How can I authorize a Google Service Account without the default credentials file?

Question

I have a Google Service Account that my app uses to retrieve data from Google Analytics.

When I created the account I downloaded a client_secrets file with

Answer 1

I found this

require "google/cloud/bigquery"

ENV["BIGQUERY_PROJECT"]     = "my-project-id"
ENV["BIGQUERY_CREDENTIALS"] = "path/to/keyfile.json"

bigquery = Google::Cloud::Bigquery.new

more detail:

https://github.com/googleapis/google-cloud-ruby/blob/master/google-cloud-bigquery/AUTHENTICATION.md