feat(client): Support client cookies

src/lsst/cmservice/client/client.py

@@ -41,6 +41,12 @@ def __init__(self: CMClient) -> None:
             client_kwargs["headers"] = {"Authorization": f"Bearer {client_config.auth_token}"}
         if "timeout" in client_config.model_fields_set:  # pragma: no cover
             client_kwargs["timeout"] = client_config.timeout
+        if "cookies" in client_config.model_fields_set:  # pragma: no cover
+            cookies = httpx.Cookies()
+            if client_config.cookies:
+                for cookie in client_config.cookies:
+                    cookies.set(name=cookie.name, value=cookie.value)
+            client_kwargs["cookies"] = cookies
         self._client = httpx.Client(**client_kwargs)
 
         self.production = CMProductionClient(self)

src/lsst/cmservice/client/clientconfig.py

@@ -1,11 +1,16 @@
 from typing import Any
 
-from pydantic import Field, field_validator
+from pydantic import BaseModel, Field, field_validator
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
 __all__ = ["ClientConfiguration", "client_config"]
 
 
+class ClientCookie(BaseModel):
+    name: str
+    value: str
+
+
 class ClientConfiguration(BaseSettings):
     """Configuration for cm-client."""
 
@@ -21,6 +26,14 @@ class ClientConfiguration(BaseSettings):
         validation_alias="CM_TOKEN",
     )
 
+    cookies: list[ClientCookie] | None = Field(
+        description=(
+            "Comma separated list of pipe-separated cookie names and values, e.g., `name|value,name|value`"
+        ),
+        default=None,
+        validation_alias="CM_COOKIES",
+    )
+
     timeout: float | None = Field(
         default=None,
         validation_alias="CM_TIMEOUT",
@@ -34,6 +47,13 @@ def validate_timeout(cls, v: Any) -> float | None:
             return None
         return v
 
+    @field_validator("cookies", mode="before", check_fields=True)
+    @classmethod
+    def validate_cookies(cls, v: Any) -> list[ClientCookie] | None:
+        if v is None:  # pragma: no cover
+            return v
+        return [ClientCookie(name=n, value=v) for n, v in [a.split("|") for a in v.split(",")]]
+
 
 client_config = ClientConfiguration()
 """Configuration for cm-client."""