foo' })
+      it 'returns a hash of stored attributes' do
+        expect(resource.to_hash).to eq({ foo: 'bar', bar: 'foo' })
       end
     end
 
     context 'when except option is passed' do
-      it 'should return a hash of stored attributes' do
-        expect(subject.to_hash(except: ['foo'])).to eq({ bar: 'foo' })
+      it 'returns a hash of stored attributes' do
+        expect(resource.to_hash(except: ['foo'])).to eq({ bar: 'foo' })
       end
     end
 
     context 'when only option is passed' do
-      it 'should return a hash of stored attributes' do
-        expect(subject.to_hash(only: ['foo'])).to eq({ foo: 'bar' })
+      it 'returns a hash of stored attributes' do
+        expect(resource.to_hash(only: ['foo'])).to eq({ foo: 'bar' })
       end
     end
   end
 
   describe '#dynamic_method' do
-    it 'should return stored attributes' do
-      expect(subject.foo).to eq 'bar'
-      expect(subject.bar).to eq 'foo'
+    it 'returns stored attributes' do
+      expect(resource.foo).to eq 'bar'
+      expect(resource.bar).to eq 'foo'
     end
   end
 
   describe '#method_missing' do
     context 'when method exist' do
-      it 'should return the value' do
-        expect(subject.foo).to eq 'bar'
+      it 'returns the value' do
+        expect(resource.foo).to eq 'bar'
       end
     end
 
     context 'when method dont exist' do
-      it 'should call super (and raise error)' do
+      it 'calls super (and raise error)' do
         expect {
-          subject.baz
+          resource.baz
         }.to raise_error(NoMethodError)
       end
     end
@@ -57,14 +59,14 @@
 
   describe '#respond_to_missing?' do
     context 'when method exist' do
-      it 'should return true' do
-        expect(subject.respond_to?(:foo)).to be true
+      it 'returns true' do
+        expect(resource.respond_to?(:foo)).to be true
       end
     end
 
     context 'when method dont exist' do
-      it 'should return false' do
-        expect(subject.respond_to?(:baz)).to be false
+      it 'returns false' do
+        expect(resource.respond_to?(:baz)).to be false
       end
     end
   end
diff --git a/spec/icinga2/api/service_spec.rb b/spec/icinga2/api/service_spec.rb
index 2c3567d..225ecde 100644
--- a/spec/icinga2/api/service_spec.rb
+++ b/spec/icinga2/api/service_spec.rb
@@ -1,49 +1,51 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Icinga2::API::Service do
 
-  let(:client) { Icinga2::API::Client.new('https://icinga2.example.net:5665', icinga_credentials) }
+  subject(:service) { client.hosts.find('foo.example.net').services.find('dockerd|daemon') }
 
-  subject { client.hosts.find('foo.example.net').services.find('dockerd|daemon') }
+  let(:client) { Icinga2::API::Client.new('https://icinga2.example.net:5665', icinga_credentials) }
 
   describe '#api_client' do
-    it 'should return the previous defined client' do
+    it 'returns the previous defined client' do
       VCR.use_cassette('single_host_with_services', record: :new_episodes) do
-        expect(subject.api_client).to eq client
+        expect(service.api_client).to eq client
       end
     end
   end
 
   describe '#to_s' do
-    it 'should return Icinga2 service name' do
+    it 'returns Icinga2 service name' do
       VCR.use_cassette('single_host_with_services', record: :new_episodes) do
-        expect(subject.to_s).to eq 'foo.example.net!dockerd|daemon'
+        expect(service.to_s).to eq 'foo.example.net!dockerd|daemon'
       end
     end
   end
 
   describe '#to_h' do
-    it 'should return service attributes as a hash' do
+    it 'returns service attributes as a hash' do
       VCR.use_cassette('single_host_with_services', record: :new_episodes) do
-        expect(subject.to_h).to be_a(Hash)
-        expect(subject.to_h[:name]).to eq 'dockerd|daemon'
+        expect(service.to_h).to be_a(Hash)
+        expect(service.to_h[:name]).to eq 'dockerd|daemon'
       end
     end
   end
 
   describe '#full_name' do
-    it 'should return Icinga2 service full_name' do
+    it 'returns Icinga2 service full_name' do
       VCR.use_cassette('single_host_with_services', record: :new_episodes) do
-        expect(subject.full_name).to eq 'foo.example.net!dockerd|daemon'
+        expect(service.full_name).to eq 'foo.example.net!dockerd|daemon'
       end
     end
   end
 
