feat: Add env var ENV_MAX_LIMIT for items returned

This PR adds a environment variable ENV_MAX_LIMIT, which allows overriding the default MAX_LIMIT value,
which controls the ?limit URL parameter used in STAC API queries, defining the maximum number of items
and collections that can be returned in a single response.

Author: Yuri Zmytrakov

stac_fastapi/core/stac_fastapi/core/utilities.py

@@ -10,7 +10,15 @@
 
 from stac_fastapi.types.stac import Item
 
-MAX_LIMIT = 10000
+
+def get_max_limit():
+    """
+    Retrieve a MAX_LIMIT value from an environment variable.
+
+    Returns:
+        int: The int value parsed from the environment variable.
+    """
+    return int(os.getenv("ENV_MAX_LIMIT", 10000))
 
 
 def get_bool_env(name: str, default: Union[bool, str] = False) -> bool:

stac_fastapi/elasticsearch/stac_fastapi/elasticsearch/database_logic.py

@@ -17,7 +17,7 @@
 
 from stac_fastapi.core.base_database_logic import BaseDatabaseLogic
 from stac_fastapi.core.serializers import CollectionSerializer, ItemSerializer
-from stac_fastapi.core.utilities import MAX_LIMIT, bbox2polygon
+from stac_fastapi.core.utilities import bbox2polygon, get_max_limit
 from stac_fastapi.elasticsearch.config import AsyncElasticsearchSettings
 from stac_fastapi.elasticsearch.config import (
     ElasticsearchSettings as SyncElasticsearchSettings,
@@ -543,7 +543,7 @@ async def execute_search(
             index_param = ITEM_INDICES
             query = add_collections_to_body(collection_ids, query)
 
-        max_result_window = MAX_LIMIT
+        max_result_window = get_max_limit()
 
         size_limit = min(limit + 1, max_result_window)
 

stac_fastapi/opensearch/stac_fastapi/opensearch/database_logic.py

@@ -16,7 +16,7 @@
 
 from stac_fastapi.core.base_database_logic import BaseDatabaseLogic
 from stac_fastapi.core.serializers import CollectionSerializer, ItemSerializer
-from stac_fastapi.core.utilities import MAX_LIMIT, bbox2polygon
+from stac_fastapi.core.utilities import bbox2polygon, get_max_limit
 from stac_fastapi.extensions.core.transaction.request import (
     PartialCollection,
     PartialItem,
@@ -540,7 +540,7 @@ async def execute_search(
 
         search_body["sort"] = sort if sort else DEFAULT_SORT
 
-        max_result_window = MAX_LIMIT
+        max_result_window = get_max_limit()
 
         size_limit = min(limit + 1, max_result_window)
 

stac_fastapi/tests/api/test_api.py

@@ -1540,3 +1540,27 @@ async def test_collection_items_limit_env_variable(
     assert resp.status_code == 200
     resp_json = resp.json()
     assert int(limit) == len(resp_json["features"])
+
+
+@pytest.mark.asyncio
+async def test_search_max_item_limit(
+    app_client, load_test_data, txn_client, monkeypatch
+):
+    limit = "10"
+    monkeypatch.setenv("ENV_MAX_LIMIT", limit)
+
+    test_collection = load_test_data("test_collection.json")
+    await create_collection(txn_client, test_collection)
+
+    item = load_test_data("test_item.json")
+
+    for i in range(20):
+        test_item = item.copy()
+        test_item["id"] = f"test-item-collection-{i}"
+        await create_item(txn_client, test_item)
+
+    resp = await app_client.get("/search", params={"limit": 20})
+
+    assert resp.status_code == 200
+    resp_json = resp.json()
+    assert int(limit) == len(resp_json["features"])