Update change_date field of records for MySQL and PostgreSQL

README.md

@@ -75,6 +75,18 @@ Or a more complex example:
 
 Note that PowerDNS 4.x now uses `pdnsutil` rather than `pdnssec`.
 
+### SOA autoserial with MySQL and PostgreSQL
+
+PowerDNS (>= 3.3) provides a feature called `autoserial` that takes care of managing the serial of `SOA` records.
+
+There are many options available regarding how PowerDNS generates the serial and details can be found looking for the `SOA-EDIT` option in PowerDNS.
+
+One option is to let the PowerDNS backend determine the `SOA` serial using the biggest `change_date` of the records associated with the DNS domain.
+`smart_proxy_dns_powerdns` uses this approach and updates the `change_date` field of changed records, setting them to the current timestamp of the database server, represented as **the number of seconds since EPOCH**.
+
+* when a new record is created, its `change_date` is set accordingly
+* when a record is deleted, the `change_date` of the `SOA` record for the domain is updated
+
 ## Contributing
 
 Fork and send a Pull Request. Thanks!

lib/smart_proxy_dns_powerdns/backend/mysql.rb

@@ -35,15 +35,24 @@ def create_record domain_id, name, type, content
       name = connection.escape(name)
       content = connection.escape(content)
       type = connection.escape(type)
-      connection.query("INSERT INTO records (domain_id, name, ttl, content, type) VALUES (#{domain_id}, '#{name}', #{ttl.to_i}, '#{content}', '#{type}')")
+      connection.query("INSERT INTO records (domain_id, name, ttl, content, type, change_date) VALUES (#{domain_id}, '#{name}', #{ttl.to_i}, '#{content}', '#{type}', UNIX_TIMESTAMP())")
       connection.affected_rows == 1
     end
 
     def delete_record domain_id, name, type
       name = connection.escape(name)
       type = connection.escape(type)
       connection.query("DELETE FROM records WHERE domain_id=#{domain_id} AND name='#{name}' AND type='#{type}'")
-      connection.affected_rows >= 1
+      return false if connection.affected_rows == 0
+
+      connection.query("UPDATE records SET change_date=UNIX_TIMESTAMP() WHERE domain_id=#{domain_id} AND type='SOA'")
+      affected_rows = connection.affected_rows
+      if affected_rows > 1
+        logger.warning("Updated multiple SOA records (host=#{name}, domain_id=#{domain_id}). Check your zone records for duplicate SOA entries.")
+      elsif affected_rows == 0
+        logger.info("No SOA record updated (host=#{name}, domain_id=#{domain_id}). This can be caused by either a missing SOA record for the zone or consecutive updates of the same zone during the same second.")
+      end
+      true
     end
   end
 end

lib/smart_proxy_dns_powerdns/backend/postgresql.rb

@@ -30,13 +30,22 @@ def get_zone name
     end
 
     def create_record domain_id, name, type, content
-      result = connection.exec_params("INSERT INTO records (domain_id, name, ttl, content, type) VALUES ($1::int, $2, $3::int, $4, $5)", [domain_id, name, ttl, content, type])
+      result = connection.exec_params("INSERT INTO records (domain_id, name, ttl, content, type, change_date) VALUES ($1::int, $2, $3::int, $4, $5, extract(epoch from now()))", [domain_id, name, ttl, content, type])
       result.cmdtuples == 1
     end
 
     def delete_record domain_id, name, type
       result = connection.exec_params("DELETE FROM records WHERE domain_id=$1::int AND name=$2 AND type=$3", [domain_id, name, type])
-      result.cmdtuples >= 1
+      return false if result.cmdtuples == 0
+
+      result = connection.exec_params("UPDATE records SET change_date=extract(epoch from now()) WHERE domain_id=$1::int AND type='SOA'", [domain_id])
+      affected_rows = result.cmdtuples
+      if affected_rows > 1
+        logger.warning("Updated multiple SOA records (host=#{name}, domain_id=#{domain_id}). Check your zone records for duplicate SOA entries.")
+      elsif affected_rows == 0
+        logger.info("No SOA record updated (host=#{name}, domain_id=#{domain_id}). This can be caused by either a missing SOA record for the zone or consecutive updates of the same zone during the same second.")
+      end
+      true
     end
   end
 end

test/unit/dns_powerdns_record_mysql_test.rb

@@ -39,19 +39,76 @@ def test_create_record
     @connection.expects(:escape).with('test.example.com').returns('test.example.com')
     @connection.expects(:escape).with('A').returns('A')
     @connection.expects(:escape).with('10.1.1.1').returns('10.1.1.1')
-    @connection.expects(:query).with("INSERT INTO records (domain_id, name, ttl, content, type) VALUES (1, 'test.example.com', 86400, '10.1.1.1', 'A')")
+    @connection.expects(:query).with("INSERT INTO records (domain_id, name, ttl, content, type, change_date) VALUES (1, 'test.example.com', 86400, '10.1.1.1', 'A', UNIX_TIMESTAMP())")
     @connection.expects(:affected_rows).returns(1)
 
