diff --git a/.rubocop.yml b/.rubocop.yml
new file mode 100644
index 00000000..263d1dc2
--- /dev/null
+++ b/.rubocop.yml
@@ -0,0 +1,20 @@
+# Rubocop (cookstyle) todo:
+
+# Configuration parameters: AllowSafeAssignment.
+Lint/AssignmentInCondition:
+  Exclude:
+    - 'libraries/manipulator.rb'
+
+Lint/ShadowingOuterLocalVariable:
+  Exclude:
+    - 'libraries/entry.rb'
+    - 'libraries/manipulator.rb'
+
+Style/DoubleNegation:
+  Exclude:
+    - 'libraries/manipulator.rb'
+
+# Configuration parameters: MinBodyLength.
+Style/GuardClause:
+  Exclude:
+    - 'libraries/manipulator.rb'
diff --git a/libraries/entry.rb b/libraries/entry.rb
index 33012439..3beab198 100644
--- a/libraries/entry.rb
+++ b/libraries/entry.rb
@@ -51,12 +51,12 @@ def parse(line)
         raise ArgumentError, "/etc/hosts has a line without hostname: #{line}"
       end
 
-      return self.new(
+      new(
         ip_address: entries[0],
         hostname:   entries[1],
         aliases:    entries[2..-1],
         comment:    comment,
-        priority:   priority,
+        priority:   priority
       )
     end
 
@@ -137,7 +137,7 @@ def priority=(new_priority)
   def to_line
     hosts = [hostname, aliases].flatten.join(' ')
 
-    comments = "# #{comment.to_s}".strip
+    comments = "# #{comment}".strip
     comments << " @#{priority}" unless priority.nil? || @calculated_priority
     comments = comments.strip
     comments = nil if comments == '#'
@@ -167,7 +167,7 @@ def calculated_priority
     return 80 if IPAddr.new('127.0.0.0/8').include?(ip_address) # local
     return 60 if ip_address.ipv4? # ipv4
     return 20 if ip_address.ipv6? # ipv6
-    return 00
+    00
   end
 
   # Removes the scopes pieces of the address, because reasons.
diff --git a/libraries/manipulator.rb b/libraries/manipulator.rb
index a51d9b1d..93c89100 100644
--- a/libraries/manipulator.rb
+++ b/libraries/manipulator.rb
@@ -37,8 +37,8 @@ def initialize(node)
     @node = node
 
     # Fail if no hostsfile is found
-    unless ::File.exists?(hostsfile_path)
-      raise RuntimeError, "No hostsfile exists at `#{hostsfile_path}'!"
+    unless ::File.exist?(hostsfile_path)
+      raise "No hostsfile exists at `#{hostsfile_path}'!"
     end
 
     @entries = []
@@ -50,9 +50,7 @@ def initialize(node)
   # @return [Array<IPAddr>]
   #   the list of IP Addresses
   def ip_addresses
-    @entries.collect do |entry|
-      entry.ip_address
-    end.compact || []
+    @entries.collect(&:ip_address).compact || []
   end
 
   # Add a new record to the hostsfile.
@@ -75,7 +73,7 @@ def add(options = {})
       hostname:   options[:hostname],
       aliases:    options[:aliases],
       comment:    options[:comment],
-      priority:   options[:priority],
+      priority:   options[:priority]
     )
 
     @entries << entry
@@ -264,7 +262,7 @@ def collect_and_flatten(contents)
         hostname:   entry.hostname,
         aliases:    entry.aliases,
         comment:    entry.comment,
-        priority:   !entry.calculated_priority? && entry.priority,
+        priority:   !entry.calculated_priority? && entry.priority
       )
     end
   end
diff --git a/providers/entry.rb b/providers/entry.rb
index dde469af..ed0d1b32 100644
--- a/providers/entry.rb
+++ b/providers/entry.rb
@@ -37,7 +37,7 @@ def whyrun_supported?
     aliases:    new_resource.aliases,
     comment:    new_resource.comment,
     priority:   new_resource.priority,
-    unique:     new_resource.unique,
+    unique:     new_resource.unique
   )
 
