Give easy instructions for small modifications to the default compone…

…nts.

* Rename _LEAPP_DEFAULT_COMPONENTS to GET_LEAPP_PACKAGES_DEFAULT_COMPONENTS (More descriptive name
  and no longer private)
* Add instructions for modifying the default value of the component parameter to the
  get_leapp_packages and get_leapp_deps_packages docstrings

repos/system_upgrade/common/libraries/rpms.py

@@ -37,9 +37,9 @@ class LeappComponents(object):
                                 }
         }
 
-_LEAPP_DEFAULT_COMPONENTS = frozenset((LeappComponents.FRAMEWORK,
-                            LeappComponents.REPOSITORY,
-                            LeappComponents.TOOLS))
+GET_LEAPP_PACKAGES_DEFAULT_COMPONENTS = frozenset((LeappComponents.FRAMEWORK,
+                                                   LeappComponents.REPOSITORY,
+                                                   LeappComponents.TOOLS))
 
 
 def get_installed_rpms():
@@ -203,7 +203,7 @@ def _get_leapp_packages_of_type(major_version, component, type_='pkgs'):
     return sorted(res)
 
 
-def get_leapp_packages(major_version=None, component=_LEAPP_DEFAULT_COMPONENTS):
+def get_leapp_packages(major_version=None, component=GET_LEAPP_PACKAGES_DEFAULT_COMPONENTS):
     """
     Get list of leapp packages.
 
@@ -212,6 +212,15 @@ def get_leapp_packages(major_version=None, component=_LEAPP_DEFAULT_COMPONENTS):
     :param component: a list or a single enum value specifying leapp components
         (use enum :class: LeappComponents) If defined then only packages related to the specific
         component(s) will be returned.
+        The default set of components is in `GET_LEAPP_PACKAGES_DEFAULT_COMPONENTS` and
+        simple modifications of the default can be achieved with code like:
+
+        .. code-block:: python
+            get_leapp_packages(
+                component=GET_LEAPP_PACKAGES_DEFAULT_COMPONENTS.difference(
+                    [LeappComponents.TOOLS]
+            ))
+
     :raises ValueError: if a requested component or major_version doesn't exist.
 
     .. note::
@@ -224,7 +233,7 @@ def get_leapp_packages(major_version=None, component=_LEAPP_DEFAULT_COMPONENTS):
     return _get_leapp_packages_of_type(major_version, component, type_="pkgs")
 
 
-def get_leapp_dep_packages(major_version=None, component=_LEAPP_DEFAULT_COMPONENTS):
+def get_leapp_dep_packages(major_version=None, component=GET_LEAPP_PACKAGES_DEFAULT_COMPONENTS):
     """
     Get list of leapp dep metapackages.
 
@@ -233,6 +242,14 @@ def get_leapp_dep_packages(major_version=None, component=_LEAPP_DEFAULT_COMPONEN
     :param component: a list or a single enum value specifying leapp components
         (use enum :class: LeappComponents) If defined then only packages related to the specific
         component(s) will be returned.
+        The default set of components is in `GET_LEAPP_PACKAGES_DEFAULT_COMPONENTS` and
+        simple modifications of the default can be achieved with code like:
+
+        .. code-block:: python
+            get_leapp_packages(
+                component=GET_LEAPP_PACKAGES_DEFAULT_COMPONENTS.difference(
+                    [LeappComponents.TOOLS]
+            ))
     :raises ValueError: if a requested component or major_version doesn't exist.
     """
     return _get_leapp_packages_of_type(major_version, component, type_="deps")