Add anaconda configuration and template

This change adds 'anaconda' group and 'default_ks_template'
configuration option under that group to ironic configuration file.
Along with this change a new boot_option named 'kickstart' is added
to identify anaconda kickstart deploy in the boot interface.

deploy_utils.get_boot_option method is modified to check if
node.deploy_interface is set to 'anaconda' and return boot_option
'kickstart'.

This change also validates whether required parameters are set when
the boot_option on the node is set to 'kickstart'.

When boot_option is 'kickstart' we also validate if the glance image
source has 'squashfs_id' property associated with it.

Change-Id: I2ef7c33e2e63e6d08c084b4c5dbd77a44ddd2d14
Story: 2007839
Task: 41675

ironic/conf/anaconda.py

@@ -0,0 +1,36 @@
+# Copyright 2021 Verizon Media
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+import os
+
+from oslo_config import cfg
+
+from ironic.common.i18n import _
+
+
+ks_group = cfg.OptGroup(name='anaconda',
+                        title='Anaconda/kickstart interface options')
+opts = [
+    cfg.StrOpt('default_ks_template',
+               default=os.path.join(
+                   '$pybasedir', 'drivers/modules/ks.cfg.template'),
+               mutable=True,
+               help=_('kickstart template to use when no kickstart template '
+                      'is specified in the instance_info or the glance OS '
+                      'image.')),
+]
+
+
+def register_opts(conf):
+    conf.register_group(ks_group)
+    conf.register_opts(opts, group='anaconda')