   if hostsfile.content_changed?
@@ -60,7 +60,7 @@ def whyrun_supported?
         aliases:    new_resource.aliases,
         comment:    new_resource.comment,
         priority:   new_resource.priority,
-        unique:     new_resource.unique,
+        unique:     new_resource.unique
       )
       hostsfile.save
     end
@@ -80,7 +80,7 @@ def whyrun_supported?
     aliases:    new_resource.aliases,
     comment:    new_resource.comment,
     priority:   new_resource.priority,
-    unique:     new_resource.unique,
+    unique:     new_resource.unique
   )
 
   if hostsfile.content_changed?
@@ -101,7 +101,7 @@ def whyrun_supported?
       aliases:    new_resource.aliases,
       comment:    new_resource.comment,
       priority:   new_resource.priority,
-      unique:     new_resource.unique,
+      unique:     new_resource.unique
     )
 
     if hostsfile.content_changed?
diff --git a/spec/unit/entry_spec.rb b/spec/unit/entry_spec.rb
index ab3fed31..16438cef 100644
--- a/spec/unit/entry_spec.rb
+++ b/spec/unit/entry_spec.rb
@@ -19,7 +19,7 @@
       end
 
       it 'parses aliases' do
-        expect(Entry).to receive(:new).with(ip_address: '1.2.3.4', hostname: 'www.example.com', aliases: ['foo', 'bar'], comment: nil, priority: nil)
+        expect(Entry).to receive(:new).with(ip_address: '1.2.3.4', hostname: 'www.example.com', aliases: %w(foo bar), comment: nil, priority: nil)
         Entry.parse('1.2.3.4      www.example.com foo bar')
       end
 
@@ -29,7 +29,7 @@
       end
 
       it 'parses aliases and comments' do
-        expect(Entry).to receive(:new).with(ip_address: '1.2.3.4', hostname: 'www.example.com', aliases: ['foo', 'bar'], comment: 'This is a comment!', priority: nil)
+        expect(Entry).to receive(:new).with(ip_address: '1.2.3.4', hostname: 'www.example.com', aliases: %w(foo bar), comment: 'This is a comment!', priority: nil)
         Entry.parse('1.2.3.4      www.example.com foo bar     # This is a comment!')
       end
 
@@ -46,18 +46,18 @@
   end
 
   describe '.initialize' do
-    subject { Entry.new(ip_address: '2.3.4.5', hostname: 'www.example.com', aliases: ['foo', 'bar'], comment: 'This is a comment!', priority: 100) }
+    subject { Entry.new(ip_address: '2.3.4.5', hostname: 'www.example.com', aliases: %w(foo bar), comment: 'This is a comment!', priority: 100) }
 
     it 'raises an exception if :ip_address is missing' do
-      expect {
+      expect do
         Entry.new(hostname: 'www.example.com')
-      }.to raise_error(ArgumentError)
+      end.to raise_error(ArgumentError)
     end
 
     it 'raises an exception if :hostname is missing' do
-      expect {
+      expect do
         Entry.new(ip_address: '2.3.4.5')
-      }.to raise_error(ArgumentError)
+      end.to raise_error(ArgumentError)
     end
 
     it 'sets the @ip_address instance variable' do
@@ -76,7 +76,7 @@
 
     it 'sets the @aliases instance variable' do
       expect(subject.aliases).to be_a(Array)
-      expect(subject.aliases).to eq(['foo', 'bar'])
+      expect(subject.aliases).to eq(%w(foo bar))
     end
 
     it 'sets the @comment instance variable' do
diff --git a/spec/unit/manipulator_spec.rb b/spec/unit/manipulator_spec.rb
index 29b56813..199eac14 100644
--- a/spec/unit/manipulator_spec.rb
+++ b/spec/unit/manipulator_spec.rb
@@ -7,17 +7,17 @@
 
   let(:lines) do
     [
-      "127.0.0.1  localhost",
-      "::1  localhost6",
-      "1.2.3.4  example.com",
-      "4.5.6.7  foo.example.com"
+      '127.0.0.1  localhost',
+      '::1  localhost6',
+      '1.2.3.4  example.com',
+      '4.5.6.7  foo.example.com'
     ]
   end
 
