diff --git a/src/cli/onevm b/src/cli/onevm
index 3cee2b84e6..ff2fbeb1b3 100755
--- a/src/cli/onevm
+++ b/src/cli/onevm
@@ -1670,14 +1670,16 @@ CommandParser::CmdParser.new(ARGV) do
             i_end_p   = Integer(i_range[1].split('/')[0])
 
             if args[1].nil?
-                [*e_start_p..e_end_p].zip([*i_start_p..i_end_p]) do |p1, p2|
+                start_r = Array(e_start_p..e_end_p)
+                end_r   = Array(i_start_p..i_end_p)
+
+                start_r.zip(end_r) do |p1, p2|
                     puts "#{ip}@#{p1} -> #{p2}"
                 end
             else
                 puts "#{ip}@#{e_start_p + Integer(args[1]) - 1} -> #{args[1]}"
             end
         end
-
     end
 
     # Deprecated commands
diff --git a/src/flow/lib/models/service.rb b/src/flow/lib/models/service.rb
index 2ade5b0829..6a2c6c7e20 100644
--- a/src/flow/lib/models/service.rb
+++ b/src/flow/lib/models/service.rb
@@ -140,12 +140,14 @@ module OpenNebula
         # Return true if the service can be undeployed
         # @return true if the service can be undeployed, false otherwise
         def can_undeploy?
+            # rubocop:disable Style/IfWithBooleanLiteralBranches
             if (transient_state? && state != Service::STATE['UNDEPLOYING']) ||
                 state == Service::STATE['DONE'] || failed_state?
                 false
             else
                 true
             end
+            # rubocop:enable Style/IfWithBooleanLiteralBranches
         end
 
         # Return true if the service can be updated
diff --git a/src/flow/lib/strategy.rb b/src/flow/lib/strategy.rb
index 266c84f574..7af826d4b4 100644
--- a/src/flow/lib/strategy.rb
+++ b/src/flow/lib/strategy.rb
@@ -34,7 +34,7 @@ module Strategy
 
         # Ruby 1.8 compatibility
         if result.instance_of?(Array)
-            result = Hash[result]
+            result = result.to_h
         end
 
         result
@@ -52,7 +52,7 @@ module Strategy
 
         # Ruby 1.8 compatibility
         if result.instance_of?(Array)
-            result = Hash[result]
+            result = result.to_h
         end
 
         result
diff --git a/src/flow/lib/strategy/straight.rb b/src/flow/lib/strategy/straight.rb
index 5371c15fdd..3d52e935bb 100644
--- a/src/flow/lib/strategy/straight.rb
+++ b/src/flow/lib/strategy/straight.rb
@@ -77,7 +77,7 @@ module Straight
 
         # Ruby 1.8 compatibility
         if running_roles.instance_of?(Array)
-            running_roles = Hash[running_roles]
+            running_roles = running_roles.to_h
         end
 
         result = roles.select do |_name, role|
@@ -99,7 +99,7 @@ module Straight
 
         # Ruby 1.8 compatibility
         if result.instance_of?(Array)
-            result = Hash[result]
+            result = result.to_h
         end
 
         result
@@ -134,7 +134,7 @@ module Straight
 
         # Ruby 1.8 compatibility
         if result.instance_of?(Array)
-            result = Hash[result]
+            result = result.to_h
         end
 
         result
diff --git a/src/ipamm_mad/remotes/packet/register_address_range b/src/ipamm_mad/remotes/packet/register_address_range
index 18416eaa6b..0affde86da 100755
--- a/src/ipamm_mad/remotes/packet/register_address_range
+++ b/src/ipamm_mad/remotes/packet/register_address_range
@@ -112,8 +112,9 @@ require 'digest'
 
 IP_TYPE = %w[public_ipv4 global_ipv4]
 
-DEFAULT_PRIVATE_CIDR = "172.16.0.0/12"
+DEFAULT_PRIVATE_CIDR = '172.16.0.0/12'
 
+# IP Address class
 class IPAddr
 
     # Add ^ operator to the IPAddr class
@@ -131,7 +132,7 @@ class IPAddr
             n = IN6MASK ^ @mask_addr
             i = 128
         else
-            raise AddressFamilyError, "unsupported address family"
+            raise AddressFamilyError, 'unsupported address family'
         end
         while n>0
             n >>= 1
@@ -139,6 +140,7 @@ class IPAddr
         end
         i
     end
+
 end
 
 begin
@@ -206,7 +208,7 @@ begin
 
     packet.create_ip(ip)
 
