10Backward

Daily Mastodon throwback bot scaffolded with Docker Compose.

The container runs a cron daemon that invokes the Python entrypoint once per day at the configured RUN_AT (Europe/Berlin default). The actual blog clone / post pipeline is intentionally stubbed in this scaffold and is to be implemented in a follow-up job — this repository currently ships:

• Pinned Python dependency manifest.
• Dockerfile (python:3.11-slim + cron + git + ca-certificates + tzdata).
• docker-compose.yml building locally, mounting .env read-only and persisting ./data for the blog clone and posted.json state.
• entrypoint.sh that validates required env vars and fails clearly on startup before launching cron -f in the foreground.
• Safe .env.example with placeholder credentials only.

Build & run

cp .env.example .env       # fill in real credentials locally
docker compose build
docker compose up -d
docker compose logs -f bot

./data is persisted across restarts on the host. The blog clone (added in a follow-up job) will live in ./data/blog/, and posted-state in ./data/posted.json.

Configuration

Variable	Required	Default	Notes
MASTODON_BASE_URL	yes	—	e.g. https://mastodon.social
MASTODON_ACCESS_TOKEN	yes	—	never commit
SITE_URL	yes	—	source blog URL (HTTPS)
HASHTAGS	yes	—	comma-separated, e.g. #throwback,#10backward
RUN_AT	yes	09:00	HH:MM in TZ
MASTODON_VISIBILITY	no	public	public, unlisted, private, direct
THROWBACK_PREFIX	no	Throwback:	German-localizable
RETRY_COUNT	no	3	post retries
TZ	no	Europe/Berlin	any IANA timezone

Tests

pip install -r requirements-dev.txt
pytest