Convert redisget to redis::get API v4 function

Since we'll be dropping puppet 3 support in the next release, we should
move away from using legacy functions that suffer from environment
isolation issues.

See https://puppet.com/docs/puppet/4.10/functions_legacy.html

The newer function API also has built in support for validating function
arguments, declaring some parameters as optional etc.  This allows us to
remove a lot of our own code that was performing this validation before.

Fixes voxpupuli#291

README.md

@@ -104,28 +104,13 @@ class { '::redis::sentinel':
 }
 ```
 
-## `redisget()` function
-
-`redisget()` takes two or three arguments that are strings. The first is the key
-to be looked up, the second is the URL to the Redis service and the
-optional third argument is a default value to use if the key is not
-found or connection to the Redis service cannot be made.
-
-Example of basic usage.
-
-```puppet
-$version = redisget('version.myapp', 'redis://redis.example.com:6379')
-```
-
-Example with default value specified. This is useful to allow for cached
-data in case Redis is not available.
-
-```puppet
-$version = redisget('version.myapp', 'redis://redis.example.com:6379', $::myapp_version)
-```
+## `redis::get()` function
 
+This function is used to get data from redis.
 You must have the 'redis' gem installed on your puppet master.
 
+Functions are documented in [REFERENCE.md](REFERENCE.md)
+
 ## Unit testing
 
 Plain RSpec:

REFERENCE.md

@@ -0,0 +1,61 @@
+# Reference
+<!-- DO NOT EDIT: This document was generated by Puppet Strings -->
+
+## Table of Contents
+
+**Functions**
+
+* [`redis::get`](#redisget): Returns the value of the key being looked up or `undef` if the key does not exist. Takes two arguments with an optional third. The first bein
+
+## Functions
+
+### redis::get
+
+Type: Ruby 4.x API
+
+Returns the value of the key being looked up or `undef` if the key does not
+exist. Takes two arguments with an optional third. The first being a string
+value of the key to be looked up, the second is the URL to the Redis service
+and the third optional argument is a default value to be used if the lookup
+fails.
+
+example usage
+```
+$version = redis::get('version.myapp', 'redis://redis.example.com:6379')
+$version_with_default = redis::get('version.myapp', 'redis://redis.example.com:6379', $::myapp_version)
+```
+
+#### `redis::get(String[1] $key, Redis::RedisUrl $url, Optional[String] $default)`
+
+Returns the value of the key being looked up or `undef` if the key does not
+exist. Takes two arguments with an optional third. The first being a string
+value of the key to be looked up, the second is the URL to the Redis service
+and the third optional argument is a default value to be used if the lookup
+fails.
+
+example usage
+```
+$version = redis::get('version.myapp', 'redis://redis.example.com:6379')
+$version_with_default = redis::get('version.myapp', 'redis://redis.example.com:6379', $::myapp_version)
+```
+
+Returns: `Optional[String]` Returns the value of the key from Redis
+
+##### `key`
+
+Data type: `String[1]`
+
+The key to look up in redis
+
+##### `url`
+
+Data type: `Redis::RedisUrl`
+
+The endpoint of the Redis instance
+
+##### `default`
+
+Data type: `Optional[String]`
+
+The value to return if the key is not found or the connection to Redis fails
+

lib/puppet/functions/redis/get.rb

@@ -0,0 +1,32 @@
+require 'redis'
+# Returns the value of the key being looked up or `undef` if the key does not
+# exist. Takes two arguments with an optional third. The first being a string
+# value of the key to be looked up, the second is the URL to the Redis service
+# and the third optional argument is a default value to be used if the lookup
+# fails.
+#
+# example usage
+# ```
+# $version = redis::get('version.myapp', 'redis://redis.example.com:6379')
+# $version_with_default = redis::get('version.myapp', 'redis://redis.example.com:6379', $::myapp_version)
+# ```
+Puppet::Functions.create_function(:'redis::get') do
+  # @param key The key to look up in redis
+  # @param url The endpoint of the Redis instance
+  # @param default The value to return if the key is not found or the connection to Redis fails
+  # @return Returns the value of the key from Redis
+  dispatch :get do
+    param 'String[1]', :key
+    param 'Redis::RedisUrl', :url
+    optional_param 'String', :default
+    return_type 'Optional[String]'
+  end
+
+  def get(key, url, default = nil)
+    Redis.new(url: url).get(key) || default
+  rescue Redis::CannotConnectError, SocketError => e
+    raise Puppet::Error, "connection to redis server failed - #{e}" unless default
+    Puppet.debug "Connection to redis failed with #{e} - Returning default value of #{default}"
+    default
+  end
+end

spec/acceptance/suites/default/redisget_spec.rb

@@ -1,14 +1,14 @@
 # rubocop:disable RSpec/MultipleExpectations
 require 'spec_helper_acceptance'
 
-describe 'redisget() function' do
+describe 'redis::get() function' do
   it 'runs successfully' do
     pp = <<-EOS
     Exec {
