gistfile1.txt

      #cloud-config
        write_files:
        - path: /root/hello-world.txt
          content: |
            #!/bin/bash
            username=XXXXXX
            APIkey=XXXXXX
            dc=hkg
            container=dn-container
            file=xyz.tar.gz

            token() {
                   token=`curl -s "https://identity.api.rackspacecloud.com/v2.0/tokens" -X POST \
                   -d '{"auth":{"RAX-KSKEY:apiKeyCredentials":{"username":"'$username'", "apiKey":"'$APIkey'"}}}' \
                   -H "Content-Type: application/json" | python -m json.tool  | sed -n '/expires/{n;p;}' |sed -e 's/^.*"id": "\(.*\)",/\1/'`
                   echo "Your API Token is ---->  $token" > /root/token.txt
                 }
            token
            
Output (in cloud server):
root@test-server:~# cat hello-world.txt
username=XXXXXX
APIkey=XXXXXX
dc=hkg
container=dn-container
file=xyz.tar.gz

token() {
       token=`curl -s "https://identity.api.rackspacecloud.com/v2.0/tokens" -X POST undefined
       -d '{"auth":{"RAX-KSKEY:apiKeyCredentials":{"username":"'$username'", "apiKey":"'$APIkey'"}}}' undefined
       -H "Content-Type: application/json" | python -m json.tool  | sed -n '/expires/{n;p;}' |sed -e 's/^.*"id": "undefined(.*undefined)",/undefined1/'`
       echo "Your API Token is ---->  $token" > /root/token.txt
     }
token