   let(:entries) do
     [
-      Entry.new(ip_address: '127.0.0.1', hostname: 'localhost',       to_line: '127.0.0.1  localhost',     priority: 10),
-      Entry.new(ip_address: '::1', hostname: 'localhost6',       to_line: '::1  localhost6',     priority: 11),
+      Entry.new(ip_address: '127.0.0.1', hostname: 'localhost', to_line: '127.0.0.1  localhost', priority: 10),
+      Entry.new(ip_address: '::1', hostname: 'localhost6', to_line: '::1  localhost6', priority: 11),
       Entry.new(ip_address: '1.2.3.4',   hostname: 'example.com',     to_line: '1.2.3.4  example.com',     priority: 20),
       Entry.new(ip_address: '4.5.6.7',   hostname: 'foo.example.com', to_line: '4.5.6.7  foo.example.com', priority: 30)
     ]
@@ -77,7 +77,7 @@
     context 'when the entry does not exist' do
       before do
         allow(manipulator).to receive(:find_entry_by_ip_address)
-          .with(any_args())
+          .with(any_args)
           .and_return(nil)
       end
 
@@ -92,7 +92,7 @@
 
       before do
         allow(manipulator).to receive(:find_entry_by_ip_address)
-          .with(any_args())
+          .with(any_args)
           .and_return(entry)
       end
 
@@ -111,7 +111,7 @@
 
       before do
         allow(manipulator).to receive(:find_entry_by_ip_address)
-          .with(any_args())
+          .with(any_args)
           .and_return(entry)
       end
 
@@ -136,7 +136,7 @@
     context 'when the record does not exist' do
       before do
         allow(manipulator).to receive(:find_entry_by_ip_address)
-          .with(any_args())
+          .with(any_args)
           .and_return(nil)
         allow(manipulator).to receive(:add)
       end
@@ -151,7 +151,7 @@
   describe '#remove' do
     context 'when the entry does not exist' do
       before do
-        allow(manipulator).to receive(:find_entry_by_ip_address).with(any_args()).and_return(nil)
+        allow(manipulator).to receive(:find_entry_by_ip_address).with(any_args).and_return(nil)
       end
 
       it 'does nothing' do
@@ -165,7 +165,7 @@
 
       before do
         allow(manipulator).to receive(:find_entry_by_ip_address)
-          .with(any_args())
+          .with(any_args)
           .and_return(entry)
       end
 
@@ -272,7 +272,7 @@
         expect(manipulator.hostsfile_path).to eq('/etc/hosts')
       end
       it 'returns C:\Windows\system32\drivers\etc\hosts on a Windows machine' do
-        windows_attributes = node.merge({ 'platform_family' => 'windows', 'kernel' => { 'os_info' => { 'system_directory' => 'C:\Windows\system32' } } })
+        windows_attributes = node.merge('platform_family' => 'windows', 'kernel' => { 'os_info' => { 'system_directory' => 'C:\Windows\system32' } })
         expect(Manipulator.new(windows_attributes).hostsfile_path).to eq('C:\Windows\system32\drivers\etc\hosts')
       end
     end
@@ -280,7 +280,7 @@
     context 'with a custom hostsfile node attribute' do
       it 'returns the custom path' do
         custom_path = '/custom/path'
-        expect(Manipulator.new(node.merge({'hostsfile' => { 'path' => custom_path } })).hostsfile_path).to eq(custom_path)
+        expect(Manipulator.new(node.merge('hostsfile' => { 'path' => custom_path })).hostsfile_path).to eq(custom_path)
       end
     end
   end
@@ -293,9 +293,9 @@
         entry = Entry.new(ip_address: '7.8.9.10', hostname: 'new.example.com')
         entries << entry
 
-        expect {
+        expect do
           manipulator.remove_existing_hostnames(entry)
-        }.to_not change(manipulator, :entries)
+        end.to_not change(manipulator, :entries)
       end
     end
 
diff --git a/test/fixtures/cookbooks/fake/recipes/options.rb b/test/fixtures/cookbooks/fake/recipes/options.rb
index acee25a3..a6dbb178 100644
--- a/test/fixtures/cookbooks/fake/recipes/options.rb
+++ b/test/fixtures/cookbooks/fake/recipes/options.rb
@@ -1,6 +1,6 @@
 hostsfile_entry '2.3.4.5' do
   hostname    'www.example.com'
-  aliases     ['foo', 'bar']
+  aliases     %w(foo bar)
   comment     'This is a comment!'
   priority    100
 end