4c2e026e04
As the test test_streams_closed_read confirmed, when a stream shard is closed, GetRecords should not return a NextShardIterator at all. Before this patch we wrongly returned an empty string for it. Before this patch, several Alternator Stream tests (in test_streams.py) failed when running against a multi-node Scylla cluster. The reason is as follows: As a multi-node cluster boots and more and more nodes enter the cluster, the cluster changes its mind about the token ownership, and therefore the list of stream shards changes. By the time we have the full cluster, a bunch of shards were created and closed without any data yet. All the tests will see these closed shards, and need to understand them. The fetch_more() utility function correctly assumed that a closed shard does not return a NextShardIterator, and got confused by the empty string we used to return. Now that closed shards can return responses without NextShardIterator, we also needed to fix in this patch a couple of tests which wrongly assumed this can't happen. These tests did not fail on DynamoDB because unlike in Scylla, DynamoDB does not have any closed shards in normal tests which do not specifically cause them (only test_streams_closed_read). We also need to fix test_streams_closed_read to get rid of an unnecessary assumption: It currently assumes that when we read the very last item in a closed shard is read, the end-of-shard is immediately signaled (i.e., NextShardIterator is not returned). Although DynamoDB does in fact do this, it is also perfectly legal for Alternator's implementation to return the last item with a new NextShardIterator - and only when the client reads from that iterator, we finally return the signal the end of the shard. Fixes #7237. Signed-off-by: Nadav Har'El <nyh@scylladb.com> Message-Id: <20200922082529.511199-1-nyh@scylladb.com>
Tests for Alternator that should also pass, identically, against DynamoDB.
Tests use the boto3 library for AWS API, and the pytest frameworks (both are available from Linux distributions, or with "pip install").
To run all tests against the local installation of Alternator on
http://localhost:8000, just run pytest.
Some additional pytest options:
- 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. - 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)
Add the --aws option to test against AWS instead of the local installation.
For example - pytest --aws test_item.py or pytest --aws.
If you plan to run tests against AWS and not just a local Scylla installation, the files ~/.aws/credentials should be configured with your AWS key:
[default]
aws_access_key_id = XXXXXXXXXXXXXXXXXXXX
aws_secret_access_key = xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
and ~/.aws/config with the default region to use in the test:
[default]
region = us-east-1
HTTPS support
In order to run tests with HTTPS, run pytest with --https parameter. Note that the Scylla cluster needs to be provided
with alternator_https_port configuration option in order to initialize a HTTPS server.
Moreover, running an instance of a HTTPS server requires a certificate. Here's how to easily generate
a key and a self-signed certificate, which is sufficient to run --https tests:
openssl genrsa 2048 > scylla.key
openssl req -new -x509 -nodes -sha256 -days 365 -key scylla.key -out scylla.crt
If this pair is put into conf/ directory, it will be enough
to allow the alternator HTTPS server to think it's been authorized and properly certified.
Still, boto3 library issues warnings that the certificate used for communication is self-signed,
and thus should not be trusted. For the sake of running local tests this warning is explicitly ignored.
Authorization
By default, boto3 prepares a properly signed Authorization header with every request. In order to confirm the authorization, the server recomputes the signature by using user credentials (user-provided username + a secret key known by the server), and then checks if it matches the signature from the header. Early alternator code did not verify signatures at all, which is also allowed by the protocol. A partial implementation of the authorization verification can be allowed by providing a Scylla configuration parameter:
alternator_enforce_authorization: true
The implementation is currently coupled with Scylla's system_auth.roles table,
which means that an additional step needs to be performed when setting up Scylla
as the test environment. Tests will use the following credentials:
Username: alternator
Secret key: secret_pass
With CQLSH, it can be achieved by executing this snipped:
cqlsh -x "INSERT INTO system_auth.roles (role, salted_hash) VALUES ('alternator', 'secret_pass')"
Most tests expect the authorization to succeed, so they will pass even with alternator_enforce_authorization
turned off. However, test cases from test_authorization.py may require this option to be turned on,
so it's advised.