ssh_key_to_cloud.sh

#!/bin/bash

# gist to add/modify your ssh key to the google cloud project
# run bash <(curl -s URL_TO_THIS_RAW_GIST) -p PROJECT

TEMP_KEYS="/tmp/ssh-keys"

jq_not_installed () {
    printf "\nplease install 'jq' util:\nbrew install jq\n\n" && exit 1
}

while [[ $# -gt 0 ]]
do
key="$1"

case $key in
    -p|--project)
    PROJECT="$2"
    shift 
    shift
    ;;
    -k|--key)
    SSH_KEY_PARAM="$2"
    shift
    shift
    ;;
    -u|--user)
    USER_PARAM="$2"
    shift
    shift
    ;;
esac
done


DEFAULT_USER=$(whoami)
USER="${USER_PARAM:-$DEFAULT_USER}"
DEFAULT_SSH_KEY="$HOME/.ssh/id_rsa"
SSH_KEY=${SSH_KEY_PARAM:-$DEFAULT_SSH_KEY}

if [ -z "$PROJECT" ]
then
    printf "\nplease provide '-p PROJECT_NAME' where you want to set your ssh_key\n\n"
    exit 1
fi

if [ ! -f "$SSH_KEY.pub" ]; then
    printf "\n$SSH_KEY.pub is not exist!, please add '-k key_name' for private key\n\n"
    exit 1
fi


jq -V > /dev/null 2>&1 || jq_not_installed

gcloud compute project-info describe --format='json' --project=$PROJECT | \
    jq -r '.commonInstanceMetadata.items[] | select(.key=="ssh-keys") | .value' | \
    grep -v -e "${USER}" -e "^$" > $TEMP_KEYS
printf "%s:%s\n" "${USER}" "$(cat ${SSH_KEY}.pub)" >> $TEMP_KEYS

if  [ $(cat $TEMP_KEYS|wc -l ) -le "1" ]
then
    printf "\nsomething is going wrong - probably you will rewrite all keys with your only please ask for help\n\n"
    exit 1
fi

gcloud compute project-info add-metadata --metadata-from-file ssh-keys=$TEMP_KEYS --project=$PROJECT
rm -f $TEMP_KEYS