Merge pull request #1343 from puppetlabs/fqdn_rand_string

Rewrite fqdn_rand_string() as a Puppet 4.x function

Author: binford2k

lib/puppet/functions/fqdn_rand_string.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+# @summary
+#   Generates a random alphanumeric string. Combining the `$fqdn` fact and an
+#   optional seed for repeatable randomness.
+#
+# Optionally, you can specify a character set for the function (defaults to alphanumeric).
+Puppet::Functions.create_function(:fqdn_rand_string) do
+  # @param length The length of the resulting string.
+  # @param charset The character set to use.
+  # @param The seed for repeatable randomness.
+  #
+  # @return [String]
+  #
+  # @example Example Usage:
+  #   fqdn_rand_string(10)
+  #   fqdn_rand_string(10, 'ABCDEF!@$%^')
+  #   fqdn_rand_string(10, '', 'custom seed')
+  dispatch :fqdn_rand_string do
+    param 'Integer[1]', :length
+    optional_param 'String', :charset
+    optional_repeated_param 'Any', :seed
+  end
+
+  def fqdn_rand_string(length, charset = '', *seed)
+    charset = charset.chars.to_a
+
+    charset = (0..9).map { |i| i.to_s } + ('A'..'Z').to_a + ('a'..'z').to_a if charset.empty?
+
+    rand_string = ''
+    length.times do |current|
+      rand_string += charset[call_function('fqdn_rand', charset.size, (seed + [current + 1]).join(':'))]
+    end
+
+    rand_string
+  end
+end

lib/puppet/parser/functions/fqdn_rand_string.rb

@@ -6,68 +6,50 @@
   let(:default_charset) { %r{\A[a-zA-Z0-9]{100}\z} }
 
   it { is_expected.not_to eq(nil) }
-  it { is_expected.to run.with_params.and_raise_error(ArgumentError, %r{wrong number of arguments}i) }
-  it { is_expected.to run.with_params(0).and_raise_error(ArgumentError, %r{first argument must be a positive integer}) }
-  it { is_expected.to run.with_params(1.5).and_raise_error(ArgumentError, %r{first argument must be a positive integer}) }
-  it { is_expected.to run.with_params(-10).and_raise_error(ArgumentError, %r{first argument must be a positive integer}) }
-  it { is_expected.to run.with_params('-10').and_raise_error(ArgumentError, %r{first argument must be a positive integer}) }
-  it { is_expected.to run.with_params('string').and_raise_error(ArgumentError, %r{first argument must be a positive integer}) }
-  it { is_expected.to run.with_params([]).and_raise_error(ArgumentError, %r{first argument must be a positive integer}) }
-  it { is_expected.to run.with_params({}).and_raise_error(ArgumentError, %r{first argument must be a positive integer}) }
-  it { is_expected.to run.with_params(1, 1).and_raise_error(ArgumentError, %r{second argument must be undef or a string}) }
-  it { is_expected.to run.with_params(1, []).and_raise_error(ArgumentError, %r{second argument must be undef or a string}) }
-  it { is_expected.to run.with_params(1, {}).and_raise_error(ArgumentError, %r{second argument must be undef or a string}) }
+  it { is_expected.to run.with_params.and_raise_error(ArgumentError, %r{expects at least 1 argument, got none}i) }
+  it { is_expected.to run.with_params(0).and_raise_error(ArgumentError, %r{parameter 'length' expects an Integer\[1\] value, got Integer\[0, 0\]}) }
+  it { is_expected.to run.with_params(1.5).and_raise_error(ArgumentError, %r{parameter 'length' expects an Integer\ value, got Float}) }
+  it { is_expected.to run.with_params(-10).and_raise_error(ArgumentError, %r{parameter 'length' expects an Integer\[1\] value, got Integer\[-10, -10\]}) }
+  it { is_expected.to run.with_params('-10').and_raise_error(ArgumentError, %r{parameter 'length' expects an Integer\ value, got String}) }
+  it { is_expected.to run.with_params('string').and_raise_error(ArgumentError, %r{parameter 'length' expects an Integer\ value, got String}) }
+  it { is_expected.to run.with_params([]).and_raise_error(ArgumentError, %r{parameter 'length' expects an Integer value, got Array}) }
+  it { is_expected.to run.with_params({}).and_raise_error(ArgumentError, %r{parameter 'length' expects an Integer value, got Hash}) }
+  it { is_expected.to run.with_params(1, 1).and_raise_error(ArgumentError, %r{parameter 'charset' expects a String value, got Integer}) }
+  it { is_expected.to run.with_params(1, []).and_raise_error(ArgumentError, %r{parameter 'charset' expects a String value, got Array}) }
+  it { is_expected.to run.with_params(1, {}).and_raise_error(ArgumentError, %r{parameter 'charset' expects a String value, got Hash}) }
+  it { is_expected.to run.with_params('100').and_raise_error(ArgumentError, %r{parameter 'length' expects an Integer value, got String}) }
+  it { is_expected.to run.with_params(100, nil).and_raise_error(ArgumentError, %r{parameter 'charset' expects a String value, got Undef}) }
   it { is_expected.to run.with_params(100).and_return(default_charset) }
-  it { is_expected.to run.with_params('100').and_return(default_charset) }
-  it { is_expected.to run.with_params(100, nil).and_return(default_charset) }
   it { is_expected.to run.with_params(100, '').and_return(default_charset) }
   it { is_expected.to run.with_params(100, 'a').and_return(%r{\Aa{100}\z}) }
   it { is_expected.to run.with_params(100, 'ab').and_return(%r{\A[ab]{100}\z}) }
   it { is_expected.to run.with_params(100, 'ãβ').and_return(%r{\A[ãβ]{100}\z}) }
 
