Helium Python Helper

A helper module used across various Nebra repos to reduce redundant features.

This package is used in a number of Nebra software repos:

• hm-pktfwd
• hm-config
• hm-diag
• hm-dashboard (private repo)
• Hotspot-Production-Tool (private repo)

The package is available on PyPI and PyPI test repos:

• PyPI hm-pyhelper
• PyPI Test hm-pyhelper

Helium Hardware Definitions

from hm_pyhelper.hardware_definitions import variant_definitions

This repository contains the python file that contains a GPIO map for all of the different hardware combinations to be supported by the Nebra Helium Hotspot Software.

All numbers below are their GPIO / BCM Numbers, not physical pin numbers.

Note: Light hotspot software will also work on all models listed as type "full".

Nebra Hotspots

Third Party Hotspots

We may be adding in support for other vendor's hotspots to use our software soon. Here are the variables for those.

These would also depend on their SOCs being supported by Balena.

DIY Hotspots

The following DIY options are also supported for light hotspot software only.

Please note, DIY Hotspots do not earn HNT.

hardware_definitions

variant_definitions

A dictionary of all known Nebra hotspot variants. Not all variants are fully supported.

get_variant_attribute(variant_name, variant_attribute)

Returns the value of an attribute from a specific variant. Raises UnknownVariantException and UnknownVariantAttributeException if invalid params supplied.

logger

from hm_pyhelper.logger import get_logger
LOGGER = get_logger(__name__)
LOGGER.debug("message to log")

miner_param

retry_get_region(region_override, region_filepath)

Return the region from envvar region_override or from the contents of region_filepath

from hm_pyhelper.miner_param import retry_get_region
print(retry_get_region("US915", "/invalid/path"))
# US915

# echo "EU868" > /var/pktfwd/region
print(retry_get_region("", "/var/pktfwd/region"))
# EU868

gateway-mfr-rs (gateway_mfr)

This helper module brings in the armv6 build of gateway-mfr-rs (gateway_mfr) which allows us to program the ECC secure element chips in production.

We have a GitHub action in this repo called update-gateway-mfr-rs.yml which checks the upstream repo for updated release versions every Sunday at midnight and if a new release is found it triggers a new PR in this repo to update the version number. This action also can be triggered on workflow_dispatch: meaning you can also manually trigger it from the actions tab.

LockSingleton

LockSingleton prevents the concurrent access to a resource across threads.

Methods

LockSingleton()

Creates a new LockSingleton object.

acquire(timeout = DEFAULT_TIMEOUT)

Waits until the resource is available. DEFAULT_TIMEOUT = 2 seconds

release()

Release the resource.

locked()

Check if there is an available resource.

Usage

lock = LockSingleton()

try:
    # try to acquire the resource or may raise an exception
    lock.acquire()

    # do some work
    print("Starting work...")
    sleep(5)
    print("Finished work!")

    # release the resource
    lock.release()
except ResourceBusyError:
    print("The resource is busy now.")

@lock_ecc decorator

@lock_ecc(timeout=DEFAULT_TIMEOUT, raise_resource_busy_exception=True):

This is the convenient decorator wrapping around the LockSingleton.

• timeout: timeout value. DEFAULT_TIMEOUT = 2 seconds.
• raise_resource_busy_exception: set True to raise exception in case of timeout or some error, otherwise just log the error msg

Usage

@lock_ecc()
def run_gateway_mfr():
    return subprocess.run(
        [gateway_mfr_path, "key", "0"],
        capture_output=True,
        check=True
    )

gateway_mfr_result = run_gateway_mfr()
log_stdout_stderr(gateway_mfr_result)

helium/miner RPC

Send RPC commands to the miner container.

create_add_gateway_txn

Return a blockchain_txn_add_gateway_v1_pb2 signed by the gateway and formatted the same way as the smartphone app expects.

Usage:

While using miner container, use json rpc client
client = MinerClient()
While using gateway-rs container, use grpc client
client = GatewayClient()
result = client.create_add_gateway_txn('owner_address', 'payer_address', 'gateway_address')

gateway_address is optional and will only be used to validate the returned payload if supplied.

Testing

To run tests:

poetry install --with dev
poetry run pytest --cov=hm_pyhelper --cov-fail-under=90

Referencing a branch for development

It is sometimes convenient to use recent changes in hm-pyhelper before an official release. To do so, first double check that you've added any relevant dependencies to the install_requires section of setup.py. Then add the following lines to the project's Dockerfile.

RUN pip3 install setuptools wheel
RUN pip3 install --target="$OUTPUTS_DIR" git+https://github.com/NebraLtd/hm-pyhelper@BRANCH_NAME

Releasing

To release, use the Github new release flow.

1. Create a new tag in format vX.Y.Z. You can use a previously tagged commit, but this is not necessary.
2. Make sure the tag you created matches the value in setup.py.
3. Select master as the target branch. If you do not select the master branch, the tag should be in format vX.Y.Z-rc.N.
4. Title: Release vX.Y.Z.
5. Body:

Note: you can create the release notes automatically by selecting the "Auto-generate release notes" option on the releases page.

## What's Changed
* Foo
* Bar

**Full Changelog**: https://github.com/NebraLtd/hm-pyhelper/compare/v0.0.A...v0.0.Z

Release strategy

The automated GitHub Actions in this repo do the following:

• all pushes / PRs, regardless of branch, trigger a build of the wheels and python package which are released as build artifacts (see below section)
• pushes to master with an updated version number in setup.py are pushed to Test PyPI as well as being uploaded as build artifacts (note that if the version number isn't properly updated and is a duplicate of a previous one then the push to Test PyPI will fail)
• any tagged releases on master branch (see releasing process above) are built and published to PyPI as well as being uploaded as build artifacts

Test release artifacts

Note that artifacts (wheels and source) are uploaded to the GitHub Actions artifacts even when the build fails or isn't pushed to PyPI/Test PyPI due to not being on the master branch.

For example, this failed build, has artifacts uploaded here.

These artifacts can be useful for testing releases without needing to bump version numbers.