The gsutil setmeta command allows you to set or remove the metadata on one or more objects. It takes one or more header arguments followed by one or more URLs, where each header argument is in one of two forms:

gsutil setmeta -h [header:value|header] ... url...

setmeta to a object If you want to set cache-control to "public" then execute in Cloud Shell:

gsutil setmeta -h "Cache-Control:public" gs://<YOUR-BUCKET-NAME>/objectName

setmeta to multiple object If you want to set cache-control to "public" then execute in Cloud Shell:

gsutil setmeta -h "Cache-Control:public" gs://<YOUR-BUCKET-NAME>/*.*

*.* will add add the files inside the directory

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