refactor(store)!: remove ObjectStore.signed_post

src/agent_env/store/object_store/gcs_object_store.py

@@ -289,25 +289,18 @@ def issue_upload_policy(
             expires_at=expires_at,
         )
 
-    def signed_post(
-        self, url_prefix: str, *, expires_in: int = 3600, max_bytes: int | None = None
-    ) -> dict | None:
-        if not self._can_sign():
-            return None
-        return self._post_policy(url_prefix, min(expires_in, self._max_signed_seconds), max_bytes)
-
-    def _post_policy(self, url_prefix: str, expires_in: int, max_bytes: int | None) -> dict:
+    def _post_policy(self, url_prefix: str, expires_in: int, max_bytes: int) -> dict:
         """Built by hand: the client library's helper adds an exact-key condition, which would
         confine the policy to one object. The prefix ends in ``/``, so that ``root`` does not
         admit ``root-evil/``."""
         bucket, prefix = _split(url_prefix.rstrip("/") + "/")
         now = datetime.now(UTC).replace(microsecond=0)
         timestamp = now.strftime("%Y%m%dT%H%M%SZ")
         credential = f"{self._signer.signer_email}/{now:%Y%m%d}/auto/storage/goog4_request"
-        conditions: list = [["starts-with", "$key", prefix], ["starts-with", "$Content-Type", ""]]
-        if max_bytes is not None:
-            conditions.append(["content-length-range", 0, max_bytes])
-        conditions += [
+        conditions: list = [
+            ["starts-with", "$key", prefix],
+            ["starts-with", "$Content-Type", ""],
+            ["content-length-range", 0, max_bytes],
             {"bucket": bucket},
             {"x-goog-date": timestamp},
             {"x-goog-credential": credential},

src/agent_env/store/object_store/object_store.py

@@ -164,20 +164,6 @@ def signed_put_url(self, object_url: str, expires_in: int = 3600) -> str | None:
         or None if the backend can't produce one (e.g. local filesystem)."""
         return None
 
-    def signed_post(
-        self, url_prefix: str, *, expires_in: int = 3600, max_bytes: int | None = None
-    ) -> dict | None:
-        """Credentials letting a remote party upload objects it names itself, anywhere
-        under ``url_prefix``. None if the backend can't produce them.
-
-        Prefix-scoped so the uploader owns its file layout — the caller bounds where
-        it may write, not what it may call things. That is also why the grant is a
-        dict and not a url: a signed url covers one key, since the key is part of
-        what is signed, so a prefix needs a policy the uploader submits as form
-        fields. Pass the whole value on, not just ``url``.
-        """
-        return None
-
     def shared_credentials_env(self) -> dict[str, str]:
         """Environment variables handing credentials to the agents and env services agent-env
         deploys, so they can use this store directly. None by default; a deployment that wants

src/agent_env/store/object_store/s3_object_store.py

@@ -226,19 +226,12 @@ def issue_upload_policy(
             expires_at=datetime.now(UTC) + timedelta(seconds=expires_in),
         )
 
-    def signed_post(
-        self, url_prefix: str, *, expires_in: int = 3600, max_bytes: int | None = None
-    ) -> dict | None:
-        return self._post_policy(url_prefix, expires_in, max_bytes)
-
-    def _post_policy(self, url_prefix: str, expires_in: int, max_bytes: int | None) -> dict:
+    def _post_policy(self, url_prefix: str, expires_in: int, max_bytes: int) -> dict:
         """A presigned POST for any key below ``url_prefix``: the key is a condition the uploader
         fills in, not part of what is signed. The prefix ends in ``/``, so that ``root`` does not
         admit ``root-evil/``."""
         bucket, prefix = self._split(url_prefix.rstrip("/") + "/")
-        conditions: list = [["starts-with", "$key", prefix]]
-        if max_bytes is not None:
-            conditions.append(["content-length-range", 0, max_bytes])
+        conditions: list = [["starts-with", "$key", prefix], ["content-length-range", 0, max_bytes]]
         # POST policies are default-deny on extra form fields: without this the
         # uploader's Content-Type 403s and objects store as binary/octet-stream.
         conditions.append(["starts-with", "$Content-Type", ""])

src/agent_env/store/routing.py

@@ -552,9 +552,6 @@ def signed_get_url(self, object_url: str, expires_in: int = 3600) -> str | None:
     def signed_put_url(self, object_url: str, expires_in: int = 3600) -> str | None:
         return self._writing(object_url).signed_put_url(object_url, expires_in)
 
