bin-there-done-that/miscellaneous/bash/documentation/venv-backup-script.md

# 🐍 Python Virtual Environment Backup Script

This Bash script automates the process of backing up Python virtual environments. It performs the following steps:

1. Locates virtual environments in a specified root directory
2. Archives them into a compressed `.tar.gz` file
3. Transfers the backup to a remote server using `rsync`
4. Deletes local backups older than a specified retention period

---

## 📦 Features

- Detects virtual environments by checking for `bin/activate`
- Compresses selected environments into a tarball
- Transfers the backup to a remote server via SSH
- Deletes backups older than a retention threshold
- Uses strict error handling to avoid silent failures

---

## ⚙️ Configuration

| Variable         | Description                                                             |
|------------------|-------------------------------------------------------------------------|
| `VENV_ROOT`      | Directory where virtual environments are stored                         |
| `BACKUP_DIR`     | Local directory where the backup tarballs are saved                     |
| `RETENTION_DAYS` | Number of days to retain local backups                                  |
| `REMOTE_USER`    | SSH user for the remote backup server                                   |
| `REMOTE_HOST`    | Hostname or IP address of the remote server                             |
| `REMOTE_PATH`    | Remote directory where backups will be copied via `rsync`               |

---

## 📝 Script Walkthrough

### 1. Setup

```bash
#!/usr/bin/env bash
set -euo pipefail
```

- Enables strict error handling to prevent unnoticed failures.

---

### 2. Define Variables

```bash
VENV_ROOT="/home/doc"
BACKUP_DIR="$VENV_ROOT/backups"
RETENTION_DAYS=7

REMOTE_USER="root"
REMOTE_HOST="thevault.bounceme.net"
REMOTE_PATH="/mnt/backup3/pythonvenvs"
```

---

### 3. Generate Timestamped Backup Filename

```bash
DATE=$(date +'%F_%H-%M-%S')
BACKUP_FILE="$BACKUP_DIR/venvs_backup_$DATE.tar.gz"
```

---

### 4. Ensure Backup Directory Exists

```bash
mkdir -p "$BACKUP_DIR"
```

---

### 5. Locate Virtual Environments

```bash
mapfile -t VENV_DIRS < <(
  find "$VENV_ROOT" -maxdepth 1 -type d \
    -exec test -f "{}/bin/activate" \; -print
)
```

If no environments are found, the script exits:

```bash
if [ ${#VENV_DIRS[@]} -eq 0 ]; then
  echo "❌ No virtual environments found under $VENV_ROOT"
  exit 1
fi
```

---

### 6. Extract Environment Names and Archive

```bash
VENV_NAMES=()
for path in "${VENV_DIRS[@]}"; do
  VENV_NAMES+=( "$(basename "$path")" )
done

echo "🔄 Backing up virtual environments: ${VENV_NAMES[*]}"
tar czf "$BACKUP_FILE" -C "$VENV_ROOT" "${VENV_NAMES[@]}"
echo "✅ Local backup saved to $BACKUP_FILE"
```

---

### 7. Sync Backup to Remote Server

```bash
echo "📡 Sending backup to ${REMOTE_USER}@${REMOTE_HOST}:${REMOTE_PATH}/"
rsync -az --progress "$BACKUP_FILE" \
      "${REMOTE_USER}@${REMOTE_HOST}:${REMOTE_PATH}/"
```

Check if sync was successful:

```bash
if [ $? -ne 0 ]; then
  echo "❌ Remote sync failed!"
  exit 1
else
  echo "✅ Remote sync succeeded."
fi
```

---

### 8. Cleanup Old Backups

```bash
echo "🗑️ Removing local backups older than $RETENTION_DAYS days..."
find "$BACKUP_DIR" -type f -name "venvs_backup_*.tar.gz" \
     -mtime +$RETENTION_DAYS -delete
echo "🎉 Backup and cleanup complete."
```

---

## 🧪 Example Output

```text
🔄 Backing up virtual environments: venv1 venv2
✅ Local backup saved to /home/doc/backups/venvs_backup_2025-05-01_02-00-00.tar.gz
📡 Sending backup to root@thevault.bounceme.net:/mnt/backup3/pythonvenvs/
✅ Remote sync succeeded.
🗑️ Removing local backups older than 7 days...
🎉 Backup and cleanup complete.
```

---

## 🛡️ Notes

- Ensure SSH access is set up for passwordless login to the remote host.
- Confirm that `rsync` is installed on both the local and remote systems.
- Consider running this script via `cron` or `systemd` for automation.

---

## 🖋️ Author

Maintained by **Doc**. Custom backup tooling for Genesis Hosting infrastructure.