Update custome Proxmox container templates

I like to use a custom debian container image, that has some tools installed and a non root user setup. I then dump and export the rootfs as container template.

To keep this template updated, I wrote this script.

This script works for all distribitions, you just have to update the variables:

#!/bin/bash

set -euo pipefail

TEMPLATE=998
IMAGE_NAME="debian-12-custom_amd64"
UPDATE_CMD="apt-get update && apt-get dist-upgrade -y && apt-get autoremove -y && apt-get clean -y && history -c"
CONTAINER_STORAGE="local-lvm"
BACKUP_STORAGE="local"
TEMPLATE_STORAGE="local"

get_path() {
    if [[ "${1}" == 'local' ]]; then
        echo "/var/lib/vz"
    else
        echo "/mnt/pve/${1}"
    fi
}

generate_vmid() {
    while true; do
        local vmid=$((RANDOM % 9901 + 100))  # Generate a random number between 100 and 10000
        if ! pvesh get /cluster/resources --output-format json | jq -e ".[] | select(.vmid == ${vmid})" > /dev/null; then
            echo "$vmid"
            return
        fi
    done
}

main() {
    local vmid
    vmid=$(generate_vmid)

    trap 'cleanup "${vmid}"' EXIT

    pct clone "${TEMPLATE}" "${vmid}" --full --hostname "update-ct-image" --storage "${CONTAINER_STORAGE}"
    pct start "${vmid}"

    until pct exec "${vmid}" -- bash -c 'ping -c1 1.1.1.1 &>/dev/null'; do
        echo "Waiting for container to come online..."
        sleep 1
    done

    pct exec "${vmid}" -- bash -c "${UPDATE_CMD}"
    pct stop "${vmid}"

    local backup_path="$(get_path ${BACKUP_STORAGE})"
    local template_path="$(get_path ${TEMPLATE_STORAGE})"

    vzdump "${vmid}" --compress zstd --mode stop --storage "${BACKUP_STORAGE}"
    mv "${backup_path}/dump/vzdump-lxc-${vmid}"*.tar.zst "${template_path}/template/cache/${IMAGE_NAME}.tar.zst"
    rm "${backup_path}/dump/vzdump-lxc-${vmid}"*.log
    pct destroy "${vmid}" --purge

    trap - EXIT
}

cleanup() {
    local vmid="${1}"
    local backup_path="$(get_path ${BACKUP_STORAGE})"

    if [[ -n "${vmid}" ]]; then
        rm -rf "${backup_path}/dump/vzdump-lxc-${vmid}"*
        pct destroy "${vmid}" --purge
    fi
}

main "$@"

mietzen/Update_Custome_Proxmox_Container_Templates.md

Update custome Proxmox container templates