chore(charm): Update Redis relation to be able to use HA

examples/django/charm/lib/charms/grafana_k8s/v0/grafana_dashboard.py

@@ -219,7 +219,7 @@ def __init__(self, *args):
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
 
-LIBPATCH = 35
+LIBPATCH = 36
 
 logger = logging.getLogger(__name__)
 
@@ -1050,6 +1050,7 @@ def __init__(
 
         self.framework.observe(self._charm.on.leader_elected, self._update_all_dashboards_from_dir)
         self.framework.observe(self._charm.on.upgrade_charm, self._update_all_dashboards_from_dir)
+        self.framework.observe(self._charm.on.config_changed, self._update_all_dashboards_from_dir)
 
         self.framework.observe(
             self._charm.on[self._relation_name].relation_created,

examples/django/charm/lib/charms/loki_k8s/v1/loki_push_api.py

@@ -480,6 +480,25 @@ def _alert_rules_error(self, event):
 
 Units of consumer charm send their alert rules over app relation data using the `alert_rules`
 key.
+
+## Charm logging
+The `charms.loki_k8s.v0.charm_logging` library can be used in conjunction with this one to configure python's
+logging module to forward all logs to Loki via the loki-push-api interface.
+
+```python
+from lib.charms.loki_k8s.v0.charm_logging import log_charm
+from lib.charms.loki_k8s.v1.loki_push_api import charm_logging_config, LokiPushApiConsumer
+
+@log_charm(logging_endpoint="my_endpoints", server_cert="cert_path")
+class MyCharm(...):
+    _cert_path = "/path/to/cert/on/charm/container.crt"
+    def __init__(self, ...):
+        self.logging = LokiPushApiConsumer(...)
+        self.my_endpoints, self.cert_path = charm_logging_config(
+            self.logging, self._cert_path)
+```
+
+Do this, and all charm logs will be forwarded to Loki as soon as a relation is formed.
 """
 
 import json
@@ -527,7 +546,7 @@ def _alert_rules_error(self, event):
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
-LIBPATCH = 12
+LIBPATCH = 13
 
 PYDEPS = ["cosl"]
 
@@ -577,7 +596,11 @@ def _alert_rules_error(self, event):
 GRPC_LISTEN_PORT_START = 9095  # odd start port
 
 
-class RelationNotFoundError(ValueError):
+class LokiPushApiError(Exception):
+    """Base class for errors raised by this module."""
+
+
+class RelationNotFoundError(LokiPushApiError):
     """Raised if there is no relation with the given name."""
 
     def __init__(self, relation_name: str):
@@ -587,7 +610,7 @@ def __init__(self, relation_name: str):
         super().__init__(self.message)
 
 
-class RelationInterfaceMismatchError(Exception):
+class RelationInterfaceMismatchError(LokiPushApiError):
     """Raised if the relation with the given name has a different interface."""
 
     def __init__(
@@ -607,7 +630,7 @@ def __init__(
         super().__init__(self.message)
 
 
-class RelationRoleMismatchError(Exception):
+class RelationRoleMismatchError(LokiPushApiError):
     """Raised if the relation with the given name has a different direction."""
 
     def __init__(
@@ -2555,7 +2578,7 @@ def _on_pebble_ready(self, event: PebbleReadyEvent):
 
         self._update_endpoints(event.workload, loki_endpoints)
 
-    def _update_logging(self, _):
+    def _update_logging(self, event: RelationEvent):
         """Update the log forwarding to match the active Loki endpoints."""
         if not (loki_endpoints := self._retrieve_endpoints_from_relation()):
             logger.warning("No Loki endpoints available")
@@ -2566,6 +2589,8 @@ def _update_logging(self, _):
                 self._update_endpoints(container, loki_endpoints)
             # else: `_update_endpoints` will be called on pebble-ready anyway.
 
+        self._handle_alert_rules(event.relation)
+
     def _retrieve_endpoints_from_relation(self) -> dict:
         loki_endpoints = {}
 
