Purpose

tenbackward.config.load_config() is the single boundary that turns process environment + optional .env file into a typed Config dataclass. Job 1083 changes every variable that ships in .env.example so that it is explicitly required at every layer (entrypoint.sh, config.validate_config, and the rendered cron).

Required Environment Variables

All eight of these must be present and non-empty in the process environment for the container to boot.

Key	Purpose	Validation
`MASTODON_BASE_URL`	Mastodon instance to post against.	Must parse with `http` or `https` scheme and a non-empty netloc.
`MASTODON_ACCESS_TOKEN`	OAuth token used by the future Mastodon.py client.	Required string.
`VISIBILITY`	Default post visibility.	Must be `public` or `unlisted`.
`SITE_URL`	Source blog URL (used by the future clone step).	Must parse with `http` or `https` scheme and a non-empty netloc.
`HASHTAGS`	Comma-separated hashtags appended to every throwback.	Required string (formatting handled by the future poster).
`THROWNBACK_PREFIX`	Per-post title prefix (default: `Throwback:`).	Required string.
`MAX_RETRIES`	Number of additional retries after the first attempt.	Non-negative integer (parsed by `_parse_max_retries`).
`RUN_AT`	Daily fire time for the cron entry.	`HH:MM` 24-hour format.
`TZ`	IANA timezone used by cron + the container clock.	Must resolve via `zoneinfo.ZoneInfo`.

Note

— All nine keys are required since Job 1083. The previously optional MASTODON_VISIBILITY, THROWBACK_PREFIX, and RETRY_COUNT were promoted to first-class citizens and renamed to VISIBILITY, THROWNBACK_PREFIX, and MAX_RETRIES.

Defaults

DEFAULTS in config.py provides fallback strings that apply_defaults fills into the merged map before validation runs:

Default key	Default value
`VISIBILITY`	`public`
`THROWNBACK_PREFIX`	`Throwback:`
`MAX_RETRIES`	`3`
`TZ`	`Europe/Berlin`
`RUN_AT`	`09:00`

Because every required key carries a default, a freshly-initialised container can still boot to validate the scaffold, but the operator must supply MASTODON_BASE_URL and MASTODON_ACCESS_TOKEN (and ideally SITE_URL) to make a real run.

`Config` Dataclass

Field	Type	Source
`mastodon_base_url`	`str`	`MASTODON_BASE_URL`
`mastodon_access_token`	`str`	`MASTODON_ACCESS_TOKEN`
`visibility`	`str`	`VISIBILITY`
`site_url`	`str`	`SITE_URL`
`hashtags`	`str`	`HASHTAGS`
`throwback_prefix`	`str`	`THROWNBACK_PREFIX`
`max_retries`	`int`	`MAX_RETRIES` (parsed as non-negative int)
`run_at`	`str`	`RUN_AT`
`tz`	`str`	`TZ`
`data_dir`	`Path`	Constant: `Path("/app/data")`

Validation Behaviour

validate_config(values) collects all failures before raising so the operator sees every problem at once. A single ConfigError lists each problem joined with "; ". Validation covers:

Required keys are non-empty.
RUN_AT parses as HH:MM.
MASTODON_BASE_URL and SITE_URL parse via urllib.parse.urlparse with an http/https scheme and a non-empty netloc.
VISIBILITY is one of {"public", "unlisted"} (ALLOWED_VISIBILITY).
TZ resolves via zoneinfo.ZoneInfo.
MAX_RETRIES parses as a non-negative integer (rejects bools).

Exit Codes

Code	Source	Meaning
`1`	`main.main()` (retry budget exhausted)	Pipeline failed on every attempt after `MAX_RETRIES + 1` tries.
`2`	`main.main()` (`ConfigError`)	Configuration was present but invalid; details are logged.

Citations

[1] src/tenbackward/config.py — REQUIRED_KEYS, DEFAULTS, ALLOWED_VISIBILITY, Config, load_config, validate_config.
[2] .env.example — canonical env-var list.
[3] entrypoint.sh — shell-side mirror of the required keys.

5.8 KiB Raw Blame History