python-can-hub 0.2.6

python-can backend for can-hub: remote CAN interfaces over unix/tcp/tls/quic

python-can-hub

Native python-can backend for can-hub: consume remote CAN interfaces exported by can-hub agents, directly over the binary protocol — unix socket, plain TCP, TLS or QUIC, with mTLS identity and TOFU pinning on the encrypted transports. No bridge process in between.

import can

bus = can.Bus(
    interface="canhub",
    channel="truck42/can0",
    url="quic://hub.example.com:7227",
)
bus.send(can.Message(arbitration_id=0x123, data=b"\xDE\xAD\xBE\xEF"))
for message in bus:
    print(message)

• channel: namespaced interface agent/iface (or the numeric id from can-hub-client list).
• url: omit to connect to the local hub unix socket.
• state_dir: client TLS identity + pin store location (tls/quic).
• receive_own_messages: standard python-can echo semantics.
• reliable: carry the channel on a dedicated reliable QUIC stream (lossless, ordered) instead of the lossy datagram plane. Needs a quic:// url and a hub that advertises the capability; otherwise the open fails.

Write access follows the hub client ACLs: if the ACL grants read-only, the bus opens read-only and send() raises.

Listing interfaces

CanHubBus.list_interfaces() asks a hub for the interfaces it exports. Each entry is a python-can config dict you can splat straight into can.Bus:

from canhub import CanHubBus
import can

for config in CanHubBus.list_interfaces(url="quic://hub.example.com:7227"):
    print(config["channel"])          # e.g. "can-agent/can0"
bus = can.Bus(**CanHubBus.list_interfaces()[0])   # first interface, local hub

It accepts the same connection arguments as the bus (url, identity_cert, identity_key, hub_fingerprint, state_dir); omit url to query the local hub unix socket.

This also wires python-can's discovery: can.detect_available_configs("canhub") returns the same dicts. With no explicit target it reads the connection from the environment — CANHUB_URL, CANHUB_STATE_DIR, CANHUB_IDENTITY_CERT, CANHUB_IDENTITY_KEY, CANHUB_HUB_FINGERPRINT — falling back to the local hub unix socket. So CANHUB_URL=quic://hub.example.com:7227 points discovery at a remote host without any code.

The wheel bundles libcanhub.so with the TLS/QUIC stack linked in statically; the only runtime dependency is glibc.

Testing

The unit tests stub the native library, so they run without a build:

pip install -e python/.[test]
pytest python/tests

The backend is also exercised end-to-end against real binaries (recv, send, list_interfaces, and can.detect_available_configs discovery) by test/e2e/tests/python_can.robot; run the whole bench with make e2e.

Building from source

./scripts/build-python-wheel.sh        # host arch, glibc-tagged (local dev)
pip install python/dist/*.whl

Distributable manylinux wheels are built per architecture in a manylinux container and repaired by auditwheel (needs docker, plus QEMU binfmt for the cross arches):

./scripts/build-python-wheel.sh x86_64   # python/dist/x86_64/*.whl
./scripts/build-python-wheel.sh aarch64
./scripts/build-python-wheel.sh armv7l

The release workflow builds these three on native runners (aarch64/armv7l on the arm64 hosted runner, no QEMU) plus a cross-compiled win_amd64 wheel, and publishes all four to PyPI on a v* tag.