ruby-google-calendar.rb

require 'rubygems'
require 'google/api_client'

client = Google::APIClient.new(
    application_name: 'Ruby Google Calendar Example',
    application_version: '1.0.0')
    
calendar = client.discovered_api('calendar', 'v3')
key       = Google::APIClient::PKCS12.load_key('./keys/creds.p12', 'notasecret')
asserter  = Google::APIClient::JWTAsserter.new(
    '<replace-with-your-service-account>@developer.gserviceaccount.com',
    'https://www.googleapis.com/auth/calendar',
    key)
client.authorization = asserter.authorize

query = { api_method: calendar.events.list,
          parameters:
          { 'calendarId' => 'youremail@gmail.com',
            'singleEvents' => true,
            'maxResults' => 2500 }
          }
          
result = client.execute(query)