charm-interface-neutron-plugin/provides.py
Liam Young 677f1a666a Reuse existing metadata secret if present
If there is an existing metadata secret stored on the filesystem
then reuse it to ensure a smooth transition from the old provider
to the new.

Closes-Bug: #1916609
Change-Id: I74f889f0fc13f0bde2677054f7acaed63a46aea6
2021-04-29 14:32:49 +00:00

60 lines
1.8 KiB
Python

import json
import os
import uuid
from charms.reactive import hook
from charms.reactive import RelationBase
from charms.reactive import scopes
METADATA_KEY = 'metadata-shared-secret'
LEGACY_SECRET_FILE = "/etc/neutron/secret.txt"
class NeutronPluginProvides(RelationBase):
scope = scopes.GLOBAL
@hook('{provides:neutron-plugin}-relation-{joined,changed}')
def changed(self):
self.set_state('{relation_name}.connected')
@hook('{provides:neutron-plugin}-relation-{broken,departed}')
def broken(self):
self.remove_state('{relation_name}.connected')
def configure_plugin(self, plugin, config):
conversation = self.conversation()
relation_info = {
'neutron-plugin': plugin,
'subordinate_configuration': json.dumps(config),
}
conversation.set_remote(**relation_info)
def get_or_create_shared_secret(self):
"""Retrieves a shared secret from local unit storage.
The secret is created if it does not already exist.
:returns: Shared secret
:rtype: str
"""
secret = self.get_local(METADATA_KEY)
if secret is None:
# If the secrets file is present then reuse the secret to ensure
# compatability with the existing setup.
if os.path.exists(LEGACY_SECRET_FILE):
with open(LEGACY_SECRET_FILE, 'r') as secret_file:
secret = secret_file.read().strip()
else:
secret = str(uuid.uuid4())
self.set_local(METADATA_KEY, secret)
return secret
def publish_shared_secret(self):
"""Publish the shared secret on the relation."""
conversation = self.conversation()
relation_info = {
METADATA_KEY: self.get_or_create_shared_secret(),
}
conversation.set_remote(**relation_info)