Add RHEL Bare Metal Recovery (ReaR) script for Generic Application AgentFeature/rhel bmr rear

rhel_bmr_rear/rhel_bmr_rear.md

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+# RHEL Bare Metal Recovery with ReaR and PPDM Generic Application Agent
+
+## Overview
+
+This script set enables **Bare Metal Recovery (BMR)** of Red Hat Enterprise Linux (RHEL) systems using [Relax-and-Recover (ReaR)](https://relax-and-recover.org/) integrated with the **Dell PowerProtect Data Manager (PPDM) Generic Application Agent**.
+
+The backup script dynamically configures ReaR to write its bootable ISO and backup archive directly to the PPDM-managed **BoostFS** target directory, enabling deduplication, policy-based retention, and centralized management via PPDM.
+
+---
+
+## Architecture
+
+```
+RHEL Host
+│
+├── ReaR
+│   ├── Bootable ISO  (rescue environment)
+│   └── backup.tar.gz (full system backup)
+│
+└── BoostFS Mount (DD_TARGET_ASSET_BASE_PATH)
+        └── Managed by PPDM Generic Application Agent
+                └── Data Protection Domain (DD)
+```
+
+---
+
+## Requirements
+
+| Component | Details |
+|---|---|
+| OS | RHEL 8.x / 9.x |
+| ReaR | 2.6 or later (`dnf install rear`) |
+| FUSE | Required for BoostFS (`dnf install fuse`) |
+| PPDM | 19.22 or later |
+| Agent Type | **PaaS** (required for Generic Application Agent) |
+| Privileges | Root |
+
+---
+
+## PPDM Configuration
+
+### Application Type
+The asset must be configured as **PaaS** type in PPDM.
+
+### Environment Variables (injected by PPDM)
+
+| Variable | Description |
+|---|---|
+| `DD_TARGET_ASSET_BASE_PATH` | BoostFS mount point (managed by PPDM — do not mount/unmount manually) |
+| `BACKUP_LEVEL` | Always treated as `FULL` for BMR |
+| `ASSET_USERNAME` | Asset credentials (if configured) |
+| `ASSET_PASSWORD` | Asset credentials (if configured) |
+
+> **Important:** PPDM mounts and unmounts BoostFS automatically. Do **not** call `boostfs mount/unmount` commands from within the script.
+
+---
+
+## Files
+
+| File | Description |
+|---|---|
+| `rhel_bmr_rear_backup.sh` | Main backup script — configures ReaR and runs `rear mkbackup` |
+| `rhel_bmr_rear.md` | This documentation |
+
+---
+
+## Backup Flow
+
+1. PPDM mounts BoostFS at `DD_TARGET_ASSET_BASE_PATH`
+2. Backup script runs as root
+3. Existing `/etc/rear/site.conf` is preserved (restored after backup)
+4. ReaR is dynamically configured to write output to `DD_TARGET_ASSET_BASE_PATH`
+5. `rear mkbackup` creates:
+   - `<hostname>.iso` — bootable rescue environment
+   - `backup.tar.gz` — full system backup archive
+6. PPDM unmounts BoostFS and deduplicates data to DD
+
+---
+
+## Restore Flow
+
+Bare metal recovery requires booting the target machine from the ReaR ISO:
+
+1. Restore the PPDM backup to a local or network-accessible path
+2. Boot the target machine from the ISO (iDRAC virtual media, USB, PXE, etc.)
+3. At the ReaR rescue menu, select **Recover \<hostname\>**
+4. ReaR will automatically locate `backup.tar.gz` and restore the system
+5. Reboot and verify
+
+---
+
+## ReaR Configuration Files (`local.conf`)
+
+### Configuration Loading Order
+
+ReaR loads configuration files in the following order:
+
+```
+/etc/rear/default.conf   ← ReaR built-in defaults (do not edit)
+       ↓
+/etc/rear/site.conf      ← Dynamically generated by this script (backed up and restored)
+       ↓
+/etc/rear/local.conf     ← Host-specific overrides (loaded last, overrides site.conf)
+```
+
+> **Important:** Because `local.conf` is loaded after `site.conf`, any conflicting settings in `local.conf` will override the values set by this script.
+
+---
+
+### Default `local.conf` (no changes required)
+
+The default `local.conf` shipped with ReaR has all lines commented out and requires no modification:
+
+```bash
+# Default is to create Relax-and-Recover rescue media as ISO image
+# OUTPUT=ISO
+# BACKUP=NETFS
+# BACKUP_URL=nfs://192.168.122.1/tmp
+# ...
