♻️ Refactor and update config.py

Author: tiangolo

backend/app/api/routes/users.py

@@ -60,7 +60,7 @@ def create_user(*, session: SessionDep, user_in: UserCreate) -> Any:
         )
 
     user = crud.create_user(session=session, user_create=user_in)
-    if settings.EMAILS_ENABLED and user_in.email:
+    if settings.emails_enabled and user_in.email:
         email_data = generate_new_account_email(
             email_to=user_in.email, username=user_in.email, password=user_in.password
         )

backend/app/core/config.py

@@ -1,95 +1,92 @@
 import secrets
-from typing import Any
+from typing import Annotated, Any, Literal
 
 from pydantic import (
-    AnyHttpUrl,
+    AnyUrl,
+    BeforeValidator,
     HttpUrl,
     PostgresDsn,
-    ValidationInfo,
-    field_validator,
+    computed_field,
+    model_validator,
 )
+from pydantic_core import MultiHostUrl
 from pydantic_settings import BaseSettings, SettingsConfigDict
+from typing_extensions import Self
+
+
+def parse_cors(v: Any) -> list[str] | str:
+    if isinstance(v, str) and not v.startswith("["):
+        return [i.strip() for i in v.split(",")]
+    elif isinstance(v, list | str):
+        return v
+    raise ValueError(v)
 
 
 class Settings(BaseSettings):
+    model_config = SettingsConfigDict(env_file=".env", env_ignore_empty=True)
     API_V1_STR: str = "/api/v1"
     SECRET_KEY: str = secrets.token_urlsafe(32)
     # 60 minutes * 24 hours * 8 days = 8 days
     ACCESS_TOKEN_EXPIRE_MINUTES: int = 60 * 24 * 8
-    SERVER_HOST: AnyHttpUrl
-    BACKEND_CORS_ORIGINS: list[AnyHttpUrl] | str = []
-
-    @field_validator("BACKEND_CORS_ORIGINS", mode="before")
-    @classmethod
-    def assemble_cors_origins(cls, v: str | list[str]) -> list[str] | str:
-        if isinstance(v, str) and not v.startswith("["):
-            return [i.strip() for i in v.split(",")]
-        elif isinstance(v, list | str):
-            return v
-        raise ValueError(v)
+    DOMAIN: str = "localhost"
+    HOST_SCHEME: Literal["https", "http"] = "http"
 
-    PROJECT_NAME: str
-    SENTRY_DSN: HttpUrl | None = None
+    @computed_field  # type: ignore[misc]
+    @property
+    def server_host(self) -> str:
+        return f"{self.HOST_SCHEME}://{self.DOMAIN}"
 
-    @field_validator("SENTRY_DSN", mode="before")
-    @classmethod
-    def sentry_dsn_can_be_blank(cls, v: str) -> str | None:
-        if not v:
-            return None
-        return v
+    BACKEND_CORS_ORIGINS: Annotated[
+        list[AnyUrl] | str, BeforeValidator(parse_cors)
+    ] = []
 
+    PROJECT_NAME: str
+    SENTRY_DSN: HttpUrl | None = None
     POSTGRES_SERVER: str
     POSTGRES_USER: str
     POSTGRES_PASSWORD: str
-    POSTGRES_DB: str
-    SQLALCHEMY_DATABASE_URI: PostgresDsn | None = None
-
-    @field_validator("SQLALCHEMY_DATABASE_URI", mode="before")
-    def assemble_db_connection(cls, v: str | None, info: ValidationInfo) -> Any:
-        if isinstance(v, str):
-            return v
-        return PostgresDsn.build(
+    POSTGRES_DB: str = ""
+
+    @computed_field  # type: ignore[misc]
+    @property
+    def SQLALCHEMY_DATABASE_URI(self) -> PostgresDsn:
+        return MultiHostUrl.build(
             scheme="postgresql+psycopg",
-            username=info.data.get("POSTGRES_USER"),
-            password=info.data.get("POSTGRES_PASSWORD"),
-            host=info.data.get("POSTGRES_SERVER"),
-            path=f"{info.data.get('POSTGRES_DB') or ''}",
+            username=self.POSTGRES_USER,
+            password=self.POSTGRES_PASSWORD,
+            host=self.POSTGRES_SERVER,
+            path=self.POSTGRES_DB,
         )
 