-    ipmd5 = Digest::MD5.hexdigest("#{ip.address}").to_i(16) & mask
+    ipmd5 = Digest::MD5.hexdigest(ip.address.to_s).to_i(16) & mask
     eip   = IPAddr.new(ipmd5, Socket::AF_INET)
 
     ipvm = (eip & mask) | cidr
diff --git a/src/oca/ruby/opennebula/wait_ext.rb b/src/oca/ruby/opennebula/wait_ext.rb
index b9fa6b210c..34d0e6ad0b 100644
--- a/src/oca/ruby/opennebula/wait_ext.rb
+++ b/src/oca/ruby/opennebula/wait_ext.rb
@@ -14,107 +14,118 @@
 # limitations under the License.                                             #
 #--------------------------------------------------------------------------- #
 
-
 require 'opennebula/host'
 require 'opennebula/image'
 require 'opennebula/virtual_machine'
 
-module OpenNebula::WaitExtEvent
-    def wait_event(ctx, event, timeout)
-        subscriber = ctx.socket(ZMQ::SUB)
+module OpenNebula
 
-        # Create subscriber
-        key        = ''
-        content    = ''
+    # Module to wait OpenNebula objects events using ZMQ
+    module WaitExtEvent
 
-        subscriber.setsockopt(ZMQ::RCVTIMEO, timeout * 1000)
-        subscriber.setsockopt(ZMQ::SUBSCRIBE, event)
-        subscriber.connect(@client.one_zmq)
+        def wait_event(ctx, event, timeout)
+            subscriber = ctx.socket(ZMQ::SUB)
 
-        rc = subscriber.recv_string(key)
-        rc = subscriber.recv_string(content) if rc != -1
+            # Create subscriber
+            key        = ''
+            content    = ''
 
-        return if ZMQ::Util.errno == ZMQ::EAGAIN || rc == -1
+            subscriber.setsockopt(ZMQ::RCVTIMEO, timeout * 1000)
+            subscriber.setsockopt(ZMQ::SUBSCRIBE, event)
+            subscriber.connect(@client.one_zmq)
 
-        content
-    ensure
-        subscriber.setsockopt(ZMQ::UNSUBSCRIBE, event)
-        subscriber.close
-    end
+            rc = subscriber.recv_string(key)
+            rc = subscriber.recv_string(content) if rc != -1
 
-    def wait2(sstr1, sstr2, timeout = 60, cycles = -1)
-        wfun = OpenNebula::WaitExt::WAIT[self.class]
+            return if ZMQ::Util.errno == ZMQ::EAGAIN || rc == -1
 
-        # Start with a timeout of 2 seconds, to wait until the first
-        # info.
-        #
-        # The timeout is increased later, to avoid multiple info calls.
-        c_timeout = 2
-        recvs     = 0
-        in_state  = false
-
-        # Subscribe with timeout seconds
-        #
-        # Subscribe string:
-        #
-        #   EVENT STATE element_name/state_str//self.ID
-        #
-        #   - element_name: is the element name to find in the message
-        #   - self.ID: returns element ID to find in the message
-        ctx = ZMQ::Context.new(1)
-
-        until in_state || (cycles != -1 && recvs >= cycles)
-            content = wait_event(ctx,
-                                 wfun[:event].call(self, sstr1, sstr2),
-                                 c_timeout)
-
-            if content && !content.empty?
-                in_state = wfun[:in_state_e].call(sstr1, sstr2, content)
-
-                break if in_state
-            end
-
-            c_timeout *= 10
-            c_timeout  = timeout if c_timeout > timeout
-
-            rco = info
-
-            return false if OpenNebula.is_error?(rco)
-
-            in_state = wfun[:in_state].call(self, sstr1, sstr2)
-
-            recvs += 1
+            content
+        ensure
+            subscriber.setsockopt(ZMQ::UNSUBSCRIBE, event)
+            subscriber.close
+        end
+
+        def wait2(sstr1, sstr2, timeout = 60, cycles = -1)
+            wfun = OpenNebula::WaitExt::WAIT[self.class]
+
+            # Start with a timeout of 2 seconds, to wait until the first
+            # info.
+            #
+            # The timeout is increased later, to avoid multiple info calls.
+            c_timeout = 2
+            recvs     = 0
+            in_state  = false
+
+            # Subscribe with timeout seconds
+            #
+            # Subscribe string:
+            #
+            #   EVENT STATE element_name/state_str//self.ID
+            #
+            #   - element_name: is the element name to find in the message
+            #   - self.ID: returns element ID to find in the message
+            ctx = ZMQ::Context.new(1)
+
+            until in_state || (cycles != -1 && recvs >= cycles)
+                content = wait_event(ctx,
+                                     wfun[:event].call(self, sstr1, sstr2),
+                                     c_timeout)
+
+                if content && !content.empty?
+                    in_state = wfun[:in_state_e].call(sstr1, sstr2, content)
+
+                    break if in_state
+                end
+
+                c_timeout *= 10
+                c_timeout  = timeout if c_timeout > timeout
+
+                rco = info
+
+                return false if OpenNebula.is_error?(rco)
+
+                in_state = wfun[:in_state].call(self, sstr1, sstr2)
+
+                recvs += 1
+            end
+
+            in_state
         end
 
-        in_state
     end
 
 end
 
-module OpenNebula::WaitExtPolling
-    def wait2(sstr1, sstr2, timeout = 60, cycles = -1)
-        wfun = OpenNebula::WaitExt::WAIT[self.class]
+module OpenNebula
 
-        stime    = 5
-        recvs    = 0
-        cycles   = timeout / stime
-        in_state = false
+    # Module to wait OpenNebula objects events using polling
+    module WaitExtPolling
 
-        loop do
-            rco = info
+        def wait2(sstr1, sstr2, timeout = 60, cycles = -1)
+            wfun = OpenNebula::WaitExt::WAIT[self.class]
 
-            return false if OpenNebula.is_error?(rco)
+            stime    = 5
+            recvs    = 0
+            cycles   = timeout / stime if cycles == -1
+            in_state = false
 
-            in_state = wfun[:in_state].call(self, sstr1, sstr2)
+            loop do
+                rco = info
 
-            recvs += 1
+                return false if OpenNebula.is_error?(rco)
 
-            break if in_state || recvs >= cycles
+                in_state = wfun[:in_state].call(self, sstr1, sstr2)
 
-            sleep stime
+                recvs += 1
+
+                break if in_state || recvs >= cycles
+
+                sleep stime
+            end
+
+            in_state
         end
 
-        in_state
     end
 
 end
@@ -124,6 +135,7 @@ end
 #
 # rubocop:disable Style/ClassAndModuleChildren
 module OpenNebula::WaitExt
+
     # Wait classes and the name published in ZMQ/STATE
     WAIT = {
         OpenNebula::Host  => {
@@ -176,7 +188,7 @@ module OpenNebula::WaitExt
             },
 
             :in_state => lambda {|o, s1, s2|
-              obj_s1 = Integer(o['STATE'])
+                obj_s1 = Integer(o['STATE'])
                 inx_s1 = OpenNebula::VirtualMachine::VM_STATE.index(s1)
 
                 obj_s2 = Integer(o['LCM_STATE'])
@@ -203,13 +215,15 @@ module OpenNebula::WaitExt
         wait?(obj)
 
         class << obj
-          begin
-            require 'ffi-rzmq'
 
-            include OpenNebula::WaitExtEvent
-          rescue LoadError
-            include OpenNebula::WaitExtPolling
-          end
+            begin
+                require 'ffi-rzmq'
+
+                include OpenNebula::WaitExtEvent
+            rescue LoadError
+                include OpenNebula::WaitExtPolling
+            end
+
         end
 
         super
diff --git a/src/vnm_mad/remotes/elastic/packet_vnm.rb b/src/vnm_mad/remotes/elastic/packet_vnm.rb
index d20d083c23..e0032743ce 100644
--- a/src/vnm_mad/remotes/elastic/packet_vnm.rb
+++ b/src/vnm_mad/remotes/elastic/packet_vnm.rb
@@ -68,7 +68,6 @@ class PacketProvider
         0
     rescue Packet::Error => e
         # potential VM poweroff(itself) + resume
-
         if e.message == '{"errors"=>["Address has already been taken"]}'
             return 0
         end
diff --git a/src/vnm_mad/remotes/elastic/post b/src/vnm_mad/remotes/elastic/post
index 58bf13fdbc..d891410ba2 100755
--- a/src/vnm_mad/remotes/elastic/post
+++ b/src/vnm_mad/remotes/elastic/post
@@ -70,7 +70,7 @@ begin
     begin
         rc = SSHCommand.run(remote_post, hostname, nil, template64)
 
-        raise StandardError.new rc.stderr unless rc.code == 0
+        raise StandardError, rc.stderr unless rc.code == 0
 
         drv.run_hooks(ARGV, template64) if drv.activate == 0
     rescue StandardError => e
diff --git a/src/vnm_mad/remotes/elastic/remote_clean b/src/vnm_mad/remotes/elastic/remote_clean
index a746ecf3f2..75ff203d32 100755
--- a/src/vnm_mad/remotes/elastic/remote_clean
+++ b/src/vnm_mad/remotes/elastic/remote_clean
@@ -16,8 +16,8 @@
 # limitations under the License.                                             #
 #--------------------------------------------------------------------------- #
 
