copyLabelsToDisk.sh

#!/bin/bash

# this script copies iterates the VMs of a GCP project and copies 
# the labels of a machine to the disks attached to it
# you can pass a filter (the same as in gcloud command line)
# eg: to exclude some machines with fufu in the name 'name!~.*fufu.*'

if [ $# -eq 0 ]
  then
    echo "Need to supply project ID"
    exit 1
fi
project=$1

filter=""
if [ $# -eq 2 ]
  then
    echo "Filtering with $2"
    filter=" --filter=$2 "
fi

# get VMs and Zones
vmszones=$(gcloud compute instances list --project "${project}" --format="csv[no-heading](name,zone)" ${filter})
# vmszones=$(cat list)  # to debug

for entry in $vmszones; do
    IFS=','
    read -r vm zone <<< "${entry}"
    labelsSource=$(gcloud compute instances describe --project "${project}" --zone ${zone} ${vm} --format="csv[no-heading](labels,disks.source)")
    read -r labels disks <<< "${labelsSource}"
    echo "VM: ${vm} Zone: ${zone} labels: ${labels/;/,}"
    IFS=';'
    read -a diskA <<< "${disks}"

    for disk in ${diskA[@]}; do 
        echo "${disk##*/}"  # to get the name, we strip the last part of the full URL source
        gcloud compute disks add-labels "${disk##*/}" --project "${project}" --labels=${labels/;/,} --zone=${zone}
    done;

done;