proxmox-grapple 2.0.2

The grappling hook for Proxmox backups.

Proxmox-grapple

The Python app that "hooks" into Proxmox.

This is a clone of vzdump-hook-script.pl that is written in Python, and that offers a lot more configurability.

Different phases of the vzdump backup can be hooked into, and things can be run.

The app also logs script output in realtime -- useful when using a long-running process (like rclone for example), and you want to see progressive timestamping against its output.

⚠️ NOTE! Version 2.0.0 introduces a breaking change to the config file format! See below.

Table of contents

• Proxmox-grapple
  • Table of contents
  • Purpose and uses
    • Running binaries
    • Running things via a shell
  • Installation
  • Configuration
    • Overview
    • Location
    • Configuration dump
    • Configuration environments
    • Breaking change in 2.0.0
      • Before 2.0.0 format
      • New format
  • Supported versions

Purpose and uses

Running binaries

Having hooks into each part of vzdump backups is very useful, especially to detect failures (or success) of the different backup phases.

For example, it can be used in concert with Healthchecks.io, Mailrise/Apprise, or other apps, to receive status notifications:

production:
  job-start:
    mode: script
    run:
      - "curl -fsS -m 10 --retry 5 -o /dev/null https://your.healthchecks.server/ping/xxx/vzdump-backups/start"
  job-abort:
    mode: script
    run:
      - "curl -fsS -m 10 --retry 5 -o /dev/null https://your.healthchecks.server/ping/xxx/vzdump-backups/fail"
  backup-abort:
    mode: script
    run:
      - "curl -fsS -m 10 --retry 5 -o /dev/null https://your.healthchecks.server/ping/xxx/vzdump-backups/fail"

Maybe you'd like to offsite-sync your backups on job completion:

  job-end:
    mode: script
    run:
      - "ssh some.host rclone sync --checkers 32 --transfers 16 --dscp cs1 --stats-log-level NOTICE --stats-unit=bits --stats=2m /mnt/pbs-backups remote.host:pbs-rsync"
      - "curl -fsS -m 10 --retry 5 -o /dev/null https://your.healthchecks.server/ping/xxx/vzdump-backups"

Or maybe as @lloydbayley uses it, via curl:

It actually changes the RGB lights in my rack when a backup happens so it's purely decorative but I like to automate things.

Anything that can be run on the CLI, you can use here.

Running things via a shell

Instead of using mode: script, you can use mode: shell, and anything configured will be run through a shell. This is directly equivalent to the shell argument to Python's subprocess.Popen.

What's the benefit here? To quote the Python documentation:

If shell is True, the specified command will be executed through the shell. This can be useful if you are using Python primarily for the enhanced control flow it offers over most system shells and still want convenient access to other shell features such as shell pipes, filename wildcards, environment variable expansion, and expansion of ~ to a user’s home directory.

The shell used is /bin/sh.

⚠️ WARNING! Read Python's Security Considerations section before using shell!

Environment

proxmox-grapple will expose the vzdump parameters to the following environment variables:

• GRAPPLE_PHASE
• GRAPPLE_MODE
• GRAPPLE_VMID

And all arguments in one:

• GRAPPLE_ALL_ARGS

These can then be used in your config as you see fit. Note you'll need to use shell mode, or use binaries that can read/expand/interpolate environment variables for you.

An example:

GRAPPLE_PHASE=backup-start
GRAPPLE_MODE=stop
GRAPPLE_VMID=102
GRAPPLE_ALL_ARGS=backup-start stop 102

Installation

The recommended way to install proxmox-grapple is to use pipx.

After getting pipx installed, simply run:

username@proxmox:~$ pipx install proxmox-grapple

Please don't use pip system-wide.

You can of course also install it using classic virtualenvs.

Once installed, you need to tell Proxmox (specifically vzdump) to use the app. Edit /etc/vzdump.conf and add or edit the script setting:

script: /home/username/.local/bin/proxmox-grapple

No other changes to the file is needed.

Configuration

Overview

proxmox-grapple is configured with a YAML-style file. An example:

production:
  job-end:
    mode: script
    run:
      - echo 'hi'
      - sleep 1
      - echo 'there'
      - echo 'This is a test.'

  backup-end:
    mode: script
    run:
    extract:
      enabled: false
      source_directory: /tmp
      destination_directory: /tmp
  #    exclude_storeids:

  job-abort:
    mode: shell
    run:
      - echo 'your strange command' | tee some_logfile.txt

Each top-level key should match the different vzdump phases. The currently recognised phases are:

• job-init
• job-start
• job-end
• job-abort
• backup-start
• backup-end
• backup-abort
• log-end
• pre-stop
• pre-restart
• post-restart

All of these are optional, and if not configured, are ignored.

If they are configured, the accompanying sub-keys are required:

• mode
• run

⚠️ The extract argument is currently not tested, and should be treated as a proof-of-concept only.

Location

The default location for the configuration is /etc/proxmox_grapple.yml, or proxmox_grapple.yml in the current working directory, but this can also be specified on the commandline.

If a non-absolute path is given, Dynaconf will iterate upwards: it will look at each parent up to the root of the system. For each visited folder, it will also try looking inside a /config folder.

Configuration dump

There is a mode, --dump-config, that reads all possible configuration and then prints it out for validation purposes.

Configuration environments

It can also use different configuration settings based on arbitrary environment names (eg. production, lab, etc.) It uses the Dynaconf Python project for configuration, so using environment variables to choose the environment and any other configuration option is possible.

⚠️ The default environment is production

For example, to choose a different configuration environment, set the environment variable ENV_FOR_DYNACONF=lab:

root@proxmox:~# ENV_FOR_DYNACONF=lab proxmox-grapple --dump-config

Breaking change in 2.0.0

To enable the use of the two run modes, I've decided to change the schema of the config file that needs to be updated.

Before 2.0.0 format

production:
  backup-start:
    script:
      - echo hi

New format

production:
  backup-start:
    mode: script
    run:
      - echo hi

Supported versions

proxmox-grapple supports the following VE versions:

VE version	Debian version	Python version	VE EoL
8	12 (Bookworm)	3.11	TBA
7	11 (Bullseye)	3.9	2024-07