Schema-based Operator Relation Libraries
Project description
sborl - Schema-based Operator Relation Libraries
This library provides a base for creating relation endpoint libraries for use with charmed operators and Juju. It tries to make creating Pythonic implementations of a relation interface protocol straightforward and approachable, while encouraging good patterns such as using schema-based interface protocol validation, providing helpers for testing charms using your library, and surfacing problems with relations in a clean way.
Example
An example endpoint class and usage might look like:
class RandomURLRequirer(sborl.relation.EndpointWrapper):
INTERFACE = "random-url"
ROLE = "requires"
SCHEMA = Path(__file__) / "schema.yaml"
LIMIT = 1
@property
def url(self):
if not self.is_ready():
return None
relation = self.relations[0]
return self.unwrap(relation)[relation.app]["url"]
class MyCharm(ops.charm.CharmBase):
def __init__(self, *args):
super().__init__(*args)
self.random_url = RandomURLRequirer(charm=self, endpoint="random-url-provider")
self.framework.observe(self.random_url.on.ready, self._log_url)
def _log_url(self, event):
log.info(f"Got random URL: {self.random_url.url}")