lab

eink-dashboard

Generates a 480×800px greyscale PNG for an e-ink display, updated hourly via Google Cloud Run. The image is served from a public GCS bucket at an unguessable UUID path.

What it shows

Header — day of week + date in Czech, name day from svatkyapi.cz

Weather forecast — 4 time slots (data from met.no):

Ráno (07:00), Poledne (12:00), Odpoledne (15:00), Večer (19:00)
Each slot: weather icon, temperature, Czech description, precipitation %
Always shows the next occurrence — if 12:00 has passed, shows tomorrow’s

Birthdays — next 3 upcoming birthdays with date, age, and days until. Today’s birthday gets a special highlight. Data loaded from a secret gist (see below).

Lunch — today’s or next school day’s meal from Schildkröte, scraped after login.

Footer — sunrise, day length (with ±diff vs yesterday), sunset

Architecture

Cloud Scheduler (hourly)
  → Cloud Run Job
      fetches weather + name day APIs
      renders HTML → PNG via headless Chromium
      uploads to GCS
  → GCS bucket (public-read)
      ← e-ink device polls every hour

Local development

python -m venv .venv && source .venv/bin/activate
pip install -r requirements.txt
playwright install chromium
python main.py
# output: dashboard.png

Runs locally without any GCP credentials — saves dashboard.png to disk.

GCP deployment

Prerequisites (one-time, manual)

Create a GCP project and enable billing
gcloud auth login && gcloud config set project $PROJ

Enable APIs:

gcloud services enable run.googleapis.com cloudbuild.googleapis.com \
  cloudscheduler.googleapis.com storage.googleapis.com \
  containerregistry.googleapis.com --project=$PROJ

Authenticate Docker: gcloud auth configure-docker gcr.io

Configuration

Copy .env.example to .env and fill in your values:

PROJ=your-gcp-project-id
BUCKET_NAME=your-bucket-name
FEED_ID=your-uuid   # generate with: python3 -c "import uuid; print(uuid.uuid4())"

.env is gitignored and never committed.

Birthdays

Birthday data is stored in a secret GitHub Gist as birthdays.json (see birthdays.json.example for the format). Add the raw gist URL to .env:

BIRTHDAYS_GIST_URL=https://gist.githubusercontent.com/you/abc123/raw/birthdays.json

Use the versionless /raw/<filename> URL (no commit hash) so updates to the gist are picked up automatically. The script fetches the gist at startup; if the URL is absent, the birthday section is simply empty.

First deploy

./deploy.sh

Sets up the bucket, service account, IAM roles, builds + pushes the Docker image, deploys the Cloud Run Job, and creates the hourly Cloud Scheduler trigger.

Redeploy (after code changes)

./redeploy.sh

Rebuilds the image using local Docker layer cache (fast — only the code layer rebuilds), pushes, updates the job, and triggers a test run.

Dependencies

Package	Purpose
`requests`	API calls
`astral`	Sunrise/sunset calculation
`playwright`	Headless Chromium screenshot
`google-cloud-storage`	GCS upload