Add a helper to fetch scylla_transport_cql_errors_total{type="protocol_error"} counter
from Scylla's metrics endpoint. These metrics are used to track protocol error
count before and after each test.
Add cql_with_protocol context manager utility for session creation with parameterized
protocol_version value. This is used for testing connection establishment with
different protocol versions, and proper disposal of successfully established sessions.
The tests cover two failure scenarios:
- Protocol version mismatch in test_protocol_version_mismatch which tests both supported
and unsupported protocol version
- Malformed frames via raw socket in _protocol_error_impl, used by several test functions,
and also test_no_protocol_exceptions test to assert that the error counters never decrease
during test execution, catching unintended metric resets
Refs: #24567
Python and Python developers don't like directory names to include a
minus sign, like "cql-pytest". In this patch we rename test/cql-pytest
to test/cqlpy, and also change a few references in other code (e.g., code
that used test/cql-pytest/run.py) and also references to this test suite
in documentation and comments.
Arguably, the word "test" was always redundant in test/cql-pytest, and
I want to leave the "py" in test/cqlpy to emphasize that it's Python-based
tests, contrasting with test/cql which are CQL-request-only approval
tests.
Fixes#20846
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
