require 'stackdriver'

# One time setup
api_key = "foo"
StackDriver.init api_key

# Send single metric value
StackDriver.send_metric "test_metric", 666, Time.now.to_i

# Send single metric value with instance id
Stackdriver.send_metric "test_metric", 666, Time.now.to_i, "i-12345"

# Send multiple metric values with instance_id
Stackdriver.send_multi_metric data_point_array

where data is an array of this type:
data = [
  {
     'name': 'my_custom_metric1',
     'value': 32,
     #Note: Stackdriver rejects when the collected_at value is older than 2 hours.
     'collected_at': 1325394000,
     #Note: Include an instance value if your metric is tied to an instance.
     #'instance': 'i-XXXXXXXX',
  },
  {
     'name': 'my_custom_metric2',
     'value': 37,
     #Note: Stackdriver rejects when the collected_at value is older than 2 hours.
     'collected_at': 1325394000,
     #Note: Include an instance value if your metric is tied to an instance.
     #'instance': 'i-XXXXXXXX',
  }
]