feat(shared): add config trailing slash sanitizer (#1870)

shared/libretime_shared/config.py

@@ -1,19 +1,23 @@
 import sys
 from os import environ
 from pathlib import Path
-from typing import Any, Dict, List, Optional, Union
+from typing import TYPE_CHECKING, Any, Dict, List, Optional, Union
 
 from loguru import logger
 
 # pylint: disable=no-name-in-module
-from pydantic import AnyHttpUrl, BaseModel, ValidationError
+from pydantic import AnyHttpUrl, BaseModel, ValidationError, validator
 from pydantic.fields import ModelField
 from pydantic.utils import deep_update
 from yaml import YAMLError, safe_load
 
+if TYPE_CHECKING:
+    from pydantic.typing import AnyClassMethod
+
 DEFAULT_ENV_PREFIX = "LIBRETIME"
 DEFAULT_CONFIG_FILEPATH = Path("/etc/libretime/config.yml")
 
+
 # pylint: disable=too-few-public-methods
 class BaseConfig(BaseModel):
     """
@@ -103,16 +107,30 @@ class BaseConfig(BaseModel):
         return {}
 
 
+def no_trailing_slash_validator(key: str) -> "AnyClassMethod":
+    # pylint: disable=unused-argument
+    def strip_trailing_slash(cls: Any, value: str) -> str:
+        return value.rstrip("/")
+
+    return validator(key, pre=True, allow_reuse=True)(strip_trailing_slash)
+
+
 # pylint: disable=too-few-public-methods
 class GeneralConfig(BaseModel):
     public_url: AnyHttpUrl
     api_key: str
 
+    # Validators
+    _public_url_no_trailing_slash = no_trailing_slash_validator("public_url")
+
 
 # pylint: disable=too-few-public-methods
 class StorageConfig(BaseModel):
     path: str = "/srv/libretime"
 
+    # Validators
+    _path_no_trailing_slash = no_trailing_slash_validator("path")
+
 
 # pylint: disable=too-few-public-methods
 class DatabaseConfig(BaseModel):