testcontainers / testcontainers/testcontainers-python
Question: Cannot start KafkaContainer() (on windows(?))
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Description
I am trying to create a KafkaContainer for my integration test, but I have issues starting it.
Using testcontainers==4.12.0, the following snippet has no issues:
from testcontainers.kafka import KafkaContainer
kafka_container = KafkaContainer()
kafka_container.start()
kafka_bootstrap_servers = cls.kafka_container.get_bootstrap_server()
However, upgrading to testcontainers==4.14.2, the same snippet gives the following issue:
Traceback (most recent call last):
File "...\test.py", line 42, in setUpClass
cls.kafka_container.start()
File "...\env\Lib\site-packages\testcontainers\kafka\__init__.py", line 192, in start
self.tc_start()
File "...\env\Lib\site-packages\testcontainers\kafka\__init__.py", line 165, in tc_start
port = self.get_exposed_port(self.port)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "...\env\Lib\site-packages\testcontainers\core\container.py", line 251, in get_exposed_port
return self._get_exposed_port(port)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "...\env\Lib\site-packages\testcontainers\core\container.py", line 257, in _get_exposed_port
return int(self.get_docker_client().port(c.id, port))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "...\env\Lib\site-packages\testcontainers\core\docker_client.py", line 170, in port
raise ConnectionError(f"Port mapping for container {container_id} and port {port} is not available")
ConnectionError: Port mapping for container 06001694f7ed34dac7f89c4f3a3488d23a884338ec2cc8b367120c2452d39382 and port 9093 is not available
I did a simple investigation and found out that the waiting logic has changed between these two tags. When I use tag 13.0 and 13.1, there is a "legacy deprecation warning" but KafkaContainer can still be started.
...\test.py:40: DeprecationWarning: The wait_for_logs function with string or callable predicates is deprecated and will be removed in a future version. Use structured wait strategies instead: container.waiting_for(LogMessageWaitStrategy('ready')) or container.waiting_for(LogMessageWaitStrategy(re.compile(r'pattern')))
wait_for_logs(cls.kafka_container, "started")
Specifically, the ConnectionError I mentioned above occurred when I upgraded 13.1 to 13.2. The changes I suspect could cause this would be this line
Not sure if this is caused by wrong usage of the library or my personal setup. It is worth noting that I have to disable Ryuk when running the code snippet (using TESTCONTAINERS_RYUK_DISABLED=true) and I am running the code snippet from Windows cmd.
Let me know if there are more information I could provide to investigate this further
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Research direction
Start with testcontainers/kafka/init.py and testcontainers/core/docker_client.py, focusing on the waiting and port-mapping changes between v4.13.1 and v4.13.2. Reproduce the supplied KafkaContainer snippet on Windows with Ryuk disabled, then verify that the container starts and get_bootstrap_server() returns a usable endpoint.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- docker, kafka, python
- Domain
- devops, testing-qa
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Quiet
- Clarity
- Mostly clear
- Newbie friendliness
- 48/100