@@ -2750,3 +2775,49 @@ def _exec(self, cmd) -> str:
         result = subprocess.run(cmd, check=True, stdout=subprocess.PIPE)
         output = result.stdout.decode("utf-8").strip()
         return output
+
+
+def charm_logging_config(
+    endpoint_requirer: LokiPushApiConsumer, cert_path: Optional[Union[Path, str]]
+) -> Tuple[Optional[List[str]], Optional[str]]:
+    """Utility function to determine the charm_logging config you will likely want.
+
+    If no endpoint is provided:
+     disable charm logging.
+    If https endpoint is provided but cert_path is not found on disk:
+     disable charm logging.
+    If https endpoint is provided and cert_path is None:
+     ERROR
+    Else:
+     proceed with charm logging (with or without tls, as appropriate)
+
+    Args:
+        endpoint_requirer: an instance of LokiPushApiConsumer.
+        cert_path: a path where a cert is stored.
+
+    Returns:
+        A tuple with (optionally) the values of the endpoints and the certificate path.
+
+    Raises:
+         LokiPushApiError: if some endpoint are http and others https.
+    """
+    endpoints = [ep["url"] for ep in endpoint_requirer.loki_endpoints]
+    if not endpoints:
+        return None, None
+
+    https = tuple(endpoint.startswith("https://") for endpoint in endpoints)
+
+    if all(https):  # all endpoints are https
+        if cert_path is None:
+            raise LokiPushApiError("Cannot send logs to https endpoints without a certificate.")
+        if not Path(cert_path).exists():
+            # if endpoints is https BUT we don't have a server_cert yet:
+            # disable charm logging until we do to prevent tls errors
+            return None, None
+        return endpoints, str(cert_path)
+
+    if all(not x for x in https):  # all endpoints are http
+        return endpoints, None
+
+    # if there's a disagreement, that's very weird:
+    raise LokiPushApiError("Some endpoints are http, some others are https. That's not good.")

examples/django/charm/lib/charms/redis_k8s/v0/redis.py

@@ -39,7 +39,7 @@
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version.
-LIBPATCH = 6
+LIBPATCH = 7
 
 logger = logging.getLogger(__name__)
 
@@ -78,6 +78,18 @@ def _on_relation_broken(self, event):
         # Trigger an event that our charm can react to.
         self.charm.on.redis_relation_updated.emit()
 
+    @property
+    def app_data(self) -> Optional[Dict[str, str]]:
+        """Retrieve the app data.
+
+        Returns:
+            Dict: dict containing the app data.
+        """
+        relation = self.model.get_relation(self.relation_name)
+        if not relation:
+            return None
+        return relation.data[relation.app]
+
     @property
     def relation_data(self) -> Optional[Dict[str, str]]:
         """Retrieve the relation data.
@@ -98,10 +110,16 @@ def url(self) -> Optional[str]:
         Returns:
             str: the Redis URL.
         """
-        relation_data = self.relation_data
-        if not relation_data:
+        if not (relation_data := self.relation_data):
             return None
+
         redis_host = relation_data.get("hostname")
+
+        if app_data := self.app_data:
+            try:
+                redis_host = self.app_data.get("leader-host", redis_host)
+            except KeyError:
+                pass
         redis_port = relation_data.get("port")
         return f"redis://{redis_host}:{redis_port}"
 

examples/django/charm/lib/charms/traefik_k8s/v2/ingress.py

@@ -56,13 +56,14 @@ def _on_ingress_revoked(self, event: IngressPerAppRevokedEvent):
 import socket
 import typing
 from dataclasses import dataclass
+from functools import partial
 from typing import Any, Callable, Dict, List, MutableMapping, Optional, Sequence, Tuple, Union
 
 import pydantic
 from ops.charm import CharmBase, RelationBrokenEvent, RelationEvent
 from ops.framework import EventSource, Object, ObjectEvents, StoredState
 from ops.model import ModelError, Relation, Unit
-from pydantic import AnyHttpUrl, BaseModel, Field, validator
+from pydantic import AnyHttpUrl, BaseModel, Field
 
 # The unique Charmhub library identifier, never change it
 LIBID = "e6de2a5cd5b34422a204668f3b8f90d2"
@@ -72,7 +73,7 @@ def _on_ingress_revoked(self, event: IngressPerAppRevokedEvent):
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
-LIBPATCH = 13
+LIBPATCH = 14
 
 PYDEPS = ["pydantic"]
 
@@ -84,6 +85,9 @@ def _on_ingress_revoked(self, event: IngressPerAppRevokedEvent):
 
 PYDANTIC_IS_V1 = int(pydantic.version.VERSION.split(".")[0]) < 2
 if PYDANTIC_IS_V1:
+    from pydantic import validator
+
+    input_validator = partial(validator, pre=True)
 
     class DatabagModel(BaseModel):  # type: ignore
         """Base databag model."""
@@ -143,7 +147,9 @@ def dump(self, databag: Optional[MutableMapping] = None, clear: bool = True):
             return databag
 
 else:
-    from pydantic import ConfigDict
+    from pydantic import ConfigDict, field_validator
+
+    input_validator = partial(field_validator, mode="before")
 
     class DatabagModel(BaseModel):
         """Base databag model."""
@@ -171,7 +177,7 @@ def load(cls, databag: MutableMapping):
                     k: json.loads(v)
                     for k, v in databag.items()
                     # Don't attempt to parse model-external values
-                    if k in {(f.alias or n) for n, f in cls.__fields__.items()}  # type: ignore
+                    if k in {(f.alias or n) for n, f in cls.model_fields.items()}  # type: ignore
                 }
             except json.JSONDecodeError as e:
                 msg = f"invalid databag contents: expecting json. {databag}"
@@ -252,14 +258,14 @@ class IngressRequirerAppData(DatabagModel):
         default="http", description="What scheme to use in the generated ingress url"
     )
 
