Project «mhz19-go»

This project is a backend for the home automation server, written on Golang. Evolution of another myne project mhz19-next which was a typescript-based.

Real use cases

• Switch smart ceiling light on/off upon receiving message from smart wall switch
• Automatically switch storage room light upon receiving message from movement sensor
• Automatically switch storage room ventilation, when movement sensor reports a human presense and room door sensor reports it is closed
• Play alert sound, notify owner via telegram and cut off home water supply upon receiving message from one of water leakage sensors
• Notify owner then some guarded door (equipped with smart sensor) was opened/closed and user is not at home

See full list of configured rules: user rules and system rules

Project goal

• Create pure offline, vendor agnostic and fully controlled local home automation server
• Bring project to modern stack and learn golang while project migration from typescript

Applied best practices

• Source code organisation folows SOLID/clean-architecture recommendations
• DI to enable better UTs coverage
• Folders layout in accordance with project-layout
• With unit tests, race tests and code coverage stats enabled
• Sql schema and basic data migrations support
• Load tests for the REST API
• Race tests
• Collecting prometheus metrics, configured prometheus and dashboard in grafana
• Makefile for the common developer tasks and docker-compose file to deploy app with additional tooling (prometheus, grafana)
• Backlog with TODOs

Architecture

• Channel providers which collect messages from different channels and devices into unified stream. Supported channels are mqtt, telegram, dns-sd, sonoff (TBD) and yeelight (TBD).
• History storage which persist received messages in sqlite db
• Versatile mapping rules Engine which defines how application should respond to received messages
• Actions executor which executes one or more actions in respond to received message
• REST API layer to manage application: create rules, read device messages history, read registered devices
• Telegram as a channel to delivery various notifications and alerts and remote controll
• Docker compose to deploy entire server, which consists of this backend, frontend (TBD), device-pinger service, eclipse mosquitto as mqtt message broker, zigbee2mqtt zigbee bridge, metrics database prometheus and grafana for metrics visualization.

Unified message structure

No matter which channel was used to receive a message, or which certain device has emitted that message, we pack every message into unified strusture to be handled by Engine.

• Channel type - mqtt, telegram, dns-sd, sonoff, yeelight
• Device class - zigbee device, zigbee bridge, device-pinger, valves-manipulator, telegram-bot, sonoff diy-plug device, yeelight device
• Device id - unique device identifier, specific for the certain device class. e.g. zigbee ieee device address 0x00158d0004244bda or device IP
• Payload - the message itself as a json. untyped, specific for the certain device and channel. e.g. zigbee wall switch message may look like {"battery":100,"action":"single_left"} or telegram-bot message as {"Text":"/open-valves"}
• Timestamp - a time when message was received by the server, usefull when reading and visualizing historical data

Used technologies

• golang as main app language
• sqlite3 with go-sqlite3 client as a persistent storage
• ozzo-routing http routing
• godotenv and go-envconfig as configuration layer
• eclipse paho as mqtt client
• docker for containerization
• Makefile for developer routine automation
• telegram bot api with client for the notifications and remote management
• dnssd as mdns client (sonoff smart devices discovery)
• gabs as json querier

Screenshots

Dashboard Console

Migrations, schema version validation

• make migrate-reset - execute all down migrations and then all up migrations, basically reset schema to its default empty state
• make migrate-down - execute all down migrations
• make migrate-up - execute all up migrations
• make migrate-up-single - run certain migration up
• make migrate-down-single - run certain migration down
• make migrate-dump - create current schema dump

Load tests

• make api-load-rules-read
• make api-load-rules-write
• make api-load-push-message-write

Starting development instance

• create db and run all migrations make migrate-up or reset to inital state with make migrate-reset
• create config file from sample cp .env.sample .env
• optionally: run tests with make test
• run application make run

Deploying production instance

• create db and run all migrations make migrate-up
• create config file from sample cp .env.sample .env
• build image with make docker-build
• create and run container make docker-up
• optionally: check logs with make docker-logs

Initial data seeding (provisioning)

DIR=devices make seed DIR=rules/system make seed DIR=rules/user make seed

Tools required for the development on the bare host

• go wget https://go.dev/dl/go1.23.0.linux-amd64.tar.gz, rm -rf /usr/local/go && tar -C /usr/local -xzf go1.23.0.linux-amd64.tar.gz, export PATH=$PATH:/usr/local/go/bin
• golangci-lint https://golangci-lint.run/welcome/install curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.60.3
• gcc sudo apt install gcc
• delve go install -v github.com/go-delve/delve/cmd/dlv@latest
• sqlite3 sudo apt-get install sqlite3
• oha brew install oha

Usefull commands

run and view logs for selected module only make run 2>&1 >/dev/null | grep "engine" scp log scp ivanf@192.168.88.188:/home/ivanf/Projects/mhz19-go/log.txt ~/Desktop htop hotkeys: - t - toggle tree view - Shift + k - toglle showing kernel processes - p - toggle showing full paths

measure on/off time for sonoff relay https://stackoverflow.com/questions/18215389/how-do-i-measure-request-and-response-times-at-once-using-curl curl -w "@assets/curl-format.txt" -v -d '{"data":{"switch":"off"}}' http://192.168.88.60:8081/zeroconf/switch

Profiling

• run cpu and memory benchmark for single unit test and save two profiles accordingly make bench
• open cpu profile in pprof make pprof-cpu
• open memory profile in pprof make pprof-mem
• inside pprof: see top N records top
• inside pprof: open top N graph in browser web
• inside pprof: see memory allocation for certain function list Test31
• collect 10s cpu profile from running app curl --location 'http://localhost:7070/debug/pprof/profile?seconds=10' > back_cpu.prof
• collect 10s head allocations profile from running app curl --location 'http://localhost:7070/debug/pprof/heap?seconds=10' > back_heap.prof
• open heap snapshot in text format in browser http://localhost:7070/debug/pprof/heap?debug=1
• open local cpu profile in pprof web version go tool pprof -http=:7272 back_cpu.prof
• open remote heap profile in local pprof web version go tool pprof -http=:7272 http://192.168.88.188:7070/debug/pprof/heap
• open remote cpu profile in local pprof web version go tool pprof -http=:7272 http://192.168.88.188:7070/debug/pprof/profile
• list of available profilers http://localhost:7070/debug/pprof

Database schema

• rules - TBD
• rule_conditions - TBD
• rule_actions - TBD
• rule_condition_or_action_arguments - TBD
• rule_action_argument_mappings - TBD
• condition_functions - TBD
• action_functions - TBD
• device_classes - TBD
• channel_types - TBD
• devices - TBD
• messages - TBD
• schema_version - since v1, TBD