SX cap production setup files

lib/capistrano/substitute_strings.rb

@@ -0,0 +1,12 @@
+# we often want to refer to variables which
+# are defined in subsequent stage files. This
+# let's us use the {{var}} to represent fetch(:var)
+# in strings which are only evaluated at runtime.
+
+def sub_strings(input_string)
+  output_string = input_string
+  input_string.scan(/{{(\w*)}}/).each do |var|
+    output_string.gsub!("{{#{var[0]}}}", fetch(var[0].to_sym))
+  end
+  output_string
+end