Replace usage of uriescape

The uriescape function from puppetlabs-stdlib is no longer functional
in Puppet 8, because the URI.escape, which is internally used by that
function, is no longer available in Ruby 3+.

This replaces the function by own function to avoid the failure in
Puppet 8.

Closes-Bug: #2057860
Change-Id: I7b4db4c1e64416e20d8470cbff0b8497c6a0cfc9

lib/puppet/functions/encode_url_queries_for_python.rb

@@ -0,0 +1,19 @@
+Puppet::Functions.create_function(:encode_url_queries_for_python) do
+
+  def encode_url_queries_for_python(*args)
+    require 'uri'
+
+    if (args.size != 1) then
+      raise Puppet::ParseError, 'encode_url_queries_for_python(): Wrong number of arguments'
+    end
+    queries = args[0]
+    if list.class != Hash
+      raise Puppet::ParseError, "Syntax error: #{args[0]} is not a Hash"
+    end
+
+    if queries.empty?
+      return ''
+    end
+    return '?' + URI.encode_www_form(queries).gsub(/%/, '%%')
+  end
+end

manifests/migration/libvirt.pp

@@ -233,13 +233,7 @@ class nova::migration::libvirt(
       $postfix = ''
     }
 
-    if empty($client_extraparams) {
-      $extra_params =''
-    } else {
-      $extra_params_before_python_escape = join(uriescape(join_keys_to_values($client_extraparams, '=')), '&')
-      # Must escape % as nova interprets it incorrectly.
-      $extra_params = sprintf('?%s', regsubst($extra_params_before_python_escape, '%', '%%', 'G'))
-    }
+    extra_params = encode_url_queries_for_python($client_extraparams)
 
     $live_migration_uri = "qemu+${transport}://${prefix}%s${postfix}/system${extra_params}"