-    @validator("scheme", pre=True)
+    @input_validator("scheme")
     def validate_scheme(cls, scheme):  # noqa: N805  # pydantic wants 'cls' as first arg
         """Validate scheme arg."""
         if scheme not in {"http", "https", "h2c"}:
             raise ValueError("invalid scheme: should be one of `http|https|h2c`")
         return scheme
 
-    @validator("port", pre=True)
+    @input_validator("port")
     def validate_port(cls, port):  # noqa: N805  # pydantic wants 'cls' as first arg
         """Validate port."""
         assert isinstance(port, int), type(port)
@@ -277,13 +283,13 @@ class IngressRequirerUnitData(DatabagModel):
         "IP can only be None if the IP information can't be retrieved from juju.",
     )
 
-    @validator("host", pre=True)
+    @input_validator("host")
     def validate_host(cls, host):  # noqa: N805  # pydantic wants 'cls' as first arg
         """Validate host."""
         assert isinstance(host, str), type(host)
         return host
 
-    @validator("ip", pre=True)
+    @input_validator("ip")
     def validate_ip(cls, ip):  # noqa: N805  # pydantic wants 'cls' as first arg
         """Validate ip."""
         if ip is None:
@@ -462,7 +468,10 @@ def _handle_relation(self, event):
                 event.relation,
                 data.app.name,
                 data.app.model,
-                [unit.dict() for unit in data.units],
+                [
+                    unit.dict() if PYDANTIC_IS_V1 else unit.model_dump(mode="json")
+                    for unit in data.units
+                ],
                 data.app.strip_prefix or False,
                 data.app.redirect_https or False,
             )

examples/fastapi/charm/lib/charms/data_platform_libs/v0/data_interfaces.py

@@ -331,7 +331,7 @@ def _on_topic_requested(self, event: TopicRequestedEvent):
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
-LIBPATCH = 39
+LIBPATCH = 40
 
 PYDEPS = ["ops>=2.0.0"]
 
@@ -391,6 +391,10 @@ class IllegalOperationError(DataInterfacesError):
     """To be used when an operation is not allowed to be performed."""
 
 
+class PrematureDataAccessError(DataInterfacesError):
+    """To be raised when the Relation Data may be accessed (written) before protocol init complete."""
+
+
 ##############################################################################
 # Global helpers / utilities
 ##############################################################################
@@ -1453,6 +1457,8 @@ def _on_relation_changed_event(self, event: RelationChangedEvent) -> None:
 class ProviderData(Data):
     """Base provides-side of the data products relation."""
 
+    RESOURCE_FIELD = "database"
+
     def __init__(
         self,
         model: Model,
@@ -1618,6 +1624,15 @@ def _fetch_my_specific_relation_data(
     def _update_relation_data(self, relation: Relation, data: Dict[str, str]) -> None:
         """Set values for fields not caring whether it's a secret or not."""
         req_secret_fields = []
+
+        keys = set(data.keys())
+        if self.fetch_relation_field(relation.id, self.RESOURCE_FIELD) is None and (
+            keys - {"endpoints", "read-only-endpoints", "replset"}
+        ):
+            raise PrematureDataAccessError(
+                "Premature access to relation data, update is forbidden before the connection is initialized."
+            )
+
         if relation.app:
             req_secret_fields = get_encoded_list(relation, relation.app, REQ_SECRET_FIELDS)
 
@@ -3290,6 +3305,8 @@ class KafkaRequiresEvents(CharmEvents):
 class KafkaProviderData(ProviderData):
     """Provider-side of the Kafka relation."""
 
+    RESOURCE_FIELD = "topic"
+
     def __init__(self, model: Model, relation_name: str) -> None:
         super().__init__(model, relation_name)
 
@@ -3539,6 +3556,8 @@ class OpenSearchRequiresEvents(CharmEvents):
 class OpenSearchProvidesData(ProviderData):
     """Provider-side of the OpenSearch relation."""
 
+    RESOURCE_FIELD = "index"
+
     def __init__(self, model: Model, relation_name: str) -> None:
         super().__init__(model, relation_name)