Reading/writing to Google Storage from Google Compute Windows 2008 VM

Question

I have a Google Compute VM (LAMP) webserver set up to copy files to a Google Storage Bucket, which then need to be accessed (read and write) by a program on a Google Compute VM (Windows 2008). I can't seem to find any documentation about how a Google Compute Engine Windows VM can access storage buckets.

Is there a way this is possible? Thanks.

Answer 1

I'm doing the same thing, but not with a windows VM, but I think the principle is the same.

First you need to allow Project Access for your VM from the Google Cloud Console https://console.developers.google.com/project, see the screenshot below:

Once you've done this you need to call the metadata server to get an access token from your program. You need to make a HTTP call to the metadata server, here is an example from the docs (https://cloud.google.com/compute/docs/authentication) using curl, bear in mind when programming this you need to also provide the header "Metadata-Flavor: Google":

$ curl "http://metadata/computeMetadata/v1/instance/service-accounts/default/token" \ -H "Metadata-Flavor: Google"

{
  "access_token":"ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_QtAS08i85nHq39HE3C2LTrCARA",
  "expires_in":3599,
  "token_type":"Bearer"
}

You obviously need to code this HTTP call and the parsing of the JSON data in whichever programming language you are using for your program and extract the "access_token", based on the "expires_in" field you might also need to implement a mechanism to fetch a new token once it expires. You can then use the Google supplied cloud storage client library (https://cloud.google.com/storage/docs/json_api/v1/libraries) for your programming language and use the access token above for authenticating calls to cloud storage. I use Java and the Cloud storage class in the API library has this method that can be used:

.setOauthToken("blah")

Answer 2

You can mount the drive with CloudBerry. I would like to find a better way to do it though using only Google Cloud. Please let me know if you find anything better.