Add validate_domain_name function

README.md

@@ -1958,6 +1958,32 @@ validate_cmd($haproxycontent, '/usr/sbin/haproxy -f % -c', 'Haproxy failed to va
 
 *Type*: statement.
 
+#### `validate_domain_name`
+
+**Deprecated. Will be removed in a future version of stdlib. See [`validate_legacy`](#validate_legacy).**
+
+Validate that all values passed are syntactically correct domain names. Aborts catalog compilation if any value fails this check.
+
+The following values pass:
+
+~~~
+$my_domain_name = 'server.domain.tld'
+validate_domain_name($my_domain_name)
+validate_domain_name('domain.tld', 'puppet.com', $my_domain_name)
+~~~
+
+The following values fail, causing compilation to abort:
+
+~~~
+validate_domain_name(1)
+validate_domain_name(true)
+validate_domain_name('invalid domain')
+validate_domain_name('-foo.example.com')
+validate_domain_name('www.example.2com')
+~~~
+
+*Type*: statement.
+
 #### `validate_hash`
 
 **Deprecated. Will be removed in a future version of stdlib. See [`validate_legacy`](#validate_legacy).**

lib/puppet/parser/functions/validate_domain_name.rb

@@ -0,0 +1,39 @@
+module Puppet::Parser::Functions
+  newfunction(:validate_domain_name, :doc => <<-ENDHEREDOC
+    Validate that all values passed are syntactically correct domain names.
+    Fail compilation if any value fails this check.
+
+    The following values will pass:
+
+        $my_domain_name = 'server.domain.tld'
+        validate_domain_name($my_domain_name)
+        validate_domain_name('domain.tld', 'puppet.com', $my_domain_name)
+
+    The following values will fail, causing compilation to abort:
+
+        validate_domain_name(1)
+        validate_domain_name(true)
+        validate_domain_name('invalid domain')
+        validate_domain_name('-foo.example.com')
+        validate_domain_name('www.example.2com')
+
+    ENDHEREDOC
+  ) do |args|
+
+    rescuable_exceptions = [ArgumentError]
+
+    if args.empty?
+      raise Puppet::ParseError, "validate_domain_name(): wrong number of arguments (#{args.length}; must be > 0)"
+    end
+
+    args.each do |arg|
+      raise Puppet::ParseError, "#{arg.inspect} is not a string." unless arg.is_a?(String)
+
+      begin
+        raise Puppet::ParseError, "#{arg.inspect} is not a syntactically correct domain name" unless function_is_domain_name([arg])
+      rescue *rescuable_exceptions
+        raise Puppet::ParseError, "#{arg.inspect} is not a syntactically correct domain name"
+      end
+    end
+  end
+end

spec/functions/validate_domain_name_spec.rb

@@ -0,0 +1,35 @@
+require 'spec_helper'
+
+describe 'validate_domain_name' do
+  describe 'signature validation' do
+    it { is_expected.not_to eq(nil) }
+    it { is_expected.to run.with_params().and_raise_error(Puppet::ParseError, /wrong number of arguments/i) }
+  end
+
+  describe 'valid inputs' do
+    it { is_expected.to run.with_params('com', 'com.') }
+    it { is_expected.to run.with_params('x.com', 'x.com.') }
+    it { is_expected.to run.with_params('foo.example.com', 'foo.example.com.') }
+    it { is_expected.to run.with_params('2foo.example.com', '2foo.example.com.') }
+    it { is_expected.to run.with_params('www.2foo.example.com', 'www.2foo.example.com.') }
+    it { is_expected.to run.with_params('domain.tld', 'puppet.com') }
+  end
+
+  describe 'invalid inputs' do
+    it { is_expected.to run.with_params([]).and_raise_error(Puppet::ParseError, /is not a string/) }
+    it { is_expected.to run.with_params({}).and_raise_error(Puppet::ParseError, /is not a string/) }
+    it { is_expected.to run.with_params(1).and_raise_error(Puppet::ParseError, /is not a string/) }
+    it { is_expected.to run.with_params(true).and_raise_error(Puppet::ParseError, /is not a string/) }
+
+    it { is_expected.to run.with_params('foo.example.com', []).and_raise_error(Puppet::ParseError, /is not a string/) }
+    it { is_expected.to run.with_params('foo.example.com', {}).and_raise_error(Puppet::ParseError, /is not a string/) }
+    it { is_expected.to run.with_params('foo.example.com', 1).and_raise_error(Puppet::ParseError, /is not a string/) }
+    it { is_expected.to run.with_params('foo.example.com', true).and_raise_error(Puppet::ParseError, /is not a string/) }
+
+    it { is_expected.to run.with_params('').and_raise_error(Puppet::ParseError, /is not a syntactically correct domain name/) }
+    it { is_expected.to run.with_params('invalid domain').and_raise_error(Puppet::ParseError, /is not a syntactically correct domain name/) }
+    it { is_expected.to run.with_params('-foo.example.com').and_raise_error(Puppet::ParseError, /is not a syntactically correct domain name/) }
+    it { is_expected.to run.with_params('www.example.2com').and_raise_error(Puppet::ParseError, /is not a syntactically correct domain name/) }
+    it { is_expected.to run.with_params('192.168.1.1').and_raise_error(Puppet::ParseError, /is not a syntactically correct domain name/) }
+  end
+end