Initial commit of various cheatsheets

removing-files-from-git-history.md

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+# Removing Files from Git History
+
+This document outlines a secure, resource-efficient method to completely remove a file (and its traces) from a Git repository's history using `git-filter-repo`. This is useful for privacy-sensitive operations, such as removing accidentally committed secrets or sensitive data.
+
+## Prerequisites
+- Git installed.
+- `git-filter-repo` installed (install via `sudo apt install git-filter-repo` on Debian-based systems if needed).
+- Admin access to the repository and remote (e.g., Gitea).
+
+## Steps
+1. **Verify the File in History**:
+   ```
+   cd /path/to/repo
+   git log -- <file-path>
+   ```
+   This lists commits involving the file.
+
+2. **Remove the File from History**:
+   ```
+   git filter-repo --path <file-path> --invert-paths
+   ```
+   - `--invert-paths` excludes the specified path from all commits.
+   - This rewrites history and removes remotes as a safety measure.
+
+3. **Re-add Remote (if removed)**:
+   ```
+   git remote add origin <remote-url>
+   ```
+
+4. **Force Push Changes**:
+   ```
+   git push origin --force --all
+   ```
+   - Use `--force` to overwrite remote history. Caution: This can break shared repos.
+
+5. **Verify Removal**:
+   ```
+   git log -- <file-path>
+   ```
+   No output means the file is gone.
+
+## Security Notes
+- Always back up your repo before rewriting history.
+- Use secure remotes (e.g., SSH).
+- Avoid if the repo is public or has multiple collaborators without coordination.
+- Follow least privilege: Run without sudo unless necessary.
+
+This method is lightweight and respects resource constraints (low RAM/CPU usage).
+
+Last updated: [Current Date]