Weeknotes 194

One of my car tyres has a slow puncture.

“LiveView feels faster with a delayed loading indicator”

In less than 5 minutes I made the change and deployed my app. I now have a LiveView page that feels so much more responsive! Let’s look at how to add this to an existing app.

Always interesting how small UX tweaks can affect the perceived performance even if nothing has actually gotten faster.

My foray into home automation continued with setting up the software side of things. It took a few hours, and some head scratching, but I seem to have the basics going – Docker is the way.

The basics in this case consists of zigbee2mqtt, Mosquitto, and Home Assistant.

Mosquitto is an MQTT broker, which implements the MQTT pub/sub protocol, and is used to publish and listen for messages. It sits between zigbee2mqtt and Home Assistant.

zigbee2mqtt is a replacement for proprietary hardware bridges and it talks to the various devices on the Zigbee network.

I’m using the SMLIGHT SLZB-06M over PoE as discussed last week, and watching Techno Tim’s “Creating a ZigBee Hub with the SMLIGHT SLZB-06 and Home Assistant” sent me in the right direction. My docker-compose.yml config now looks like this:

homeassistant:
  container_name: homeassistant
  image: "ghcr.io/home-assistant/home-assistant:stable"
  volumes:
    - /opt/appdata/homeassistant:/config
    - /etc/localtime:/etc/localtime:ro
    - /run/dbus:/run/dbus:ro
  restart: unless-stopped
  privileged: true
  network_mode: host

mqtt:
  container_name: mqtt
  image: eclipse-mosquitto:2.0
  restart: unless-stopped
  volumes:
    - /opt/appdata/mosquitto:/mosquitto
    - /etc/localtime:/etc/localtime:ro
    - /etc/timezone:/etc/timezone:ro
  ports:
    - 1883:1883
    - 9001:9001
  command: 'mosquitto -c /mosquitto-no-auth.conf'

zigbee2mqtt:
  container_name: zigbee2mqtt
  image: koenkk/zigbee2mqtt
  restart: unless-stopped
  volumes:
    - /opt/appdata/zigbee2mqtt:/app/data
    - ./zigbee2mqtt/configuration.yaml:/app/data/configuration.yaml:rw
    - /run/udev:/run/udev:ro
  ports:
    - 8080:8080
  environment:
    - /etc/localtime:/etc/localtime:ro
    - /etc/timezone:/etc/timezone:ro

zigbee2mqtt requires it’s own config too, which was the hardest part to figure out. One of the hardest parts of setting up weirdo hardware you bought online is identifying exactly what the thing is. For example, what chipset does it use? Even for models in the same product line, the chips are likely to be different, which is the case here.

The pertinent parts of my zigbee2mqtt config:

version: 4
permit_join: false
mqtt:
  base_topic: zigbee2mqtt
  server: mqtt://mqtt
serial:
  port: tcp://192.168.0.220:6638
  adapter: ezsp
advanced:
  channel: 11
frontend
  enabled: true
homeassistant:
  enabled: true

I had already purchased an array of temperature sensors, buttons, plug sockets, etc at a variety of price points. Unsurprisingly perhaps, the more expensive devices were easier to handle, generally looked nicer, and look to be better made. Saying that, I was surprised that even the cheapest devices seemed to pair and work relatively easily.

A promising start so far, but time will tell how reliable everything is. For now I’m just letting everything run and trialling how it holds up. Actual automations can come later.

“Siren Call of SQLite on the Server”. To balance all my pro-SQLite posts, here is the case against using SQLite for your web app.

“ok/1 & noreply/1 LiveView helpers!”

A nice tip for removing awkward return tuples from LiveViews.

During my Home Automation tinkering I learned about mDNS. The basics are that if your device and network supports mDNS you should be able to automatically refer to your device by <name>.local instead of it’s IP address or having to rely on separate DNS.

This did not work for me though.

As my “network” only really consists of a Virgin Broadband Hub I suspect that it lacks whatever is required to make it work.

Useful to know though.

A tip. Like any right thinking person, I want to keep my Docker config in git. That part is easy, create a repo, put your docker-compose.yml in it, and away you go. But what about other config files? zigbee2mqtt requires a configuration.yaml file. I want to version control it too, but in order to do so it has to live in the repo. So how do you supply it to the container so zigbee2mqtt can read and write it?

This is the git repo structure I would like. We can then add new directories as we add services keeping everything nicely organised.

.
├── docker-compose.yml
└── zigbee2mqtt
    └── configuration.yaml

My first thought, symlink it. This works, but when you setup the containers on a new host you’re going to have to remember to run the requisite ln -s steps. That is another thing to remember, and another thing to document.

Instead we can use some Docker magic.

On the server I already provide a place for containers to put their data under /opt/appdata/<service>.

  zigbee2mqtt:
    volumes:
      - /opt/appdata/zigbee2mqtt:/app/data

zigbee2mqtt can read and write to /app/data inside the running container and the files are put in /opt/appdata/zigbee2mqtt/ on the host system.

The magic comes when we bind mount the config file from the local git repo directly into the existing container volume.

  zigbee2mqtt:
    volumes:
      - /opt/appdata/zigbee2mqtt:/app/data
+     - ./zigbee2mqtt/configuration.yaml:/app/data/configuration.yaml:rw

(That :rw part at the end gives read/write permissions).

Now everything can stay in the git repo ✅

I very much enjoyed Bong Joon Ho’s Mickey 17. Recommended.