How to authenticate to Google Cloud API without Application Default Credentials or Cloud SDK?

Question

I'm trying to access the Google Cloud API from an AWS Lambda function but I don't know how to authenticate. The auth guide in the Google Cloud documentation (https://cloud.google.com/docs/authentication) wants me to download a credentials JSON file and use Application Default Credentials, but as anyone who has used hosted functions already knows, the point is that you don't need to manage a server or runtime environment, so Lambda doesn't give me the ability to store arbitrary files in the environment of the running code.

I can use the Cloud SDK locally to get an access token but it expires so I can't use it in my function as a permanent solution.

Is there not a way I can get an access token that I can use indefinitely in my code to call the Google Cloud API? Is there any other solution?

What language you are programming in? What google api library you using? — cherba
My AWS Lamba function is written in Javascript on Node JS and I'm calling Google's Natural Language APIs. — Mohamed Fakhreddine
Have you tried github.com/google/google-auth-library-nodejs to manage credentials? — cherba
That library is an implementation of Application Default Credentials and still requires you to download the JSON credentials file, which I cannot do in the AWS Lambda function environment. — Mohamed Fakhreddine
Yes, I assume you would download that JSON key file, and embed its content in your code. You do not need to load it from a file, one can hardcode the credentials assuming your code is secure. — cherba

Mohamed Fakhreddine Mohamed Fakhreddine · Accepted Answer · 2017-01-10T21:35:54

I found how to hard-code the credentials without the need to save them in a JSON file. It was in this documentation here:

https://googlecloudplatform.github.io/google-cloud-node/#/docs/language/0.7.0/guides/authentication

Below is an example that calls the Language API.

var language = require('@google-cloud/language')({
  projectId: '',
  credentials: {
      client_email: '',
      private_key: '',
  }
});

language.detectEntities('Axel Foley is from Detroit').then(function(data) {
  var entities = data[0];
  var apiResponse = data[1];
});

How to authenticate to Google Cloud API without Application Default Credentials or Cloud SDK?

1 Answers