+```
+
+---
+
+### If `local.conf` Has Been Customized
+
+If any of the following settings are **uncommented**, they will conflict with this script. Comment out or remove the affected lines before running the backup.
+
+| Setting | Reason for conflict |
+|---|---|
+| `BACKUP_URL` | Overrides the BoostFS target path set by this script |
+| `OUTPUT_URL` | Overrides the ISO output destination |
+| `OUTPUT` | May change the output format away from ISO |
+| `BACKUP` | May change the backup method away from NETFS |
+
+**Verification command:**
+
+```bash
+# Show all active (non-commented) settings in local.conf
+grep -v '^\s*#' /etc/rear/local.conf | grep -v '^\s*$'
+# Empty output means the default configuration is in place — no action needed
+```
+
+---
+
+## Optional Customization
+
+To exclude specific paths from the backup, set `EXCLUDE_BACKUP` before calling the script:
+
+```bash
+export EXCLUDE_BACKUP="/mnt/scratch /tmp/large_data"
+```
+
+---
+
+## Known Limitations
+
+- Incremental BMR is not supported; `BACKUP_LEVEL` is always treated as FULL.
+- ReaR ISO size can be large (typically 300–600 MB). Plan DD capacity accordingly.
+- For Azure Local / Hyper-V guest RHEL VMs, Arc-enabled VM restoration after BMR is subject to Microsoft Arc integration constraints (not PPDM-specific).
+
+---
+
+## Author
+
+- takashi.odagiri@dell.com
+- Tested with PPDM 19.22 on RHEL 9.3

rhel_bmr_rear/rhel_bmr_rear_backup.sh

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+#!/bin/bash
+# ==============================================================================
+# PPDM Generic Application Agent - RHEL Bare Metal Recovery (ReaR) Backup Script
+# ==============================================================================
+# Description : Creates a ReaR bootable ISO and system backup, storing output
+#               to the PPDM-managed BoostFS target directory.
+# Requirements: - ReaR (relax-and-recover) installed on the target host
+#               - FUSE installed (required for BoostFS)
+#               - PPDM Generic Application Agent (PaaS type) configured
+#               - Run as root
+# Tested PPDM : 19.22
+# Author      : <your@dell.com>
+# ==============================================================================
+
+set -euo pipefail
+
+# ------------------------------------------------------------------------------
+# PPDM Environment Variables (injected by PPDM agent)
+# ------------------------------------------------------------------------------
+# DD_TARGET_ASSET_BASE_PATH : BoostFS mount point managed by PPDM
+# BACKUP_LEVEL              : FULL (incremental not supported for BMR)
+# ASSET_USERNAME            : Asset credentials (if required)
+# ASSET_PASSWORD            : Asset credentials (if required)
+#
+# Note: Application Type must be set to "PaaS" in PPDM asset configuration.
+# ------------------------------------------------------------------------------
+
+REAR_CONFIG_DIR="/etc/rear"
+REAR_SITE_CONF="${REAR_CONFIG_DIR}/site.conf"
+REAR_SITE_CONF_BACKUP="${REAR_CONFIG_DIR}/site.conf.ppdm_backup"
+TIMESTAMP=$(date +"%Y%m%d_%H%M%S")
+LOGFILE="/var/log/ppdm_rear_backup_${TIMESTAMP}.log"
+
+# ==============================================================================
+# Functions
+# ==============================================================================
+
+log() {
+    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" | tee -a "${LOGFILE}"
+}
+
+error_exit() {
+    log "ERROR: $*"
+    restore_rear_config
+    exit 1
+}
+
+check_prerequisites() {
+    log "Checking prerequisites..."
+
+    # Root check
+    [[ $EUID -eq 0 ]] || error_exit "This script must be run as root."
+
+    # ReaR installed
+    command -v rear &>/dev/null || error_exit "ReaR is not installed. Install with: dnf install rear"
+
+    # PPDM target path
+    [[ -n "${DD_TARGET_ASSET_BASE_PATH:-}" ]] || \
+        error_exit "DD_TARGET_ASSET_BASE_PATH is not set. Ensure PPDM agent is configured correctly."
