fix: usage of net schema when the postgres role misses privileges

test/test_privileges.py

@@ -0,0 +1,92 @@
+import pytest
+from sqlalchemy import text
+
+def test_net_postgres_usage(sess):
+    """Check that the postgres role can use the net schema by default"""
+
+    role = sess.execute(text("select current_user;")).fetchone()
+
+    assert role[0] == "postgres"
+
+    # Create a request
+    (request_id,) = sess.execute(text(
+        """
+        select net.http_get(
+            'http://localhost:8080/anything'
+        );
+    """
+    )).fetchone()
+
+    # Commit so background worker can start
+    sess.commit()
+
+    # Confirm that the request was retrievable
+    response = sess.execute(
+        text(
+            """
+        select * from net._http_collect_response(:request_id, async:=false);
+    """
+        ),
+        {"request_id": request_id},
+    ).fetchone()
+    assert response[0] == "SUCCESS"
+
+def test_net_another_usage(sess):
+    """Check that another role can use the net schema when granted usage"""
+
+    sess.execute(text("""
+        set local role postgres;
+        create role another;
+        grant usage on schema net to another;
+    """))
+
+    # Create a request
+    (request_id,) = sess.execute(text(
+        """
+        set local role to another;
+        select net.http_get(
+            'http://localhost:8080/anything'
+        );
+    """
+    )).fetchone()
+
+    # Commit so background worker can start
+    sess.commit()
+
+    # Confirm that the request was retrievable
+    response = sess.execute(
+        text(
+            """
+        set local role to another;
+        select * from net._http_collect_response(:request_id, async:=false);
+    """
+        ),
+        {"request_id": request_id},
+    ).fetchone()
+    assert response[0] == "SUCCESS"
+
+    sess.execute(text("""
+        set local role postgres;
+        drop owned by another;
+        drop role another;
+    """))
+
+def test_net_fails_when_postgres_unprivileged(sess):
+    """If the postgres role is unprivileged (no superuser + no privileges), the request will fail. This can happen on cloud databases where postgres is no superuser and the initial pg_net postgres privileges are revoked (can happen when upgrading)."""
+
+    with pytest.raises(Exception) as execinfo:
+        sess.execute(text("""
+            set local role postgres;
+
+            -- assume postgres is no superuser and has lost explicit privileges
+            alter role postgres nosuperuser;
+            revoke all on all tables in schema net from postgres;
+
+            -- still, assume postgres has grant usage on the schema net
+            grant usage on schema net to postgres;
+
+            select net.http_get(
+                'http://localhost:8080/anything'
+            );
+        """)).fetchone()
+    assert "permission denied for table http_request_queue" in str(execinfo)