     SMTP_TLS: bool = True
-    SMTP_PORT: int | None = None
+    SMTP_PORT: int = 587
     SMTP_HOST: str | None = None
     SMTP_USER: str | None = None
     SMTP_PASSWORD: str | None = None
     # TODO: update type to EmailStr when sqlmodel supports it
     EMAILS_FROM_EMAIL: str | None = None
     EMAILS_FROM_NAME: str | None = None
 
-    @field_validator("EMAILS_FROM_NAME")
-    def get_project_name(cls, v: str | None, info: ValidationInfo) -> str:
-        if not v:
-            return str(info.data["PROJECT_NAME"])
-        return v
+    @model_validator(mode="after")
+    def set_default_emails_from(self) -> Self:
+        if not self.EMAILS_FROM_NAME:
+            self.EMAILS_FROM_NAME = self.PROJECT_NAME
+        return self
 
     EMAIL_RESET_TOKEN_EXPIRE_HOURS: int = 48
     EMAIL_TEMPLATES_DIR: str = "/app/app/email-templates/build"
-    EMAILS_ENABLED: bool = False
-
-    @field_validator("EMAILS_ENABLED", mode="before")
-    def get_emails_enabled(cls, v: bool, info: ValidationInfo) -> bool:
-        return bool(
-            info.data.get("SMTP_HOST")
-            and info.data.get("SMTP_PORT")
-            and info.data.get("EMAILS_FROM_EMAIL")
-        )
+
+    @computed_field  # type: ignore[misc]
+    @property
+    def emails_enabled(self) -> bool:
+        return bool(self.SMTP_HOST and self.EMAILS_FROM_EMAIL)
 
     # TODO: update type to EmailStr when sqlmodel supports it
     EMAIL_TEST_USER: str = "test@example.com"
     # TODO: update type to EmailStr when sqlmodel supports it
     FIRST_SUPERUSER: str
     FIRST_SUPERUSER_PASSWORD: str
     USERS_OPEN_REGISTRATION: bool = False
-    model_config = SettingsConfigDict(env_file=".env")
 
 
 settings = Settings()  # type: ignore

backend/app/utils.py

@@ -17,7 +17,7 @@ class EmailData:
     subject: str
 
 
-def render_email_template(*, template_name: str, context: dict[str, Any]):
+def render_email_template(*, template_name: str, context: dict[str, Any]) -> str:
     template_str = (Path(settings.EMAIL_TEMPLATES_DIR) / template_name).read_text()
     html_content = Template(template_str).render(context)
     return html_content
@@ -29,7 +29,7 @@ def send_email(
     subject: str = "",
     html_content: str = "",
 ) -> None:
-    assert settings.EMAILS_ENABLED, "no provided configuration for email variables"
+    assert settings.emails_enabled, "no provided configuration for email variables"
     message = emails.Message(
         subject=subject,
         html=html_content,
@@ -59,8 +59,7 @@ def generate_test_email(email_to: str) -> EmailData:
 def generate_reset_password_email(email_to: str, email: str, token: str) -> EmailData:
     project_name = settings.PROJECT_NAME
     subject = f"{project_name} - Password recovery for user {email}"
-    server_host = settings.SERVER_HOST
-    link = f"{server_host}/reset-password?token={token}"
+    link = f"{settings.server_host}/reset-password?token={token}"
     html_content = render_email_template(
         template_name="reset_password.html",
         context={
@@ -79,15 +78,14 @@ def generate_new_account_email(
 ) -> EmailData:
     project_name = settings.PROJECT_NAME
     subject = f"{project_name} - New account for user {username}"
-    link = settings.SERVER_HOST
     html_content = render_email_template(
         template_name="new_account.html",
         context={
             "project_name": settings.PROJECT_NAME,
             "username": username,
             "password": password,
             "email": email_to,
-            "link": link,
+            "link": settings.server_host,
         },
     )
     return EmailData(html_content=html_content, subject=subject)