Check SSD mounting with HOOK

[torre94]

I'd like to use a second internal SSD plus as repository.
The SSD is mounted by the host and then by Docker, but I'd like to verify that it's properly mounted before running a snapshot.
Is it possible to do this by HOOK?
From the host it's something like if mount /mnt/second-ssd but I'm not sure how to do it from the container or if I should consider a different approach.

[garethgeorge]

Hey -- what you're looking at should be something you can do with a hook, but the backrest docker package may not be easy to setup correctly for what you're trying to do.

Managing mounts typically works best with a baremetal install that can access host devices, etc.

[torre94]

Right! It would be very simple if I weren't using Docker.
However, I've noticed that Restic can't launch a snapshot if the repository isn't valid, for example, after a USB drive has been disconnected. I will try to understand if this "protection" is sufficient.

A possible alternative could be a hook like this?

restic -r /repos/usb-drive snapshots > /dev/null 2>&1
if [ $? -eq 0 ]; then
    exit 0
fi

[garethgeorge]

E.g. as a way of checking if the repo is available and otherwise cancelling the backup?

https://garethgeorge.github.io/backrest/cookbooks/command-hook-examples shows a few examples of preflight hooks with similar checks and ON_ERROR_CANCEL conditions if I'm understanding what you're looking for rightly

[torre94]

Thanks for the suggestions.
After some experimentation, I opted for a bare-metal installation as root.
It seems the best method if your main repository is on a local drive.

This makes easier to check that if drive is mounted. In addition, you can check the repository existence with restic snapshots.
Checking only the directory existance may be weak, and restic check takes some time for large repos.

This is my pre-backup hook script:

#!/bin/bash

DRIVE_PATH="/mnt/second-ssd"
REPO_PATH="$DRIVE_PATH/backup-restic"
RESTIC_BINARY="/root/.local/share/backrest/restic"

if ! mountpoint -q "$DRIVE_PATH"; then
  echo "Drive not mounted."
  exit 1
fi

if ! $RESTIC_BINARY snapshots --repo "$REPO_PATH" > /dev/null; then
    echo "Invalid or non-existent repository."
    exit 1
fi