Add query-param fallback to analytics ignore check

.env.example

@@ -12,6 +12,10 @@ ANALYTICS_ENABLED=false
 # logged, just never recorded. Both empty disables the check.
 ANALYTICS_IGNORE_HEADER=
 ANALYTICS_IGNORE_VALUES=
+# Same check on a query string param instead of a header, for plain <a href>
+# download links that cannot set a header at all. Matched against
+# ANALYTICS_IGNORE_VALUES above. Empty disables this check.
+ANALYTICS_IGNORE_QUERY_PARAM=
 # Fallback for callers that cannot yet set the header above: a request from
 # one of these source IPs (comma-separated) skips analytics the same way.
 # Weaker signal - an IP can change without this list being updated. Empty

datastore/analytics.py

@@ -16,7 +16,9 @@
     the versioned action namespace and ``<base>/dump/*``; probes, docs and the
     welcome page are excluded by definition. A request carrying the
     configured ignore header/value (``ANALYTICS_IGNORE_HEADER`` /
-    ``ANALYTICS_IGNORE_VALUES``), or arriving from a configured ignore IP
+    ``ANALYTICS_IGNORE_VALUES``), the same value on a configured query
+    param (``ANALYTICS_IGNORE_QUERY_PARAM`` - for plain ``<a href>`` links
+    that cannot set a header), or arriving from a configured ignore IP
     (``ANALYTICS_IGNORE_IPS``, a weaker fallback for callers that cannot yet
     set the header), is skipped entirely - not logged with a distinguishing
     field, just never recorded.
@@ -110,6 +112,7 @@ def __init__(
         service: str = "datastore-api",
         ignore_header: str = "",
         ignore_values: frozenset[str] = frozenset(),
+        ignore_query_param: str = "",
         ignore_ips: frozenset[str] = frozenset(),
     ) -> None:
         self.app = app
@@ -122,6 +125,11 @@ def __init__(
         #: ``ANALYTICS_IGNORE_VALUES``; either empty disables the check.
         self.ignore_header = ignore_header.lower()
         self.ignore_values = ignore_values
+        #: Same check, but on a query string param instead of a header - for
+        #: plain `<a href>` download links, which cannot set a header at
+        #: all. Matched against the same ``ignore_values``. Configured via
+        #: ``ANALYTICS_IGNORE_QUERY_PARAM``; empty disables the check.
+        self.ignore_query_param = ignore_query_param
         #: A request whose resolved ``request_ip`` is in ``ignore_ips`` skips
         #: analytics the same way - a fallback for callers that cannot yet
         #: set the ignore header (e.g. the DXP frontend's static egress IPs).
@@ -136,6 +144,12 @@ def _is_ignored(self, scope: Scope, headers: Headers) -> bool:
             value = headers.get(self.ignore_header)
             if value is not None and value.strip().lower() in self.ignore_values:
                 return True
+        if self.ignore_query_param and self.ignore_values:
+            query: bytes = scope.get("query_string", b"")
+            params = parse_qs(query.decode("latin-1"))
+            values = params.get(self.ignore_query_param) or []
+            if any(v.strip().lower() in self.ignore_values for v in values):
+                return True
         if self.ignore_ips:
             if self._request_ip(scope, headers) in self.ignore_ips:
                 return True

datastore/core/config.py

@@ -79,9 +79,10 @@ class Config(BaseSettings):
     ANALYTICS_IGNORE_VALUES: str = Field(
         default="",
         description=(
-            "Comma-separated header values that skip analytics logging "
-            "when ANALYTICS_IGNORE_HEADER matches (e.g. `data-explorer`). "
-            "Matched case-insensitively. Empty disables the check."
+            "Comma-separated values that skip analytics logging when "
+            "ANALYTICS_IGNORE_HEADER or ANALYTICS_IGNORE_QUERY_PARAM "
+            "matches (e.g. `data-explorer`). Matched case-insensitively. "
+            "Empty disables both checks."
         ),
     )
 
