[lib] add valid:duplicate-values: check for duplicate MAC, IP, IPv6 in generated data

lib/refrepo/valid/duplicate_values.rb

+require 'refrepo/data_loader'
+def check_duplicate_values(_options)
+
+  netifs = []
+  refapi = load_data_hierarchy
+  refapi['sites'].each_pair do |site_uid, site|
+    site['clusters'].each_pair do |cluster_uid, cluster|
+      cluster['nodes'].to_h.each do |node_uid, node|
+        node['network_adapters'].each do |na|
+          netifs << { :site => site_uid,
+                      :cluster => cluster_uid,
+                      :node => node_uid,
+                      :iface => na['name'],
+                      :ip => na['ip'],
+                      :ip6 => na['ip6'],
+                      :mac => na['mac'].downcase,
+                      :mounted => na['mounted'],
+                      :mountable => na['mountable']
+          }
+        end
+      end
+    end
+  end
+
+  ret = true
+
+  dupe_macs = netifs.group_by { |e| e[:mac] }.to_a.select { |e| e[1].length > 1 }
+  if not dupe_macs.empty?
+    ret = false
+    dupe_macs.each do |e|
+      puts "ERROR: MAC #{e[0]} is used by several nodes:"
+      puts e[1].map { |n| n.to_s }.join("\n")
+    end
+  end
+
+  dupe_ips = netifs.select { |e| e[:ip] }.group_by { |e| e[:ip] }.to_a.select { |e| e[1].length > 1 }
+  if not dupe_ips.empty?
+    ret = false
+    dupe_ips.each do |e|
+      puts "ERROR: IP #{e[0]} is used by several nodes:"
+      puts e[1].map { |n| n.to_s }.join("\n")
+    end
+  end
+
+  dupe_ip6s = netifs.select { |e| e[:ip6] }.group_by { |e| e[:ip6] }.to_a.select { |e| e[1].length > 1 }
+  if not dupe_ips.empty?
+    ret = false
+    dupe_ip6s.each do |e|
+      puts "ERROR: IPv6 #{e[0]} is used by several nodes:"
+      puts e[1].map { |n| n.to_s }.join("\n")
+    end
+  end
+
+  return ret
+end