-$: << File.dirname(__FILE__)
-$: << File.join(File.dirname(__FILE__), "..")
+$LOAD_PATH << File.dirname(__FILE__)
+$LOAD_PATH << File.join(File.dirname(__FILE__), '..')
 
 require 'vnmmad'
 
@@ -31,7 +31,7 @@ begin
                                                     deploy_id,
                                                     false)
     filter_driver.deactivate
-rescue Exception => e
+rescue StandardError => e
     OpenNebula.log_error(e.message)
     OpenNebula.log_error(e.backtrace)
     exit 1
diff --git a/src/vnm_mad/remotes/elastic/remote_post b/src/vnm_mad/remotes/elastic/remote_post
index 0e230aa6e8..66917b5dba 100755
--- a/src/vnm_mad/remotes/elastic/remote_post
+++ b/src/vnm_mad/remotes/elastic/remote_post
@@ -16,8 +16,8 @@
 # limitations under the License.                                             #
 #--------------------------------------------------------------------------- #
 
-$: << File.dirname(__FILE__)
-$: << File.join(File.dirname(__FILE__), "..")
+$LOAD_PATH << File.dirname(__FILE__)
+$LOAD_PATH << File.join(File.dirname(__FILE__), '..')
 
 require 'vnmmad'
 
@@ -31,7 +31,7 @@ begin
                                                     deploy_id,
                                                     false)
     filter_driver.activate
-rescue Exception => e
+rescue StandardError => e
     OpenNebula.log_error(e.message)
     OpenNebula.log_error(e.backtrace)
     exit 1
diff --git a/src/vnm_mad/remotes/elastic/update_sg b/src/vnm_mad/remotes/elastic/update_sg
index 96b77ccc57..3f81f0c93b 100755
--- a/src/vnm_mad/remotes/elastic/update_sg
+++ b/src/vnm_mad/remotes/elastic/update_sg
@@ -16,8 +16,8 @@
 # limitations under the License.                                             #
 #--------------------------------------------------------------------------- #
 
-$: << File.dirname(__FILE__)
-$: << File.join(File.dirname(__FILE__), "..")
+$LOAD_PATH << File.dirname(__FILE__)
+$LOAD_PATH << File.join(File.dirname(__FILE__), '..')
 
 require 'vnmmad'
 
@@ -31,7 +31,7 @@ begin
                                                     deploy_id,
                                                     false)
     filter_driver.activate(true)
-rescue Exception => e
+rescue StandardError => e
     OpenNebula.log_error(e.message)
     OpenNebula.log_error(e.backtrace)
     exit 1
diff --git a/src/vnm_mad/remotes/nodeport/clean b/src/vnm_mad/remotes/nodeport/clean
index d731b6bbcb..70af7d8988 100755
--- a/src/vnm_mad/remotes/nodeport/clean
+++ b/src/vnm_mad/remotes/nodeport/clean
@@ -34,7 +34,7 @@ begin
                                                     deploy_id,
                                                     false)
     filter_driver.deactivate
-rescue Exception => e
+rescue StandardError => e
     OpenNebula.log_error(e.message)
     OpenNebula.log_error(e.backtrace)
     exit 1
diff --git a/src/vnm_mad/remotes/nodeport/post b/src/vnm_mad/remotes/nodeport/post
index fb122ffbd8..9ec9060d1c 100755
--- a/src/vnm_mad/remotes/nodeport/post
+++ b/src/vnm_mad/remotes/nodeport/post
@@ -35,7 +35,7 @@ begin
     drv.deactivate
 
     filter_driver.activate(true) if drv.activate == 0
-rescue Exception => e
+rescue StandardError => e
     OpenNebula.log_error(e.message)
     OpenNebula.log_error(e.backtrace)
     exit 1
diff --git a/src/vnm_mad/remotes/nodeport/update_sg b/src/vnm_mad/remotes/nodeport/update_sg
index bd411872ed..6083f78074 100755
--- a/src/vnm_mad/remotes/nodeport/update_sg
+++ b/src/vnm_mad/remotes/nodeport/update_sg
@@ -16,8 +16,8 @@
 # limitations under the License.                                             #
 #--------------------------------------------------------------------------- #
 
-$: << File.dirname(__FILE__)
-$: << File.join(File.dirname(__FILE__), "..")
+$LOAD_PATH << File.dirname(__FILE__)
+$LOAD_PATH << File.join(File.dirname(__FILE__), '..')
 
 require 'vnmmad'
 
@@ -31,7 +31,7 @@ begin
                                                     deploy_id,
                                                     false)
     filter_driver.activate(true)
-rescue Exception => e
+rescue StandardError => e
     OpenNebula.log_error(e.message)
     OpenNebula.log_error(e.backtrace)
     exit 1