...sorry, not an answer to your ansible question, but in Google Cloud Platform you can use the instance name instead of an IP address and that will resolve to the instance, whatever its IP - so you may not need a static IP at all.
Appsbroker Consulting Limited, Registered office: Appsbroker House, The Square, Swindon,
SN1 3EB, Company Number: 5702796, VAT Number: GB 876 3533 92, Company registered in England and Wales.
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