     assert @provider.create_record(1, 'test.example.com', 'A', '10.1.1.1')
   end
 
   def test_delete_record
-    @connection.expects(:escape).with('test.example.com').returns('test.example.com')
-    @connection.expects(:escape).with('A').returns('A')
-    @connection.expects(:query).with("DELETE FROM records WHERE domain_id=1 AND name='test.example.com' AND type='A'")
-    @connection.expects(:affected_rows).returns(1)
+    mock_escapes(fqdn, 'A')
+    @connection.expects(:query).with(query_delete)
+    @connection.expects(:query).with(query_update_soa)
+    @connection.expects(:affected_rows).twice.returns(1)
+    assert @provider.delete_record(domain_id, fqdn, 'A')
+  end
+
+  def test_delete_no_record
+    mock_escapes(fqdn, 'A')
+    @connection.expects(:query).with(query_delete)
+    @connection.expects(:affected_rows).returns(0)
+
+    assert_false @provider.delete_record(domain_id, fqdn, 'A')
+  end
+
+  def test_delete_record_no_soa
+    mock_escapes(fqdn, 'A')
+    @connection.expects(:query).with(query_delete)
+    @connection.expects(:query).with(query_update_soa)
+    @connection.expects(:affected_rows).twice.returns(1, 0)
+    logger = mock()
+    logger.expects(:info)
+    @provider.stubs(:logger).returns(logger)
+
+    assert @provider.delete_record(domain_id, fqdn, 'A')
+  end
+
+  def test_delete_record_multiple_soa
+    mock_escapes(fqdn, 'A')
+    @connection.expects(:query).with(query_delete)
+    @connection.expects(:query).with(query_update_soa)
+    @connection.expects(:affected_rows).twice.returns(1, 2)
+    logger = mock()
+    logger.expects(:warning)
+    @provider.stubs(:logger).returns(logger)
+
+    assert @provider.delete_record(domain_id, fqdn, 'A')
+  end
+
+  private
+
+  def mock_escapes(*elts)
+    elts.each { |e| @connection.expects(:escape).with(e).returns(e) }
+  end
+
+  def domain
+    'example.com'
+  end
+
+  def fqdn
+    "test.#{domain}"
+  end
+
+  def domain_id
+    1
+  end
+
+  def query_delete(type='A')
+    "DELETE FROM records WHERE domain_id=#{domain_id} AND name='#{fqdn}' AND type='#{type}'"
+  end
 
-    assert @provider.delete_record(1, 'test.example.com', 'A')
+  def query_update_soa
+    "UPDATE records SET change_date=UNIX_TIMESTAMP() WHERE domain_id=#{domain_id} AND type='SOA'"
   end
 
 end

test/unit/dns_powerdns_record_postgresql_test.rb

@@ -35,33 +35,91 @@ def test_get_zone_without_existing_zone
 
   def test_create_record
     @connection.expects(:exec_params).
-      with("INSERT INTO records (domain_id, name, ttl, content, type) VALUES ($1::int, $2, $3::int, $4, $5)", [1, 'test.example.com', 86400, '10.1.1.1', 'A']).
+      with("INSERT INTO records (domain_id, name, ttl, content, type, change_date) VALUES ($1::int, $2, $3::int, $4, $5, extract(epoch from now()))", [1, 'test.example.com', 86400, '10.1.1.1', 'A']).
       returns(mock(:cmdtuples => 1))
 
     assert_true @provider.create_record(1, 'test.example.com', 'A', '10.1.1.1')
   end
 
   def test_delete_record_no_records
-    @connection.expects(:exec_params).
-      with("DELETE FROM records WHERE domain_id=$1::int AND name=$2 AND type=$3", [1, 'test.example.com', 'A']).
-      returns(mock(:cmdtuples => 0))
-
-    assert_false @provider.delete_record(1, 'test.example.com', 'A')
+    mock_delete_tuples(0)
+    assert_false run_delete_record
   end
 
   def test_delete_record_single_record
-    @connection.expects(:exec_params).
-      with("DELETE FROM records WHERE domain_id=$1::int AND name=$2 AND type=$3", [1, 'test.example.com', 'A']).
-      returns(mock(:cmdtuples => 1))
+    mock_delete_tuples(1)
+    mock_update_soa_tuples(1)
 
-    assert_true @provider.delete_record(1, 'test.example.com', 'A')
+    assert_true run_delete_record
   end
 
   def test_delete_record_multiple_records
+    mock_delete_tuples(2)
+    mock_update_soa_tuples(1)
+
+    assert_true run_delete_record
+  end
+
+  def test_delete_record_no_soa
+    mock_delete_tuples(1)
+    mock_update_soa_tuples(0)
+    logger = mock()
+    logger.expects(:info)
+    @provider.stubs(:logger).returns(logger)
+
+    assert_true run_delete_record
+  end
+
+  def test_delete_record_multiple_soa
+    mock_delete_tuples(1)
+    mock_update_soa_tuples(2)
+    logger = mock()
+    logger.expects(:warning)
+    @provider.stubs(:logger).returns(logger)
+
+    assert_true run_delete_record
+  end
+
+  private
+
+  def mock_delete_tuples(cmdtuples)
     @connection.expects(:exec_params).
-      with("DELETE FROM records WHERE domain_id=$1::int AND name=$2 AND type=$3", [1, 'test.example.com', 'A']).
-      returns(mock(:cmdtuples => 2))
+      with(query_delete, [domain_id, fqdn, record_type]).
+      returns(mock(:cmdtuples => cmdtuples))
+  end
 
-    assert_true @provider.delete_record(1, 'test.example.com', 'A')
+  def mock_update_soa_tuples(cmdtuples)
+    @connection.expects(:exec_params).
+      with(query_update_soa, [domain_id]).
+      returns(mock(:cmdtuples => cmdtuples))
   end
+
+  def run_delete_record
+    @provider.delete_record(domain_id, fqdn, record_type)
+  end
+
+  def domain
+    'example.com'
+  end
+
+  def fqdn
+    "test.#{domain}"
+  end
+
+  def domain_id
+    1
+  end
+
+  def record_type
+    'A'
+  end
+
+  def query_delete
+    "DELETE FROM records WHERE domain_id=$1::int AND name=$2 AND type=$3"
+  end
+
+  def query_update_soa
+    "UPDATE records SET change_date=extract(epoch from now()) WHERE domain_id=$1::int AND type='SOA'"
+  end
+
 end