Setting required to configure concourse CI to use Google oAuth:

CONCOURSE_GENERIC_OAUTH_DISPLAY_NAME: "Google"
CONCOURSE_GENERIC_OAUTH_CLIENT_ID: "$google_oauth_client_id"
CONCOURSE_GENERIC_OAUTH_CLIENT_SECRET: "$google_oauth_client_secret"
CONCOURSE_GENERIC_OAUTH_AUTH_URL: "https://accounts.google.com/o/oauth2/auth"
CONCOURSE_GENERIC_OAUTH_TOKEN_URL: "https://accounts.google.com/o/oauth2/token"
CONCOURSE_GENERIC_OAUTH_AUTH_URL_PARAM: scope:profile,hd:$your_domain_name