bc31472469
This patch adds a scylla_inject_error(), a context manager which tests
can use to temporarily enable some error injection while some test
code is running. It can be used to write tests that artificially
inject certain errors instead of trying to reach the elaborate (and
often requiring precise timing or high amounts of data) situation where
they occur naturally.
The error-injection API is Scylla-specific (it uses the Scylla REST API)
and does not work on "release"-mode builds (all other modes are supported),
so when Cassandra or release-mode build are being tested, the test which
uses scylla_inject_error() gets skipped.
Example usage:
```python
from rest_api import scylla_inject_error
with scylla_inject_error(cql, "injection_name", one_shot=True):
# do something here
...
```
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes #12264
(cherry picked from commit 6d2e146aa6)
Single-node functional tests for Scylla's CQL features.
These tests use the Python CQL library and the pytest frameworks. By using an actual CQL library for the tests, they can be run against any implementation of CQL - both Scylla and Cassandra. Most tests - except in rare cases - should pass on both, to ensure that Scylla is compatible with Cassandra in most features.
To run all tests against an already-running local installation of Scylla
or Cassandra on localhost, just run pytest. The "--host" and "--port"
can be used to give a different location for the running Scylla or Cassanra.
The "--ssl" option can be used to use an encrypted (TLSv1.2) connection.
More conveniently, we have two scripts - "run" and "run-cassandra" - which do all the work necessary to start Scylla or Cassandra (respectively), and run the tests on them. The Scylla or Cassandra process is run in a temporary directory which is automatically deleted when the test ends.
"run" automatically picks the most recently compiled version of Scylla in
build/*/scylla - but this choice of Scylla executable can be overridden with
the SCYLLA environment variable. "run-cassandra" defaults to running the
command cassandra from the user's path, but this can be overriden by setting
the CASSANDRA environment variable to the path of the cassandra script,
e.g., export CASSANDRA=$HOME/apache-cassandra-3.11.10/bin/cassandra.
A few of the tests also require the nodetool when running on Cassandra -
this tool is again expected to be in the user's path, or be overridden with
the NODETOOL environment variable. Nodetool is not needed to test
Scylla.
Additional options can be passed to "pytest" or to "run" / "run-cassandra" to control which tests to run:
- To run all tests in a single file, do
pytest test_table.py. - To run a single specific test, do
pytest test_table.py::test_create_table_unsupported_names. - To run the same test or tests 100 times, add the
--count=100option. This is faster than runningrun100 times, because Scylla is only run once, and also counts for you how many of the runs failed. Forpytestto support the--countoption, you need to install a pytest extension:pip install pytest-repeat
Additional useful pytest options, especially useful for debugging tests:
- -v: show the names of each individual test running instead of just dots.
- -s: show the full output of running tests (by default, pytest captures the test's output and only displays it if a test fails)