History

Joshua Rich 7759eba071 build(mage): ✨ rework mage build system to support native and cross-compilation - mage now supports setting TARGETARCH environment variable to specify cross-compilation - update build/test github action workflows for mage changes - update Dockerfile for mage changes - adjust codeql github action workflow to "autobuild"		2024-05-27 22:07:06 +10:00
..
README.md	build(mage): ✨ rework mage build system to support native and cross-compilation	2024-05-27 22:07:06 +10:00
agent.md	docs: 🐛 remove old method from interface example	2024-02-22 10:05:13 +10:00
sensors.md	docs: 📝 update developer agent docs	2024-02-22 10:03:41 +10:00

README.md

Go Hass Agent Development Notes

Build Requirements

Go Hass Agent uses Mage for development. Make sure you follow the instructions on the Mage website to install Mage. If you are using the devcontainer (see below), this is already installed.

Development Environment

It is recommended to use Visual Studio Code. This project makes use of a Devcontainer to provide some convenience during development.

If using Visual Studio Code, you should be prompted when opening your cloned copy of the code to set up the dev container. The container contains an installation of Home Assistant and Mosquitto (MQTT broker) that can be used for testing. They should be started automatically.

Home Assistant will be listening on http://localhost:8123.
Mosquitto will be listening on http://localhost:1833.

Note that while you can also build and run the agent within the container environment, this will limit what sensors are reported and may even hinder development of new sensors. As such, it is recommended to build and run outside the container. You can still connect to Home Assistant running within the container, as it is exposed as per above.

Building

Use the following mage invocation in the project root directory:

mage -d build/magefiles -w . build:full

This will:

Run go mod tidy.
Run go fmt ./....
Run go generate ./....
Build a binary and place it in dist/go-hass-agent-amd64.

To just build a binary, replace build:full with build:fast in the mage invocation above.

Packages

Go Hass Agent uses nfpm to create packages for Fedora, Arch, and Ubuntu and fyne-cross to create packages for Debian and Linux distributions with older libraries.

To build packages, use the following invocations:

mage -v -d build/magefiles -w . package:nfpm
mage -v -d build/magefiles -w . package:fyneCross

The above mage actions will install the necessary tooling for packaging, if needed.

Packages built with nfpm will be available under the dist/ folder. Packages built with fyne-cross will be available under fyne-cross/dist/linux-amd64/.

Other Architectures

Go Hass Agent can also be built for arm and arm64 with cross-compilation. This is only supported on Ubuntu as the host for cross-compiles. To build for a different architecture, set the TARGETARCH environment variable:

export TARGETARCH=arm # or arm64

Install the target architecture libraries for cross-compilation:

mage -d build/magefiles -w . preps:deps

Then the commands for building and packaging above should work as expected.

[!NOTE] The devcontainer has all the necessary compilers and libraries installed for cross-compilation.

Container Images

A Dockerfile that you can use to build an image can be found here.

You can build an image with a command like the following (using Podman):

podman build --file ./Dockerfile --network host --tag go-hass-agent

Committing Code

This repository is using conventional commit messages. This provides the ability to automatically include relevant notes in the changelog. The TL;DR is when writing commit messages, add a prefix:

feat: for a new feature, like a new sensor.
fix: when fixing an issue.
refactor: when making non-visible but useful code changes.
…and so on. See the link above or see the existing commit messages for examples.

Extending the Agent

Adding OS support

The intention of the agent design is to make it OS-agnostic.

Most OS specific code for fetching sensor data should likely be part of a GOARCH package and using filename suffixes such as filename_GOOS_GOARCH.go. See the files under linux/ as examples.

For some OSes, you might need some code to initialise or create some data source or API that the individual sensor fetching code uses. This code should be placed in device/, using filename suffixes such as filename_GOOS_GOARCH.go

For example, on Linux, a D-Bus connection is used for a lot of the sensor data gathering.

In such cases, you should pass this through as a value in a context. You can create the following function for your platform:

SetupContext(ctx context.Context) context.Context

It should accept a context.Context and derive its own context from this base that contains the necessary values for the platform. It will be propagated throughout the code wherever a context is passed and available for retrieval and use.

An example can be found in device/device_linux.go.