Document that extra kernel parameters are important for inspection

When customising kolla_bifrost_inspector_extra_kernel_options, for
example to define which console to use, operators should note that
Kayobe defines extra kernel parameters that are important for
inspection, such as ipa-collect-lldp=1.

Change-Id: Id789dede2d1886ef5ec66ebc86968d6cf62fa2de

ansible/group_vars/all/bifrost

@@ -87,6 +87,9 @@ kolla_bifrost_inspector_processing_hooks: "{{ inspector_processing_hooks }}"
 kolla_bifrost_inspector_port_addition: "{{ inspector_add_ports }}"
 
 # List of extra kernel parameters for the inspector default PXE configuration.
+# Default is {{ inspector_extra_kernel_options }}, defined in inspector.yml.
+# When customising this variable, the default extra kernel parameters should be
+# kept to retain full node inspection capabilities.
 kolla_bifrost_inspector_extra_kernel_options: "{{ inspector_extra_kernel_options }}"
 
 # List of introspection rules for Bifrost's Ironic Inspector service.

doc/source/configuration/reference/bifrost.rst

@@ -227,7 +227,9 @@ The following options configure the Ironic Inspector service in the
 ``kolla_bifrost_inspector_extra_kernel_options``
     List of extra kernel parameters for the inspector default PXE
     configuration. Default is ``{{ inspector_extra_kernel_options }}``, defined
-    in ``${KAYOBE_CONFIG_PATH}/inspector.yml``.
+    in ``${KAYOBE_CONFIG_PATH}/inspector.yml``. When customising this variable,
+    the default extra kernel parameters should be kept to retain full node
+    inspection capabilities.
 ``kolla_bifrost_inspector_rules``
     List of introspection rules for Bifrost's Ironic Inspector service. Default
     is ``{{ inspector_rules }}``, defined in

etc/kayobe/bifrost.yml

@@ -86,6 +86,9 @@
 #kolla_bifrost_inspector_port_addition:
 
 # List of extra kernel parameters for the inspector default PXE configuration.
+# Default is {{ inspector_extra_kernel_options }}, defined in inspector.yml.
+# When customising this variable, the default extra kernel parameters should be
+# kept to retain full node inspection capabilities.
 #kolla_bifrost_inspector_extra_kernel_options:
 
 # List of introspection rules for Bifrost's Ironic Inspector service.