Fix Pydantic warnings. (#388)

* Fix Pydantic warnings.

Pydantic has deprecated validator and should be replaced by field_validator.

See https://docs.pydantic.dev/2.8/migration/#validator-and-root_validator-are-deprecated

* Use `partial` for validators

* Replace `__fields__` with `model_fields`.

This was deprecated in v2. This instance of `__fields__` was called within a block that only runs in pydantic v2, so it should be fine to replace the function call.

* Fix the rest of pydantic warnings.

* Bump LIBPATCH on tracing and ingress

---------

Co-authored-by: PietroPasotti <[email protected]>

lib/charms/tempo_k8s/v2/tracing.py

@@ -107,7 +107,7 @@ 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 = 7
+LIBPATCH = 8
 
 PYDEPS = ["pydantic"]
 
@@ -174,7 +174,8 @@ class AmbiguousRelationUsageError(TracingError):
     """Raised when one wrongly assumes that there can only be one relation on an endpoint."""
 
 
-if int(pydantic.version.VERSION.split(".")[0]) < 2:
+PYDANTIC_IS_V1 = int(pydantic.version.VERSION.split(".")[0]) < 2
+if PYDANTIC_IS_V1:
 
     class DatabagModel(BaseModel):  # type: ignore
         """Base databag model."""
@@ -312,7 +313,7 @@ def dump(self, databag: Optional[MutableMapping] = None, clear: bool = True):
 
 
 # todo use models from charm-relation-interfaces
-if int(pydantic.version.VERSION.split(".")[0]) < 2:
+if PYDANTIC_IS_V1:
 
     class ProtocolType(BaseModel):  # type: ignore
         """Protocol Type."""
@@ -865,7 +866,10 @@ def _on_tracing_relation_changed(self, event):
             return
 
         data = TracingProviderAppData.load(relation.data[relation.app])
-        self.on.endpoint_changed.emit(relation, [i.dict() for i in data.receivers])  # type: ignore
+        self.on.endpoint_changed.emit(
+            relation,
+            [i.dict() if PYDANTIC_IS_V1 else i.model_dump(mode="json") for i in data.receivers],
+        )
 
     def _on_tracing_relation_broken(self, event: RelationBrokenEvent):
         """Notify the providers that the endpoint is broken."""

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,
             )

src/charm.py

@@ -13,6 +13,7 @@
 from typing import Any, Dict, List, Optional, Tuple, Union, cast
 from urllib.parse import urlparse
 
+import pydantic
 import yaml
 from charms.certificate_transfer_interface.v0.certificate_transfer import (
     CertificateAvailableEvent as CertificateTransferAvailableEvent,
@@ -32,14 +33,15 @@
     ForwardAuthRequirerConfig,
 )
 from charms.observability_libs.v1.cert_handler import CertHandler
-from charms.observability_libs.v1.kubernetes_service_patch import (
-    KubernetesServicePatch,
-)
+from charms.observability_libs.v1.kubernetes_service_patch import KubernetesServicePatch
 from charms.prometheus_k8s.v0.prometheus_scrape import MetricsEndpointProvider
 from charms.tempo_k8s.v1.charm_tracing import trace_charm
 from charms.tempo_k8s.v2.tracing import TracingEndpointRequirer
 from charms.traefik_k8s.v1.ingress import IngressPerAppProvider as IPAv1
-from charms.traefik_k8s.v1.ingress_per_unit import DataValidationError, IngressPerUnitProvider
+from charms.traefik_k8s.v1.ingress_per_unit import (
+    DataValidationError,
+    IngressPerUnitProvider,
+)
 from charms.traefik_k8s.v2.ingress import IngressPerAppProvider as IPAv2
 from charms.traefik_route_k8s.v0.traefik_route import (
     TraefikRouteProvider,
@@ -88,6 +90,8 @@
 
 _TRAEFIK_CONTAINER_NAME = "traefik"
 
+PYDANTIC_IS_V1 = int(pydantic.version.VERSION.split(".")[0]) < 2
+
 
 class _IngressRelationType(enum.Enum):
     per_app = "per_app"
@@ -931,7 +935,9 @@ def _get_configs_per_app(self, relation: Relation) -> Dict[str, Any]:
             logger.error(f"invalid data shared through {relation}... Error: {e}.")
             return {}
 
-        prefix = self._get_prefix(data.app.dict(by_alias=True))
+        prefix = self._get_prefix(
+            data.app.dict(by_alias=True) if PYDANTIC_IS_V1 else data.app.model_dump(by_alias=True)
+        )
         config = self.traefik.get_per_app_http_config(
             prefix=prefix,
             scheme=data.app.scheme,