@@ -92,6 +93,16 @@ def analytics_ignore_values_set(self) -> frozenset[str]:
             v.strip().lower() for v in self.ANALYTICS_IGNORE_VALUES.split(",") if v.strip()
         )
 
+    ANALYTICS_IGNORE_QUERY_PARAM: str = Field(
+        default="",
+        description=(
+            "Query string param name checked the same way as "
+            "ANALYTICS_IGNORE_HEADER, for plain `<a href>` download links "
+            "that cannot set a header (e.g. `request_source`). Matched "
+            "against ANALYTICS_IGNORE_VALUES. Empty disables the check."
+        ),
+    )
+
     ANALYTICS_IGNORE_IPS: str = Field(
         default="",
         description=(

datastore/main.py

@@ -111,6 +111,7 @@ def create_app() -> FastAPI:
             service="Datastore",
             ignore_header=config.ANALYTICS_IGNORE_HEADER,
             ignore_values=config.analytics_ignore_values_set,
+            ignore_query_param=config.ANALYTICS_IGNORE_QUERY_PARAM,
             ignore_ips=config.analytics_ignore_ips_set,
         )
     # Added last = outermost, so 4xx/5xx envelopes carry CORS headers too.

tests/test_analytics.py

@@ -227,10 +227,12 @@ def _client_with_ignore_config(
     *,
     header: str = "",
     values: str = "",
+    query_param: str = "",
     ips: str = "",
 ) -> TestClient:
     monkeypatch.setenv("ANALYTICS_IGNORE_HEADER", header)
     monkeypatch.setenv("ANALYTICS_IGNORE_VALUES", values)
+    monkeypatch.setenv("ANALYTICS_IGNORE_QUERY_PARAM", query_param)
     monkeypatch.setenv("ANALYTICS_IGNORE_IPS", ips)
     get_config.cache_clear()
 
@@ -383,6 +385,60 @@ def test_the_header_and_ip_checks_are_independent(
     assert recorded == []
 
 
+def test_a_dump_link_with_the_ignore_query_param_is_not_recorded(
+    fake_ckan: FakeCKAN,
+    cache: InMemoryCache,
+    recorded: list[dict],
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """The real use case: a plain <a href> download link can't set a
+    header, so the same value rides in the query string instead."""
+    c = _client_with_ignore_config(
+        monkeypatch,
+        fake_ckan,
+        cache,
+        query_param="request_source",
+        values="admin-portal",
+    )
+    url = "https://storage.googleapis.com/bucket/dumps/x/abc.csv?Sig=abc"
+
+    async def fake_dump(self: BigQueryBackend, resource_id: str, fmt: str) -> list[str]:
+        return [url]
+
+    with c, patch.object(BigQueryBackend, "dump", fake_dump):
+        response = c.get(
+            f"{DUMP_PREFIX}/{RESOURCE}?request_source=admin-portal",
+            follow_redirects=False,
+        )
+
+    assert response.status_code == 302
+    assert recorded == []
+
+
+def test_a_dump_link_without_the_ignore_query_param_is_still_recorded(
+    fake_ckan: FakeCKAN,
+    cache: InMemoryCache,
+    recorded: list[dict],
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    c = _client_with_ignore_config(
+        monkeypatch,
+        fake_ckan,
+        cache,
+        query_param="request_source",
+        values="admin-portal",
+    )
+    url = "https://storage.googleapis.com/bucket/dumps/x/abc.csv?Sig=abc"
+
+    async def fake_dump(self: BigQueryBackend, resource_id: str, fmt: str) -> list[str]:
+        return [url]
+
+    with c, patch.object(BigQueryBackend, "dump", fake_dump):
+        c.get(f"{DUMP_PREFIX}/{RESOURCE}", follow_redirects=False)
+
+    assert len(recorded) == 1
+
+
 def test_the_ignore_check_is_disabled_when_unconfigured(
     client: TestClient, recorded: list[dict]
 ) -> None: