use pydantic settings (#657)

* use pydantic settings

* rename stac_fastapi_id to stac_fastapi_landing_id

stac_fastapi/api/stac_fastapi/api/app.py

@@ -1,5 +1,5 @@
 """Fastapi app creation."""
-import os
+
 from typing import Any, Dict, List, Optional, Tuple, Type, Union
 
 import attr
@@ -84,11 +84,21 @@ class StacApi:
         converter=update_openapi,
     )
     router: APIRouter = attr.ib(default=attr.Factory(APIRouter))
-    title: str = attr.ib(default=os.getenv("STAC_FASTAPI_TITLE", "stac-fastapi"))
-    api_version: str = attr.ib(default=os.getenv("STAC_FASTAPI_VERSION", "0.1"))
+    title: str = attr.ib(
+        default=attr.Factory(
+            lambda self: self.settings.stac_fastapi_title, takes_self=True
+        )
+    )
+    api_version: str = attr.ib(
+        default=attr.Factory(
+            lambda self: self.settings.stac_fastapi_version, takes_self=True
+        )
+    )
     stac_version: str = attr.ib(default=STAC_VERSION)
     description: str = attr.ib(
-        default=os.getenv("STAC_FASTAPI_DESCRIPTION", "stac-fastapi")
+        default=attr.Factory(
+            lambda self: self.settings.stac_fastapi_description, takes_self=True
+        )
     )
     search_get_request_model: Type[BaseSearchGetRequest] = attr.ib(
         default=BaseSearchGetRequest

stac_fastapi/types/stac_fastapi/types/config.py

@@ -22,6 +22,11 @@ class ApiSettings(BaseSettings):
     # `pydantic.BaseSettings` instead
     default_includes: Optional[Set[str]] = None
 
+    stac_fastapi_title: str = "stac-fastapi"
+    stac_fastapi_description: str = "stac-fastapi"
+    stac_fastapi_version: str = "0.1"
+    stac_fastapi_landing_id: str = "stac-fastapi"
+
     app_host: str = "0.0.0.0"
     app_port: int = 8000
     reload: bool = True

stac_fastapi/types/stac_fastapi/types/core.py

@@ -1,7 +1,6 @@
 """Base clients."""
 
 import abc
-import os
 from typing import Any, Dict, List, Optional, Union
 from urllib.parse import urljoin
 
@@ -13,6 +12,7 @@
 from starlette.responses import Response
 
 from stac_fastapi.types import stac as stac_types
+from stac_fastapi.types.config import ApiSettings
 from stac_fastapi.types.conformance import BASE_CONFORMANCE_CLASSES
 from stac_fastapi.types.extension import ApiExtension
 from stac_fastapi.types.requests import get_base_url
@@ -23,6 +23,8 @@
 NumType = Union[float, int]
 StacType = Dict[str, Any]
 
+api_settings = ApiSettings()
+
 
 @attr.s  # type:ignore
 class BaseTransactionsClient(abc.ABC):
@@ -256,11 +258,9 @@ class LandingPageMixin(abc.ABC):
     """Create a STAC landing page (GET /)."""
 
     stac_version: str = attr.ib(default=STAC_VERSION)
-    landing_page_id: str = attr.ib(default=os.getenv("STAC_FASTAPI_ID", "0.1"))
-    title: str = attr.ib(default=os.getenv("STAC_FASTAPI_TITLE", "stac-fastapi"))
-    description: str = attr.ib(
-        default=os.getenv("STAC_FASTAPI_DESCRIPTION", "stac-fastapi")
-    )
+    landing_page_id: str = attr.ib(default=api_settings.stac_fastapi_landing_id)
+    title: str = attr.ib(default=api_settings.stac_fastapi_title)
+    description: str = attr.ib(default=api_settings.stac_fastapi_description)
 
     def _landing_page(
         self,