Update helloworld to be more clear about parameters.

software/helloworld/instance.cfg.in

@@ -18,8 +18,13 @@ offline = true
 
 
 [instance-parameter]
-# Fetches parameters defined in SlapOS Master for this instance.
-# Always the same.
+# Fetch arbitrary parameters defined by the user in SlapOS Master for his instance.
+# We use the slapconfiguration recipe with a few parameters (partition id,
+# computer id, certificate, etc).
+# It will then authenticate to SlapOS Master and fetch the instance parameters.
+# The parameters are accessible from $${instance-parameter:configuration.name-of-parameter}
+# Always the same. Just copy/paste.
+# See docstring of slapos.cookbook:slapconfiguration for more informations.
 recipe = slapos.cookbook:slapconfiguration
 computer = $${slap_connection:computer_id}
 partition = $${slap_connection:partition_id}
@@ -28,10 +33,13 @@ key = $${slap_connection:key_file}
 cert = $${slap_connection:cert_file}
 
 # Define default parameter(s) that will be used later, in case user didn't
-# specify it
-# All parameters are available through the configuration.XX syntax.
+# specify it.
 # All possible parameters should have a default.
-configuration.name = anonymous
+# In our use case, we are expecting from the user to specify one (optional) parameter: "name". We put the default value here if he doesn't specify it, so that it doesn't crash.
+configuration.name = John Doe
+# If our use case requires that the user can specify a mail address so that his instance can mail to him (for example), we can do:
+# configuration.mail-address =
+# If the user doesn't specify it, it won't break and the recipe can handle it (i.e don't send any mail for example).
 
 
 # Create all needed directories, depending on your needs

software/helloworld/software.cfg

@@ -25,6 +25,6 @@ parts =
 recipe = slapos.recipe.template
 url = ${:_profile_base_location_}/instance.cfg.in
 output = ${buildout:directory}/instance.cfg
-# MD5 checksum can be skipped for development, but must be filled for production
-#md5sum = 
+# MD5 checksum can be skipped for development (easier to develop), but must be filled for production
+md5sum = 1fc461c00e86485bee77a942f39e3c43
 mode = 0644