How to upload to Google Cloud Storage buckets using CURL

Signed URLs are pretty nifty feature given by Google Cloud Platform to let anyone access your cloud storage (bucket or any file in the bucket) without need to sign in.

Official documentation gives step by step details as to how to read/write to the bucket using gsutil or through a program. This article will tell you how to upload a file to the bucket using curl so that any client which doesn't have cloud SDK installed can do this using a simple script.

This command creates a signed PUT URL for your bucket.

 gsutil signurl -c 'text/plain' -m PUT serviceAccount.json gs://test_bucket_location  

Here is my URL:

 https://storage.googleapis.com/test_sl?GoogleAccessId=my-project-id@appspot.gserviceaccount.com&Expires=1490266627&Signature=UfKBNHWtjLKSBEcUQUKDeQtSQV6YCleE9hGG%2BCxVEjDOmkDxwkC%2BPtEg63pjDBHyKhVOnhspP1%2FAVSr%2B%2Fty8Ps7MSQ0lM2YHkbPeqjTiUcAfsbdcuXUMbe3p8FysRUFMe2dSikehBJWtbYtjb%2BNCw3L09c7fLFyAoJafIcnoIz7iJGP%2Br6gAUkSnZXgbVjr6wjN%2FIaudXIqAxyz4O6VU%2FIob8RHmfYBD3rYw8oRmZer0g%2BMTDw5Bu3%2BdjbxCriCOkOLWkvlpBGvd71hRP89lxpD%2FwX1N1pzAiRBpmKAhpKrYrq8h4kNLAtTHXYSz5j%2Bzb28UD4YMG52n8UpfyPgFIg%3D%3D  

Now this command will upload a text file to the bucket using the signed URL we created:

 $ curl -X PUT -H 'content-type: text/plain' -d @test_upload.txt https://storage.googleapis.com/test_sl?GoogleAccessId=my-project-id@appspot.gserviceaccount.com&Expires=1490266627&Signature=UfKBNHWtjLKSBEcUQUKDeQtSQV6YCleE9hGG%2BCxVEjDOmkDxwkC%2BPtEg63pjDBHyKhVOnhspP1%2FAVSr%2B%2Fty8Ps7MSQ0lM2YHkbPeqjTiUcAfsbdcuXUMbe3p8FysRUFMe2dSikehBJWtbYtjb%2BNCw3L09c7fLFyAoJafIcnoIz7iJGP%2Br6gAUkSnZXgbVjr6wjN%2FIaudXIqAxyz4O6VU%2FIob8RHmfYBD3rYw8oRmZer0g%2BMTDw5Bu3%2BdjbxCriCOkOLWkvlpBGvd71hRP89lxpD%2FwX1N1pzAiRBpmKAhpKrYrq8h4kNLAtTHXYSz5j%2Bzb28UD4YMG52n8UpfyPgFIg%3D%3D  

On similar lines, you can create a RESUMABLE URL and then upload file using following command:

 $ curl -v -X 'POST' -H 'content-type: text/plain' -H 'x-goog-resumable:start' '[signed url]' -d ''  

This command gives 'session URI' which is similar to signed url, but longer!

 $ curl -v -X PUT -d @test_upload.txt -H 'content-type: text/plain' '[session URI]'  

Simple isn't it!