-  it "provides the same 'random' value on subsequent calls for the same host" do
-    expect(fqdn_rand_string(10)).to eql(fqdn_rand_string(10))
-  end
-
-  it 'considers the same host and same extra arguments to have the same random sequence' do
-    first_random = fqdn_rand_string(10, extra_identifier: [1, 'same', 'host'])
-    second_random = fqdn_rand_string(10, extra_identifier: [1, 'same', 'host'])
-
-    expect(first_random).to eql(second_random)
-  end
-
-  it 'allows extra arguments to control the random value on a single host' do
-    first_random = fqdn_rand_string(10, extra_identifier: [1, 'different', 'host'])
-    second_different_random = fqdn_rand_string(10, extra_identifier: [2, 'different', 'host'])
-
-    expect(first_random).not_to eql(second_different_random)
-  end
-
-  it 'returns different strings for different hosts' do
-    val1 = fqdn_rand_string(10, host: 'first.host.com')
-    val2 = fqdn_rand_string(10, host: 'second.host.com')
-
-    expect(val1).not_to eql(val2)
-  end
+  context 'produce predictible and reproducible results' do
+    before(:each) do
+      if Gem::Version.new(Puppet::PUPPETVERSION) < Gem::Version.new('7.23.0')
+        allow(scope).to receive(:lookupvar).with('::fqdn', {}).and_return(fqdn)
+      else
+        allow(scope).to receive(:lookupvar).with('facts', {}).and_return({ 'networking' => { 'fqdn' => fqdn } })
+      end
+    end
 
-  def fqdn_rand_string(max, args = {})
-    host = args[:host] || '127.0.0.1'
-    charset = args[:charset]
-    extra = args[:extra_identifier] || []
+    context 'on a node named example.com' do
+      let(:fqdn) { 'example.com' }
 
-    # workaround not being able to use let(:facts) because some tests need
-    # multiple different hostnames in one context
-    if Gem::Version.new(Puppet::PUPPETVERSION) < Gem::Version.new('7.23.0')
-      allow(scope).to receive(:lookupvar).with('::fqdn', {}).and_return(host)
-    else
-      allow(scope).to receive(:lookupvar).with('facts', {}).and_return({ 'networking' => { 'fqdn' => host } })
+      it { is_expected.to run.with_params(5).and_return('Pw5NP') }
+      it { is_expected.to run.with_params(10, 'abcd').and_return('cdadaaacaa') }
+      it { is_expected.to run.with_params(20, '', 'custom seed').and_return('3QKQHP4wmEObY3a6hkeg') }
+      it { is_expected.to run.with_params(20, '', 'custom seed', 1, 'extra').and_return('OA19SVDoc3QPY5NlSQ28') }
     end
 
-    function_args = [max]
-    if args.key?(:charset) || !extra.empty?
-      function_args << charset
+    context 'on a node named desktop-fln40kq.lan' do
+      let(:fqdn) { 'desktop-fln40kq.lan' }
+
+      it { is_expected.to run.with_params(5).and_return('bgQsB') }
+      it { is_expected.to run.with_params(10, 'abcd').and_return('bcdbcdacad') }
+      it { is_expected.to run.with_params(20, '', 'custom seed').and_return('KaZsFlWkUo5SeA3gBEf0') }
+      it { is_expected.to run.with_params(20, '', 'custom seed', 1, 'extra').and_return('dcAzn1e8AA7hhoLpxAD6') }
     end
-    function_args += extra
-    scope.function_fqdn_rand_string(function_args)
   end
 end