Simplified example of using google-cloud-monitoring to store custom metrics of my daemons RAM/fd leakage

example.rb

require "google/cloud/monitoring/v3/metric_service_client"
client = Google::Cloud::Monitoring::V3::MetricServiceClient.new
project_path = Google::Cloud::Monitoring::V3::MetricServiceClient.project_path JSON.load(File.read ENV["GOOGLE_APPLICATION_CREDENTIALS"])["project_id"]

create_custom_gauge_metric = lambda do |type, display_name, value_type, labels = {}|
  metric_descriptor = Google::Api::MetricDescriptor.new(                                  # googleapis-common-protos-1.3.5/lib/google/api/metric_pb.rb
    type: "custom.googleapis.com/#{type}",
    metric_kind: :GAUGE,                                                                  # google-cloud-monitoring-0.24.0/lib/google/cloud/monitoring/v3/doc/google/api/metric.rb
    value_type: value_type,                                                               # google-cloud-monitoring-0.24.0/lib/google/cloud/monitoring/v3/doc/google/api/metric.rb
    display_name: display_name,
  )
  labels.each do |label|
    metric_descriptor.labels.push Google::Api::LabelDescriptor.new(key: label)            # gcloud-0.12.0/lib/google/api/label.rb
  end
  client.create_metric_descriptor project_path, metric_descriptor
end

log_custom_metric = lambda do |type, timestamp, value, resource: nil, labels|
  time_series = Google::Monitoring::V3::TimeSeries.new(                                   # google-cloud-monitoring-0.24.0/lib/google/monitoring/v3/metric_pb.rb
    metric: Google::Api::Metric.new(                                                      # googleapis-common-protos-1.3.5/lib/google/api/metric_pb.rb
      type: "custom.googleapis.com/#{type}",
      labels: labels,
    ),
    **(resource ? {resource: Google::Api::MonitoredResource.new(**resource)} : {})        # googleapis-common-protos-1.3.5/lib/google/api/monitored_resource_pb.rb
  )
  time_series.points.push Google::Monitoring::V3::Point.new(                              # google-cloud-monitoring-0.24.0/lib/google/monitoring/v3/metric_pb.rb
    interval: Google::Monitoring::V3::TimeInterval.new(
      start_time: Google::Protobuf::Timestamp.new(seconds: timestamp.to_i),
      end_time: Google::Protobuf::Timestamp.new(seconds: timestamp.to_i),
    ),
    value: Google::Monitoring::V3::TypedValue.new(**value)                                # google-cloud-monitoring-0.24.0/lib/google/monitoring/v3/common_pb.rb
  )
  client.create_time_series project_path, [time_series]
end


create_custom_gauge_metric["test/free", "Vmstat.memory.free (MB)", :INT64]
create_custom_gauge_metric["test/mem", "GetProcessMem (MB)", :DOUBLE, ["daemon_id"]]
create_custom_gauge_metric["test/fd", "File descriptor count", :INT64, ["daemon_id"]]

require "yaml"
report = YAML.load DATA.read
timestamp, free, apps = report[:data]

log_custom_metric["test/free", timestamp, {int64_value: free}, resource: {type: "gce_instance", labels: {
  "instance_id"=>"0000000000000000000",
  "zone"=>"us-central1-a",
} } ]
apps.each do |daemon_id, mem, fd|
  log_custom_metric["test/mem", timestamp, {double_value: mem}, labels: {"daemon_id"=>daemon_id}]
  log_custom_metric["test/fd", timestamp, {int64_value: fd}, labels: {"daemon_id"=>daemon_id}]
end


__END__

---
:data:
- 2017-06-13 17:25:05.510724432 +00:00
- 1072
- - - "daemon 1"
    - 106.4765625
    - 63
  - - "daemon 2"
    - 26.8125
    - 52
  - - "daemon 3"
    - 743.1796875
    - 60