A Snapshot Is Not a Rebuild: Five Myths About Free Dev Boxes

Описание и применение

Рабочий процесс позволяет выявлять и устранять разницу в окружениях бесплатных dev‑box’ов, используя скрипт manifest.sh для создания стабильного отпечатка, фильтрацию переменных полей и diff для обнаружения дрейфа.

Задача

Developers assume free or borrowed development boxes are identical, but subtle environmental differences cause test failures and drift.

Результат

The workflow produces a reproducible, version‑controlled representation of a dev environment, making drift visible and fixable, and discouraging reliance on unverified snapshots.

Рабочий процесс

• Run manifest.sh on a working box to emit a stable fingerprint.
• Provision a clean free box and replay the bootstrap.sh script.
• Run manifest.sh again on the clean box.
• Use strip_volatile to filter out fields that legitimately vary across hosts.
• Diff the normalized fingerprints; any differences indicate missing pins or unfiltered fields.
• Commit the diff alongside the bootstrap script fix as a bug report.
• Repeat the drill periodically based on project context (e.g., quarterly for pure‑Python services, every bump for native extensions).

Доказательства

Two instances built from the same image can still disagree about the C library, the locale, the timezone database, and the global package tree.

Источник

Run manifest.sh on the box that works, provision a clean free box, replay your bootstrap.sh, and run manifest.sh again there.

Источник

The diff is the entire deliverable: every line in it is either a fact your bootstrap forgot to pin or a field your filter should have dropped.

Источник