added nameservier validator during creating or updating nameservers

app/models/domain.rb

@@ -49,7 +49,6 @@ class Domain < ApplicationRecord
     statuses.include? DomainStatus::SERVER_REGISTRANT_CHANGE_PROHIBITED
   end
 
-
   # NB! contacts, admin_contacts, tech_contacts are empty for a new record
   has_many :domain_contacts, dependent: :destroy
   has_many :contacts, through: :domain_contacts, source: :contact

app/models/nameserver.rb

@@ -31,6 +31,7 @@ class Nameserver < ApplicationRecord
   before_validation :normalize_attributes
   before_validation :check_puny_symbols
   before_validation :check_label_length
+  before_validation :check_presence_of_dnssec_keys 
 
   delegate :name, to: :domain, prefix: true
 
@@ -55,6 +56,36 @@ class Nameserver < ApplicationRecord
     }
   end
 
+  def check_presence_of_dnssec_keys
+    r = NameserverValidator.run(domain_name: domain, nameserver: self)
+    return if r[:result]
+
+    text = parse_result(r, self)
+    add_epp_error(2302, self, self.hostname, text)
+  end
+
+  def parse_result(result, nameserver)
+    text = ''
+    case result[:reason]
+    when 'answer'
+      text = "DNS Server **#{nameserver.hostname}** not responding"
+    when 'serial'
+      text = "Serial number for nameserver hostname **#{nameserver.hostname}** of #{nameserver.domain.name} doesn't present in zone. SOA validation failed."
+    when 'cname'
+      text = "Warning: SOA record expected but CNAME found instead. This setup can lead to unexpected errors when using the domain: hostname - **#{nameserver.hostname}** of #{nameserver.domain.name}"
+    when 'not found'
+      text = "Seems nameserver hostname **#{nameserver.hostname}** doesn't exist"
+    when 'exception'
+      text = "Something went wrong, exception reason: **#{result[:error_info]}**"
+    when 'domain'
+      text = "#{domain.name} zone is not in nameserver**#{nameserver.hostname}**"
+    when 'glup record'
+      text = "Hostname #{nameserver.hostname} didn't resovle by glue record to #{domain.name}"
+    end
+
+    text
+  end
+
   def failed_validation?
     return false if validation_counter.nil?
 

app/services/nameserver_validator.rb

@@ -11,11 +11,9 @@ module NameserverValidator
     result_response = validate(domain_name: domain_name, hostname: nameserver.hostname)
 
     unless result_response[:result] && result_response[:reason] == :exception
-      if result_response[:error_info].to_s.include? "Nameserver invalid!"
+      if result_response[:error_info].to_s.include? 'Nameserver invalid!'
         if nameserver.ipv4.present?
           result_response = validate(domain_name: domain_name, hostname: nameserver.ipv4)
-        # elsif nameserver.ipv6.present?
-        #   result_response = validate(domain_name: domain_name, hostname: nameserver.ipv6)
         end
 
         return { result: false, reason: 'glup record' } unless result_response[:result]