Fetching a project-scoped Keystone V3 Token using bash

keystonev3token.sh

#!/bin/bash
set -e

if [ -z "$OS_USERNAME" ]; then echo "Error: OS_USERNAME is unset"; exit 1; fi;
if [ -z "$OS_PASSWORD" ]; then echo "Error: OS_PASSWORD is unset"; exit 1; fi;
if [ -z "$OS_USER_DOMAIN_NAME" ]; then echo "Error: OS_USER_DOMAIN_NAME is unset"; exit 1; fi;
if [ -z "$OS_PROJECT_DOMAIN_NAME" ]; then echo "Error: OS_PROJECT_DOMAIN_NAME is unset"; exit 1; fi;
if [ -z "$OS_AUTH_URL" ]; then echo "Error: OS_AUTH_URL is unset"; exit 1; fi;
if [ -z "$OS_PROJECT_NAME" ]; then echo "Error: OS_PROJECT_NAME is unset"; exit 1; fi;

generate_post_data()
{
cat <<EOF
{
  "auth": {
      "identity": {
          "methods": [
              "password"
          ],
          "password": {
              "user": {
                  "domain": {
                      "name": "$OS_USER_DOMAIN_NAME"
                  },
                  "name": "$OS_USERNAME",
                  "password": "$OS_PASSWORD"
              }
          }
      },
      "scope": {
          "project": {
              "name": "$OS_PROJECT_NAME",
              "domain": {
                  "name": "$OS_PROJECT_DOMAIN_NAME"
              }
          }
      }
  }
}
EOF
}

response=$(curl -is \
    -H "Accept: application/json" \
    -H "Content-Type:application/json" \
    -X POST --data "$(generate_post_data)" "$OS_AUTH_URL/auth/tokens")

# we have to remove a trailing carriage return here so that we can return a clean token
token=$(echo "$response" | awk '/[Xx]-[Ss]ubject-[Tt]oken/ {print $2}' | tr -d '\r')

[ -z "$token" ] && echo -e "Error fetching token:\n$response" && exit 1;

echo "$token";