-    def signed_post(self, url_prefix: str, *, expires_in: int = 3600, max_bytes: int | None = None) -> dict | None:
-        return self._writing(url_prefix).signed_post(url_prefix, expires_in=expires_in, max_bytes=max_bytes)
-
     def shared_credentials_env(self) -> dict[str, str]:
         """None: an ``@local`` run's objects reach its sandboxes through grants, staging or pushed bytes, so the
         configured store's credentials, the caller's own, stay with the caller."""

tst/unit/store/gcs_object_store_test.py

@@ -511,24 +511,12 @@ def test_an_upload_policy_lasts_at_most_what_its_signer_can_sign(store, client):
 def test_without_a_signer_there_is_no_upload_policy(unsigned):
     with pytest.raises(GrantUnavailableError, match="no signer"):
         unsigned.issue_upload_policy(f"gs://{BUCKET}/ns/", max_object_bytes=8, expires_in=600)
-    assert unsigned.signed_post(f"gs://{BUCKET}/ns/") is None
-
-
-def test_signed_post_is_shaped_as_the_s3_store_s_and_clamped_to_the_signer(store, client):
-    post = store.signed_post(f"gs://{BUCKET}/snap/", expires_in=10**7)
-    assert set(post) == {"url", "fields"} and post["fields"]["key"] == "snap/${filename}"
-    document = _policy(post["fields"])
-    assert _expiration(document) <= datetime.now(UTC) + timedelta(seconds=43200)
-    assert not any(isinstance(c, list) and c[0] == "content-length-range" for c in document["conditions"])
-    slashless = _policy(store.signed_post(f"gs://{BUCKET}/snap")["fields"])
-    assert ["starts-with", "$key", "snap/"] in slashless["conditions"]
-    root = store.signed_post(f"gs://{BUCKET}/")["fields"]
-    assert root["key"] == "${filename}" and ["starts-with", "$key", ""] in _policy(root)["conditions"]
-    bounded = _policy(store.signed_post(f"gs://{BUCKET}/snap/", max_bytes=5)["fields"])
-    assert ["content-length-range", 0, 5] in bounded["conditions"]
-    keyed = GcsObjectStore(client, BUCKET, signer=_key_credentials())
-    expiration = _expiration(_policy(keyed.signed_post(f"gs://{BUCKET}/snap/", expires_in=10**7)["fields"]))
-    assert datetime.now(UTC) + timedelta(seconds=43200) < expiration <= datetime.now(UTC) + timedelta(seconds=604800)
+
+
+def test_an_upload_policy_at_the_bucket_root_admits_every_key(store, signer):
+    write = store.issue_upload_policy(f"gs://{BUCKET}/", max_object_bytes=8, expires_in=600).write
+    assert write.fields["key"] == "${filename}"
+    assert ["starts-with", "$key", ""] in _policy(write.fields)["conditions"]
 
 
 def test_changelog_capture_gets_the_object_form(store):

tst/unit/task/local_run_write_fence_test.py

@@ -36,7 +36,7 @@
 LOCAL_TASK = "@local/~/bundle/tasks/t"
 LOCAL_ENV = "@local/~/bundle/envs/tickets"
 _DOCUMENT_WRITES = ("insert", "update", "update_one_and_get", "replace", "delete")
-_OBJECT_WRITES = ("put", "put_file", "put_file_at", "signed_put_url", "signed_post", "issue_write_grant", "issue_upload_policy")
+_OBJECT_WRITES = ("put", "put_file", "put_file_at", "signed_put_url", "issue_write_grant", "issue_upload_policy")
 
 
 def _refusing(cls, methods):