[VM & K8S] MongoDBProvider duplicates information in databag and is error-prone

[phvalguima]

Looking into MongoDBProvider class, I can see it registers the same information for each user twice, where username, database, hosts, password and replset are registered as variables and as part of the URI in the databag.

That means any change in the charm code must take into consideration that both the configuration itself and the URI must be updated as either maybe used.

That is passed in the mongodb provider:

class MongoDBProvider(Object):

...

    def _set_relation(self, config: MongoDBConfiguration):
        """Save all output fields into application relation."""
        relation = self._get_relation_from_username(config.username)
        if relation is None:
            return None

        data = relation.data[self.charm.app]
        data["username"] = config.username
        data["password"] = config.password
        data["database"] = config.database
        data["endpoints"] = ",".join(config.hosts)
        data["replset"] = config.replset
        data["uris"] = config.uri
        relation.data[self.charm.app].update(data)

And the MongoDBConfiguration code:

class MongoDBConfiguration:

...

    replset: str
    database: Optional[str]
    username: str
    password: str
    hosts: Set[str]
    roles: Set[str]
    tls_external: bool
    tls_internal: bool

    @property
    def uri(self):
        """Return URI concatenated from fields."""
        hosts = ",".join(self.hosts)
        # Auth DB should be specified while user connects to application DB.
        auth_source = ""
        if self.database != "admin":
            auth_source = "&authSource=admin"
        return (
            f"mongodb://{quote_plus(self.username)}:"
            f"{quote_plus(self.password)}@"
            f"{hosts}/{quote_plus(self.database)}?"
            f"replicaSet={quote_plus(self.replset)}"
            f"{auth_source}"
        )

[github-actions]

https://warthogs.atlassian.net/browse/DPE-2275