Default credential for app engine project accessing google cloud storage?

Question

I have an app engine project, I want to access my google cloud storage default bucket. The first step of getting a Credential object fails, doing the following on a live instance:

Credential creds = GoogleCredential.getApplicationDefault();

The exception message I get:

"The Application Default Credentials are not available. They are available if running in Google Compute Engine. Otherwise, the environment variable GOOGLE_APPLICATION_CREDENTIALS must be defined pointing to a file defining the credentials. See https://developers.google.com/accounts/docs/application-default-credentials for more information."

The doc here says that production app engine projects should have access to the default credentials?:

https://developers.google.com/identity/protocols/application-default-credentials

"3. If you are running in Google App Engine production, the built-in service account associated with the application will be used."

Is there some setup I'm missing?

My app engine version (gradle):

com.google.appengine:appengine-java-sdk:1.9.18

and google cloud storage lib version:

com.google.apis:google-api-services-storage:v1-rev35-1.20.0

Thanks

I know it's been long since this question was asked, but you can try to export this parameter with path to JSON file containing your private key data to set default google cloud account, export GOOGLE_APPLICATION_CREDENTIALS=/Users/googleCredentials.json — Yogesh Patil

Micro Micro · Accepted Answer · 2016-04-04T17:02:59

Go to Google Developers Console -> Credentials and create a default service account .json key. When you do that, it will download a file like default-account-credentials.json for you. You must then put that file somewhere in your app engine project. This file will be referenced when you call

Credential creds = GoogleCredential.getApplicationDefault();

However, before that works you must set the environmental variable to that files location. To do that open up your appengine-web.xml file and put this line into it:

<env-variables>
            <env-var name="GOOGLE_APPLICATION_CREDENTIALS"
                value="WEB-INF/default-account-credentials.json" />
        </env-variables>

Where value is the path to your .json creds file you just downloaded.

Now it will work. (your gradle imports are fine)

Default credential for app engine project accessing google cloud storage?

1 Answers