+
+    # Target path accessible
+    [[ -d "${DD_TARGET_ASSET_BASE_PATH}" ]] || \
+        error_exit "Target path '${DD_TARGET_ASSET_BASE_PATH}' does not exist or is not mounted."
+
+    # BACKUP_LEVEL check (BMR only supports FULL)
+    if [[ "${BACKUP_LEVEL:-FULL}" != "FULL" ]]; then
+        log "WARNING: BACKUP_LEVEL='${BACKUP_LEVEL}' is not supported for BMR. Proceeding as FULL."
+    fi
+
+    log "Prerequisites OK."
+}
+
+backup_rear_config() {
+    if [[ -f "${REAR_SITE_CONF}" ]]; then
+        log "Backing up existing ReaR site.conf..."
+        cp "${REAR_SITE_CONF}" "${REAR_SITE_CONF_BACKUP}"
+    fi
+}
+
+restore_rear_config() {
+    if [[ -f "${REAR_SITE_CONF_BACKUP}" ]]; then
+        log "Restoring original ReaR site.conf..."
+        mv "${REAR_SITE_CONF_BACKUP}" "${REAR_SITE_CONF}"
+    else
+        # No original existed — remove the one we created
+        [[ -f "${REAR_SITE_CONF}" ]] && rm -f "${REAR_SITE_CONF}"
+    fi
+}
+
+configure_rear() {
+    log "Configuring ReaR to target: ${DD_TARGET_ASSET_BASE_PATH}"
+
+    mkdir -p "${REAR_CONFIG_DIR}"
+
+    cat > "${REAR_SITE_CONF}" <<EOF
+# Auto-generated by PPDM Generic Application Agent
+# $(date)
+
+OUTPUT=ISO
+BACKUP=NETFS
+
+# PPDM BoostFS mount point
+BACKUP_URL="file://${DD_TARGET_ASSET_BASE_PATH}"
+OUTPUT_URL="file://${DD_TARGET_ASSET_BASE_PATH}"
+
+# Optional: exclude large/unnecessary paths from backup
+EXCLUDE_BACKUP=( ${EXCLUDE_BACKUP:-} )
+
+# Optional: set backup compression (default: gzip)
+BACKUP_PROG_COMPRESS_OPTIONS=( --gzip )
+BACKUP_PROG_COMPRESS_SUFFIX=".gz"
+EOF
+
+    log "ReaR site.conf written."
+}
+
+run_rear_backup() {
+    log "Starting ReaR backup (rear mkbackup)..."
+    rear -v mkbackup 2>&1 | tee -a "${LOGFILE}" || \
+        error_exit "ReaR backup failed. Check ${LOGFILE} for details."
+    log "ReaR backup completed successfully."
+}
+
+verify_output() {
+    log "Verifying output files in ${DD_TARGET_ASSET_BASE_PATH}..."
+
+    local hostname
+    hostname=$(hostname -s)
+
+    # ReaR typically writes: <hostname>.iso and backup.tar.gz
+    local iso_file
+    iso_file=$(find "${DD_TARGET_ASSET_BASE_PATH}" -name "${hostname}*.iso" -newer "${LOGFILE}" 2>/dev/null | head -1)
+
+    local backup_file
+    backup_file=$(find "${DD_TARGET_ASSET_BASE_PATH}" -name "backup.tar*" -newer "${LOGFILE}" 2>/dev/null | head -1)
+
+    if [[ -z "${iso_file}" ]]; then
+        log "WARNING: ISO file not found in target path. Verify ReaR output."
+    else
+        log "ISO  : ${iso_file} ($(du -sh "${iso_file}" | cut -f1))"
+    fi
+
+    if [[ -z "${backup_file}" ]]; then
+        log "WARNING: Backup archive not found in target path."
+    else
+        log "Backup archive: ${backup_file} ($(du -sh "${backup_file}" | cut -f1))"
+    fi
+}
+
+# ==============================================================================
+# Main
+# ==============================================================================
+
+log "======================================================"
+log " PPDM Generic App Agent - RHEL BMR (ReaR) Backup"
+log " Host     : $(hostname)"
+log " PPDM Target: ${DD_TARGET_ASSET_BASE_PATH:-NOT SET}"
+log " Backup Level: ${BACKUP_LEVEL:-FULL}"
+log "======================================================"
+
+check_prerequisites
+backup_rear_config
+configure_rear
+run_rear_backup
+verify_output
+restore_rear_config
+
+log "Backup script completed. Log: ${LOGFILE}"
+exit 0