Bug: NatsContainer does not seem to work with JetStream

[jackburridge]

Describe the bug

NatsContainer does not seem to work with JetStream

To Reproduce

Run the example_basic.py in the nats module.

You will first have to update the file as it doesn't run correctly, line 20 should be:

port = nats_container.get_exposed_port(nats_container.client_port)

It then fails on:

stream = await js.add_stream(name="test-stream", subjects=["test.>"])

With the error

python example_basic.py 
Connected to NATS
Traceback (most recent call last):
  File "/home/jackburridge/Dev/nats/.venv/lib/python3.10/site-packages/nats/js/manager.py", line 477, in _api_request
    msg = await self._nc.request(req_subject, req, timeout=timeout)
  File "/home/jackburridge/Dev/nats/.venv/lib/python3.10/site-packages/nats/aio/client.py", line 1068, in request
    raise errors.NoRespondersError
nats.errors.NoRespondersError: nats: no responders available for request

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/jackburridge/Dev/nats/example_basic.py", line 152, in <module>
    asyncio.run(basic_example())
  File "/usr/lib/python3.10/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/usr/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
    return future.result()
  File "/home/jackburridge/Dev/nats/example_basic.py", line 31, in basic_example
    stream = await js.add_stream(name="test-stream", subjects=["test.>"])
  File "/home/jackburridge/Dev/nats/.venv/lib/python3.10/site-packages/nats/js/manager.py", line 118, in add_stream
    resp = await self._api_request(
  File "/home/jackburridge/Dev/nats/.venv/lib/python3.10/site-packages/nats/js/manager.py", line 480, in _api_request
    raise ServiceUnavailableError
nats.js.errors.ServiceUnavailableError: nats: ServiceUnavailableError: code=None err_code=None description='None'

Runtime environment

Operating system information:

uname -a
Linux pop-os 6.16.3-76061603-generic #202508231538~1761055796~22.04~ba79424 SMP PREEMPT_DYNAMIC Tue O x86_64 x86_64 x86_64 GNU/Linu

Python version

python --version
Python 3.10.12

Docker info:

docker info
Client: Docker Engine - Community
 Version:    28.5.1
 Context:    desktop-linux
 Debug Mode: false
 Plugins:
  ai: Docker AI Agent - Ask Gordon (Docker Inc.)
    Version:  v1.9.11
    Path:     /home/jackburridge/.docker/cli-plugins/docker-ai
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.29.1-desktop.1
    Path:     /home/jackburridge/.docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.40.3-desktop.1
    Path:     /home/jackburridge/.docker/cli-plugins/docker-compose
  debug: Get a shell into any image or container (Docker Inc.)
    Version:  0.0.45
    Path:     /home/jackburridge/.docker/cli-plugins/docker-debug
  desktop: Docker Desktop commands (Docker Inc.)
    Version:  v0.2.0
    Path:     /home/jackburridge/.docker/cli-plugins/docker-desktop
  extension: Manages Docker extensions (Docker Inc.)
    Version:  v0.2.31
    Path:     /home/jackburridge/.docker/cli-plugins/docker-extension
  init: Creates Docker-related starter files for your project (Docker Inc.)
    Version:  v1.4.0
    Path:     /home/jackburridge/.docker/cli-plugins/docker-init
  mcp: Docker MCP Plugin (Docker Inc.)
    Version:  v0.28.0
    Path:     /home/jackburridge/.docker/cli-plugins/docker-mcp
  offload: Docker Offload (Docker Inc.)
    Version:  v0.5.20
    Path:     /home/jackburridge/.docker/cli-plugins/docker-offload
  pass: Docker Pass Secrets Manager Plugin (beta) (Docker Inc.)
    Version:  v0.0.11
    Path:     /home/jackburridge/.docker/cli-plugins/docker-pass
  sandbox: Docker Sandbox (Docker Inc.)
    Version:  v0.6.0
    Path:     /home/jackburridge/.docker/cli-plugins/docker-sandbox
  sbom: View the packaged-based Software Bill Of Materials (SBOM) for an image (Anchore Inc.)
    Version:  0.6.0
    Path:     /home/jackburridge/.docker/cli-plugins/docker-sbom
  scout: Docker Scout (Docker Inc.)
    Version:  v1.18.3
    Path:     /home/jackburridge/.docker/cli-plugins/docker-scout

Server:
 Containers: 0
  Running: 0
  Paused: 0
  Stopped: 0
 Images: 22
 Server Version: 29.0.1
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 CDI spec directories:
  /etc/cdi
  /var/run/cdi
 Discovered Devices:
  cdi: docker.com/gpu=webgpu
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: fcd43222d6b07379a4be9786bda52438f0dd16a1
 runc version: v1.3.3-0-gd842d771
 init version: de40ad0
 Security Options:
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 6.12.54-linuxkit
 Operating System: Docker Desktop
 OSType: linux
 Architecture: x86_64
 CPUs: 8
 Total Memory: 3.662GiB
 Name: docker-desktop
 ID: 9d39b93b-1e69-4b12-b413-35c7c9175803
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 HTTP Proxy: http.docker.internal:3128
 HTTPS Proxy: http.docker.internal:3128
 No Proxy: hubproxy.docker.internal
 Labels:
  com.docker.desktop.address=unix:///home/jackburridge/.docker/desktop/docker-cli.sock
 Experimental: false
 Insecure Registries:
  hubproxy.docker.internal:5555
  ::1/128
  127.0.0.0/8
 Live Restore Enabled: false

Python packages:

pip freeze
certifi==2025.11.12
charset-normalizer==3.4.4
docker==7.1.0
idna==3.11
nats-py==2.12.0
python-dotenv==1.2.1
requests==2.32.5
testcontainers==4.13.3
typing_extensions==4.15.0
urllib3==2.5.0
wrapt==2.0.1