Allow limiting physical network interface configuration to subsets

Allow the physical network interface configuration to be limited to a subset of
interfaces, either by interface name or switch interface description. This is done
via:

kayobe physical network configure --interface-limit interface1,interface2

or

kayobe physical network configure --interface-description-limit host1,host2

Fixes: #25

ansible/filter_plugins/switches.py

@@ -15,6 +15,22 @@
 import six
 
 
+def switch_interface_config_select_name(switch_interface_config, names):
+    """Select and return all switch interfaces matching requested names.
+
+    :param switch_interface_config: Switch interface configuration dict
+    :param names: String or list of strings - interface names to match
+    """
+    if isinstance(names, six.string_types):
+        names = [names]
+
+    return {
+        name: config
+        for name, config in switch_interface_config.items()
+        if name in names
+    }
+
+
 def switch_interface_config_select_description(switch_interface_config, descriptions):
     """Select and return all switch interfaces matching requested descriptions.
 
@@ -32,10 +48,27 @@ def switch_interface_config_select_description(switch_interface_config, descript
     }
 
 
+def switch_interface_config_select_trunk(switch_interface_config):
+    """Select and return all switch interfaces which are trunk links.
+
+    Interfaces are assumed to be trunked, unless they have a ngs_trunk_port
+    item which is set to False.
+
+    :param switch_interface_config: Switch interface configuration dict
+    """
+    return {
+        name: config
+        for name, config in switch_interface_config.items()
+        if config.get('ngs_trunk_port', True)
+    }
+
+
 class FilterModule(object):
     """Switch filters."""
 
     def filters(self):
         return {
+            'switch_interface_config_select_name': switch_interface_config_select_name,
             'switch_interface_config_select_description': switch_interface_config_select_description,
+            'switch_interface_config_select_trunk': switch_interface_config_select_trunk,
         }

ansible/kolla-openstack.yml

@@ -134,7 +134,8 @@
                     'password': hostvars[item].ansible_ssh_pass,
                     'ngs_trunk_ports': (
                          hostvars[item].switch_interface_config |
-                         switch_interface_config_select_description(kolla_neutron_ml2_generic_switch_trunk_port_hosts)).keys() | join(',')
+                         switch_interface_config_select_description(kolla_neutron_ml2_generic_switch_trunk_port_hosts) |
+                         switch_interface_config_select_trunk()).keys() | join(',')
                   }]
               }}
           with_items: "{{ kolla_neutron_ml2_generic_switch_hosts }}"

ansible/physical-network.yml

@@ -2,13 +2,30 @@
 # Switch configuration depends on the type of switch, so groups hosts by their
 # switch type and apply tasks/roles to the relevant groups.
 
-- name: Group hosts by their switch type
+- name: Group hosts by their switch type and apply configuration filters
   hosts: switches
   gather_facts: no
   vars:
-    # Set this variable to True to configure of network for hardware discovery.
+    # Set this variable to True to configure the network for hardware
+    # discovery.
     physical_network_enable_discovery: False
+    # Set this variable to a comma-separated list of names of interfaces to
+    # configure in order to restrict configuration to a subset of interfaces.
+    physical_network_interface_limit: ''
+    # Set this variable to a comma-separated list of descriptions of interfaces
+    # to configure in order to restrict configuration to a subset of
+    # interfaces.
+    physical_network_interface_description_limit: ''
   tasks:
+    - name: Fail if both interface name and description limits are specified
+      fail:
+        msg: >
+          The interface name and interface description limits are mutually
+          exclusive.
+      when:
+        - physical_network_interface_limit != ''
+        - physical_network_interface_description_limit != ''
+
     - name: Group hosts by their switch type
       group_by:
         key: "switches_of_type_{{ switch_type }}"
@@ -19,6 +36,20 @@
           {{ switch_interface_config | combine(switch_interface_config_discovery) }}
       when: "{{ physical_network_enable_discovery | bool }}"
 
+    - name: Restrict switch interfaces to requested subset by name
+      set_fact:
+        switch_interface_config: >
+          {{ switch_interface_config |
+             switch_interface_config_select_name(physical_network_interface_limit.split(",")) }}
+      when: physical_network_interface_limit != ''
+
+    - name: Restrict switch interfaces to requested subset by description
+      set_fact:
+        switch_interface_config: >
+          {{ switch_interface_config |
+             switch_interface_config_select_description(physical_network_interface_description_limit.split(",")) }}
+      when: physical_network_interface_description_limit != ''
+
 - name: Ensure DellOS physical switches are configured
   hosts: switches_of_type_dellos6:switches_of_type_dellos9
   gather_facts: no

doc/source/deployment.rst

@@ -40,6 +40,16 @@ The ``--enable-discovery`` argument enables a one-time configuration of ports
 attached to baremetal compute nodes to support hardware discovery via ironic
 inspector.
 
+It is possible to limit the switch interfaces that will be configured, either
+by interface name or interface description::
+
+    (kayobe) $ kayobe physical network configure --group <group> --interface-limit <interface names>
+    (kayobe) $ kayobe physical network configure --group <group> --interface-description-limit <interface descriptions>
+
+The names or descriptions should be separated by commas.  This may be useful
+when adding compute nodes to an existing deployment, in order to avoid changing
+the configuration interfaces in use by active nodes.
+
 Seed Hypervisor
 ===============
 

doc/source/release-notes.rst

@@ -5,6 +5,13 @@ Release Notes
 In Development
 ==============
 
+Features
+--------
+
+* Adds ``--interface-limit`` and ``--interface-description-limit`` arguments to
+  the ``kayobe physical network configure`` command.  These arguments allow
+  configuration to be limited to a subset of switch interfaces.
+
 Upgrade Notes
 -------------
 

kayobe/cli/commands.py

@@ -229,6 +229,12 @@ class PhysicalNetworkConfigure(KayobeAnsibleMixin, VaultMixin, Command):
                            help="the Ansible group to apply configuration to")
         group.add_argument("--enable-discovery", action="store_true",
                            help="configure the network for hardware discovery")
+        group.add_argument("--interface-limit",
+                           help="limit the switch interfaces to be configured "
+                                "by interface name")
+        group.add_argument("--interface-description-limit",
+                           help="limit the switch interfaces to be configured "
+                                "by interface description")
         return parser
 
     def take_action(self, parsed_args):
@@ -236,6 +242,12 @@ class PhysicalNetworkConfigure(KayobeAnsibleMixin, VaultMixin, Command):
         extra_vars = {}
         if parsed_args.enable_discovery:
             extra_vars["physical_network_enable_discovery"] = True
+        if parsed_args.interface_limit:
+            extra_vars["physical_network_interface_limit"] = (
+                parsed_args.interface_limit)
+        if parsed_args.interface_description_limit:
+            extra_vars["physical_network_interface_description_limit"] = (
+                parsed_args.interface_description_limit)
         self.run_kayobe_playbook(parsed_args, "ansible/physical-network.yml",
                                  limit=parsed_args.group,
                                  extra_vars=extra_vars)