   describe '#downtimes' do
     context 'when Icinga2 no downtimes exist' do
-      it 'should return empty array' do
+      it 'returns empty array' do
         VCR.use_cassette('service_without_downtimes') do
-          downtimes = subject.downtimes
+          downtimes = service.downtimes
           expect(downtimes).to be_a(Array)
           expect(downtimes.size).to eq 0
         end
@@ -51,10 +53,10 @@
     end
 
     context 'when Icinga2 downtimes exist' do
-      it 'should return all Icinga2 downtimes for the service' do
+      it 'returns all Icinga2 downtimes for the service' do
         VCR.use_cassette('service_with_downtimes', record: :new_episodes) do
           create_downtime('foo.example.net', 'dockerd|daemon')
-          downtimes = subject.downtimes
+          downtimes = service.downtimes
 
           expect(downtimes.size).to eq 1
           expect(downtimes.first.to_s).to include('foo.example.net!dockerd|daemon')
@@ -62,5 +64,4 @@
       end
     end
   end
-
 end
diff --git a/spec/icinga2/api/services_spec.rb b/spec/icinga2/api/services_spec.rb
index 64d42e9..49b2234 100644
--- a/spec/icinga2/api/services_spec.rb
+++ b/spec/icinga2/api/services_spec.rb
@@ -1,15 +1,17 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Icinga2::API::Services do
 
-  let(:client) { Icinga2::API::Client.new('https://icinga2.example.net:5665', icinga_credentials) }
+  subject(:all_services) { client.hosts.find('foo.example.net').services }
 
-  subject { client.hosts.find('foo.example.net').services }
+  let(:client) { Icinga2::API::Client.new('https://icinga2.example.net:5665', icinga_credentials) }
 
   describe '#all' do
-    it 'should return all Icinga2 services for the host' do
+    it 'returns all Icinga2 services for the host' do
       VCR.use_cassette('single_host_with_services', record: :new_episodes) do
-        services = subject.all
+        services = all_services.all
         expect(services.size).to eq 2
         expect(services.first.to_s).to eq 'foo.example.net!dockerd|daemon'
       end
@@ -18,9 +20,9 @@
 
   describe '#find' do
     context 'when Icinga2 service host exist' do
-      it 'should return service object' do
+      it 'returns service object' do
         VCR.use_cassette('single_host_with_services', record: :new_episodes) do
-          service = subject.find('dockerd|daemon')
+          service = all_services.find('dockerd|daemon')
           expect(service).to be_a(Icinga2::API::Service)
           expect(service.to_s).to eq 'foo.example.net!dockerd|daemon'
         end
@@ -28,9 +30,9 @@
     end
 
     context 'when Icinga2 service host dont exist' do
-      it 'should return nil' do
+      it 'returns nil' do
         VCR.use_cassette('single_host_with_services', record: :new_episodes) do
-          expect(subject.find('foo')).to be_nil
+          expect(all_services.find('foo')).to be_nil
         end
       end
     end
@@ -38,9 +40,9 @@
 
   describe '#downtimes' do
     context 'when Icinga2 no downtimes exist' do
-      it 'should return empty array' do
+      it 'returns empty array' do
         VCR.use_cassette('single_host_without_downtimes') do
-          downtimes = subject.downtimes
+          downtimes = all_services.downtimes
 
           expect(downtimes).to be_a(Array)
           expect(downtimes.size).to eq 0
@@ -49,17 +51,15 @@
     end
 
     context 'when Icinga2 downtimes exist' do
-      it 'should return all Icinga2 services downtimes for the host' do
+      it 'returns all Icinga2 services downtimes for the host' do
         VCR.use_cassette('single_host_with_downtimes', record: :new_episodes) do
           create_downtime('foo.example.net', 'dockerd|daemon')
-          downtimes = subject.downtimes
+          downtimes = all_services.downtimes
 
           expect(downtimes.size).to eq 1
           expect(downtimes.first.to_s).to include('foo.example.net!dockerd|daemon')
         end
       end
     end
-
   end
-
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index d6a1c0f..6bc3872 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'simplecov'
 require 'rspec'
 require 'vcr'
@@ -31,7 +33,7 @@ def icinga_credentials
   { version: 'v1', username: 'root', password: ENV.fetch('ICINGA_API_PASSWORD', 'root'), verify_ssl: false }
 end
 
-def create_downtime(host, service)
+def create_downtime(host, service) # rubocop:disable Metrics/MethodLength
   duration   = 300
   start_time = DateTime.now
   end_time   = start_time + duration