set none for db migration config. easier deployment

Author: kiyo9w

backend/app/core/config.py

@@ -51,23 +51,46 @@ def all_cors_origins(self) -> list[str]:
 
     PROJECT_NAME: str
     SENTRY_DSN: HttpUrl | None = None
-    POSTGRES_SERVER: str
-    POSTGRES_PORT: int = 5432
-    POSTGRES_USER: str
-    POSTGRES_PASSWORD: str = ""
-    POSTGRES_DB: str = ""
+
+    # Add DATABASE_URL as an optional field
+    DATABASE_URL: PostgresDsn | None = None
+
+    # Make individual PG fields optional
+    POSTGRES_SERVER: str | None = None
+    POSTGRES_PORT: int | None = 5432
+    POSTGRES_USER: str | None = None
+    POSTGRES_PASSWORD: str | None = None
+    POSTGRES_DB: str | None = None
 
     @computed_field  # type: ignore[prop-decorator]
     @property
     def SQLALCHEMY_DATABASE_URI(self) -> PostgresDsn:
-        return MultiHostUrl.build(
-            scheme="postgresql+psycopg",
-            username=self.POSTGRES_USER,
-            password=self.POSTGRES_PASSWORD,
-            host=self.POSTGRES_SERVER,
-            port=self.POSTGRES_PORT,
-            path=self.POSTGRES_DB,
-        )
+        if self.DATABASE_URL:
+            print("Using DATABASE_URL from environment")
+            return self.DATABASE_URL
+        elif (
+            self.POSTGRES_SERVER
+            and self.POSTGRES_USER
+            # Password can be None or empty
+            and self.POSTGRES_DB
+            and self.POSTGRES_PORT
+        ):
+            print("Using individual POSTGRES variables from environment")
+            # Ensure password is a string, even if None was provided
+            pg_password = self.POSTGRES_PASSWORD or ""
+            return MultiHostUrl.build(
+                scheme="postgresql+psycopg",
+                username=self.POSTGRES_USER,
+                password=pg_password,
+                host=self.POSTGRES_SERVER,
+                port=self.POSTGRES_PORT,
+                path=self.POSTGRES_DB,
+            )
+        else:
+            raise ValueError(
+                "Database configuration error: Set DATABASE_URL or all individual "
+                "POSTGRES_SERVER, POSTGRES_USER, POSTGRES_PASSWORD, POSTGRES_DB, POSTGRES_PORT variables."
+            )
 
     SMTP_TLS: bool = True
     SMTP_SSL: bool = False
@@ -109,7 +132,9 @@ def _check_default_secret(self, var_name: str, value: str | None) -> None:
     @model_validator(mode="after")
     def _enforce_non_default_secrets(self) -> Self:
         self._check_default_secret("SECRET_KEY", self.SECRET_KEY)
-        self._check_default_secret("POSTGRES_PASSWORD", self.POSTGRES_PASSWORD)
+        # Only check PG password if individual variables are used
+        if not self.DATABASE_URL and self.POSTGRES_PASSWORD:
+            self._check_default_secret("POSTGRES_PASSWORD", self.POSTGRES_PASSWORD)
         self._check_default_secret(
             "FIRST_SUPERUSER_PASSWORD", self.FIRST_SUPERUSER_PASSWORD
         )