s3-lifecycle-delta 0.1.0

A Python library to manage S3 lifecycle policies and track changes in Delta format.

s3-lifecycle-delta

A small Python library to compute and apply deltas on AWS S3 lifecycle policies—especially focused on safe, declarative storage class transitions—with dry-run, validation, and minimal disruption.

Problem

AWS S3 lifecycle policies are typically applied by overwriting the entire configuration. That makes automated changes brittle, error-prone, and risky when you only want to tweak transitions (e.g., change from STANDARD → GLACIER after 90 days) without accidentally deleting other rules.

This library:

• Introspects the current lifecycle policy
• Compares it to the desired policy (the "delta")
• Shows what would change (dry-run)
• Validates rules
• Applies only the intended change safely

Features

• Declarative lifecycle policy definitions (via Python / JSON)
• Diff engine: detects rule adds / updates / deletes
• Safe apply with dry-run
• Validation of transition semantics (e.g., non-decreasing days)
• Idempotent behavior
• Pluggable for custom validation or rule logic

Quickstart

Install (editable for dev)

git clone https://github.com/your-org/s3-lifecycle-delta.git
cd s3-lifecycle-delta
pip install -e .