If you want to use Google APIS from server side nodejs, authentication can be complicated for services such as sheets, especially for automated processes that don't have human interaction.
I noticed that the examples in the api docs are mainly pythonesque and feature 3 legged auth, so here's how to impersonate a domain member using a service account minus the complicated Oauth2 dance. This example uses the Sheets API but most other APIS will work the same way.
http://ramblings.mcpher.com/Home/excelquirks/vuejs-and-apollo-graphql/google-cloud-platform/sheesapiimpersonate