vyos.configdict: T5308: Remove workarounds for incorrect defaults in get_interface_dict

[jestabro]

Change Summary

Note: this depends on PR:
#2010

Applying the revised vyos.xml lib (T5218) to get_config_dict, one can remove the workarounds needed in get_interface_dict due to incorrect defaults on tag nodes (bug T2665).

The original implementation of the vyos.xml lib adds defaults below a tag node name, irrespective of the existence of a corresponding tag node value, and at the wrong level; this required workarounds to delete and/or shift defaults before merging dicts.

That bug is corrected in the revision of the vyos.xml lib, merged in T5218.

As a first step, we remove the workarounds in vyos.configdict.get_interface_dict; this provides the same results without the workaround overhead, passes all smoketests and config tests. As get_interface_dict is a critical part of the vyos lib infrastructure, it is addressed first and as a separate task. Removing all other cases of T2665 workarounds will follow directly.

Note that for compatibility this maintains the practice of merging 'recursive' defaults in get_interface_dict --- namely, those leaf nodes with default values that have an ancestor node in the config are merged into the result. The revisions to the xml lib and get_config_dict also support providing 'non-recursive' defaults: those that have a parent in the config; cf. the discussion of invariants in PR #2010, above. We can consider maintaining this invariant going forward.

Example, exhibiting the bug corrected in the second commit, below:

vyos@vyos# show interfaces ethernet eth1
+address dhcpv6
+dhcpv6-options {
+    parameters-only
+}
 hw-id 52:54:00:7b:3e:08
>>> from vyos.config import Config
>>> from vyos.orig_configdict import get_interface_dict as orig_get_interface_dict
>>> from vyos.configdict import get_interface_dict
>>> from pprint import pprint
>>> conf = Config()
>>> base = ['interfaces', 'ethernet']
>>> _, orig = orig_get_interface_dict(conf, base, ifname='eth1')
>>> _, rev = get_interface_dict(conf, base, ifname='eth1')
>>> _, rev_local = get_interface_dict(conf, base, ifname='eth1', recursive_defaults=False)
>>> pprint(dict(sorted(orig.items())))
{'address': ['dhcpv6'],
 'dhcpv6_options': {'parameters_only': {}, 'pd': {}},
 'duplex': 'auto',
 'hw_id': '52:54:00:7b:3e:08',
 'ifname': 'eth1',
 'ip': {'arp_cache_timeout': '30'},
 'mtu': '1500',
 'speed': 'auto'}
>>> pprint(dict(sorted(rev.items())))
{'address': ['dhcpv6'],
 'dhcpv6_options': {'parameters_only': {}},
 'duplex': 'auto',
 'hw_id': '52:54:00:7b:3e:08',
 'ifname': 'eth1',
 'ip': {'arp_cache_timeout': '30'},
 'mtu': '1500',
 'speed': 'auto'}
>>> pprint(dict(sorted(rev_local.items())))
{'address': ['dhcpv6'],
 'dhcpv6_options': {'parameters_only': {}},
 'duplex': 'auto',
 'hw_id': '52:54:00:7b:3e:08',
 'ifname': 'eth1',
 'mtu': '1500',
 'speed': 'auto'}

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

• https://vyos.dev/T5308
• https://vyos.dev/T5228

Component(s) name

Proposed changes

How to test

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[c-po]

Yeah! always looked forward to it! Thanks @jestabro