       path => [ '/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin', ]
     }
 
-    class { '::redis':
+    class { 'redis':
       manage_repo => true,
     }
 
@@ -33,9 +33,9 @@ class { '::redis':
     end
   end
 
-  it 'returns a value from MyKey with the redisget() function' do
+  it 'returns a value from MyKey with the redis::get() function' do
     pp = <<-EOS
-    $mykey = redisget('mykey', 'redis://127.0.0.1:6379')
+    $mykey = redis::get('mykey', 'redis://127.0.0.1:6379')
 
     notify{"mykey value: ${mykey}":}
     EOS
@@ -46,9 +46,9 @@ class { '::redis':
     end
   end
 
-  it 'returns a value from valid MyKey with the redisget() function while specifying a default' do
+  it 'returns a value from valid MyKey with the redis::get() function while specifying a default' do
     pp = <<-EOS
-    $mykey = redisget('mykey', 'redis://127.0.0.1:6379', 'default_value')
+    $mykey = redis::get('mykey', 'redis://127.0.0.1:6379', 'default_value')
 
     notify{"mykey value: ${mykey}":}
     EOS
@@ -59,9 +59,9 @@ class { '::redis':
     end
   end
 
-  it 'returns an empty string when value not present with redisget() function' do
+  it 'returns an empty string when value not present with redis::get() function' do
     pp = <<-EOS
-    $foo_key = redisget('foo', 'redis://127.0.0.1:6379')
+    $foo_key = redis::get('foo', 'redis://127.0.0.1:6379')
 
     if empty($foo_key){
       notify{"foo_key value was empty string":}
@@ -74,9 +74,9 @@ class { '::redis':
     end
   end
 
-  it 'returns the specified default value when key not present with redisget() function' do
+  it 'returns the specified default value when key not present with redis::get() function' do
     pp = <<-EOS
-    $foo_key = redisget('foo', 'redis://127.0.0.1:6379', 'default_value')
+    $foo_key = redis::get('foo', 'redis://127.0.0.1:6379', 'default_value')
 
     notify { $foo_key: }
     EOS
@@ -90,7 +90,7 @@ class { '::redis':
   it 'returns the specified default value when connection to redis server fails' do
     pp = <<-EOS
     # Bogus port for redis server
-    $foo_key = redisget('foo', 'redis://127.0.0.1:12345', 'default_value')
+    $foo_key = redis::get('foo', 'redis://127.0.0.1:12345', 'default_value')
 
     notify { $foo_key: }
     EOS
@@ -104,7 +104,7 @@ class { '::redis':
   it 'returns an error when specifying a non connectable redis server' do
     pp = <<-EOS
     # Bogus port for redis server
-    $foo_key = redisget('foo', 'redis://127.0.0.1:12345')
+    $foo_key = redis::get('foo', 'redis://127.0.0.1:12345')
 
     notify { $foo_key: }
     EOS

spec/functions/redisget_spec.rb → spec/functions/redis/get_spec.rb

@@ -6,7 +6,7 @@
 LOCAL_BROKEN_URL = 'redis://localhost:1234'.freeze
 REMOTE_BROKEN_URL = 'redis://redis.example.com:1234'.freeze
 
-describe 'redisget' do
+describe 'redis::get' do
   context 'should error if connection to remote redis server cannot be made and no default is specified' do
     it { is_expected.to run.with_params('nonexistent_key', REMOTE_BROKEN_URL).and_raise_error(Puppet::Error, %r{connection to redis server failed - Error connecting to Redis on redis.example.com:1234 \(SocketError\)}) }
   end
@@ -59,15 +59,15 @@
 
   describe 'with incorrect arguments' do
     context 'with no argument specified' do
-      it { is_expected.to run.with_params.and_raise_error(Puppet::ParseError, %r{wrong number of arguments}i) }
+      it { is_expected.to run.with_params.and_raise_error(ArgumentError) }
     end
 
     context 'with only one argument specified' do
-      it { is_expected.to run.with_params('some_key').and_raise_error(Puppet::ParseError, %r{wrong number of arguments}i) }
+      it { is_expected.to run.with_params('some_key').and_raise_error(ArgumentError) }
     end
 
     context 'with more than three arguments specified' do
-      it { is_expected.to run.with_params('way', 'too', 'many', 'args').and_raise_error(Puppet::ParseError, %r{wrong number of arguments}i) }
+      it { is_expected.to run.with_params('way', 'too', 'many', 'args').and_raise_error(ArgumentError) }
     end
   end
 
@@ -78,15 +78,15 @@
     end
     [{ 'ha' => 'sh' }, true, 1, %w[an array]].each do |p|
       context "specifing first parameter as <#{p}>" do
-        it { is_expected.to run.with_params(p, REDIS_URL).and_raise_error(Puppet::ParseError, %r{wrong argument type}i) }
+        it { is_expected.to run.with_params(p, REDIS_URL).and_raise_error(ArgumentError) }
       end
 
       context "specifing second parameter as <#{p}>" do
-        it { is_expected.to run.with_params('valid', p).and_raise_error(Puppet::ParseError, %r{wrong argument type}i) }
+        it { is_expected.to run.with_params('valid', p).and_raise_error(ArgumentError) }
       end
 
       context "specifing third parameter as <#{p}>" do
-        it { is_expected.to run.with_params('valid', p).and_raise_error(Puppet::ParseError, %r{wrong argument type}i) }
+        it { is_expected.to run.with_params('valid', p).and_raise_error(ArgumentError) }
       end
     end
   end

types/redisurl.pp

@@ -0,0 +1 @@
+type Redis::RedisUrl = Pattern[/(^redis:\/\/)/]