Push a generic metric name/number to GCP (excerpt of bigger script)

gcp-write-metric-excerpt.rb

#!/usr/bin/env ruby

# full script here: https://github.com/palladius/sakura/blob/master/bin/gcp-write-metric 

require 'google/cloud/monitoring'
require 'socket' # for hostname
require 'openssl'
require 'colorize' # makes life worth living

# I want to know server side who called me
def gethostname
  Socket.gethostname
end

def magic_cloud_console_url(project_id)
  'https://console.cloud.google.com/monitoring/metrics-explorer?project=#{project_id}&pageState=%7B%22xyChart%22:%7B%22dataSets%22:%5B%7B%22timeSeriesFilter%22:%7B%22filter%22:%22metric.type%3D%5C%22custom.googleapis.com%2Friccardo-disc-free-pct%5C%22%20resource.type%3D%5C%22gce_instance%5C%22%22,%22minAlignmentPeriod%22:%2260s%22,%22aggregations%22:%5B%7B%22perSeriesAligner%22:%22ALIGN_MEAN%22,%22crossSeriesReducer%22:%22REDUCE_NONE%22,%22alignmentPeriod%22:%2260s%22,%22groupByFields%22:%5B%5D%7D,%7B%22crossSeriesReducer%22:%22REDUCE_NONE%22,%22alignmentPeriod%22:%2260s%22,%22groupByFields%22:%5B%5D%7D%5D%7D,%22targetAxis%22:%22Y1%22,%22plotType%22:%22LINE%22%7D%5D,%22options%22:%7B%22mode%22:%22COLOR%22%7D,%22constantLines%22:%5B%5D,%22timeshiftDuration%22:%220s%22,%22y1Axis%22:%7B%22label%22:%22y1Axis%22,%22scale%22:%22LINEAR%22%7D%7D,%22isAutoRefresh%22:true,%22timeSelection%22:%7B%22timeRange%22:%221h%22%7D%7D'
end

def write_generic_metric(project_id, metric_label, metric_value)
  metric_service_client = Google::Cloud::Monitoring.metric_service
  project_path = metric_service_client.project_path project: project_id

  full_hostname = gethostname()
  hostname = full_hostname.split('.')[0]
  host_domain = full_hostname.split('.')[1,10].join('.')

  series = Google::Cloud::Monitoring::V3::TimeSeries.new
  series.metric = Google::Api::Metric.new type:   "custom.googleapis.com/#{metric_label}",
                      labels: {
                        "my_key" => metric_label,
                        "hostname" =>  hostname,
                        "domain"   =>  host_domain,
                        #"app_verison" =>  $APP_VERSION, # found out you dont want to slice and dice metric when you change version... but you might want it.
                      }

  resource = Google::Api::MonitoredResource.new type: "gce_instance"
  resource.labels["project_id"] = project_id
  resource.labels["instance_id"] = hostname # "1234567890123456789"
  resource.labels["zone"] = "europe-west6-a" #  Zurich - "us-central1-f"
  series.resource = resource

  point = Google::Cloud::Monitoring::V3::Point.new
  point.value = Google::Cloud::Monitoring::V3::TypedValue.new double_value: metric_value # get_disk_space

  now = Time.now
  end_time = Google::Protobuf::Timestamp.new seconds: now.to_i, nanos: now.nsec
  point.interval = Google::Cloud::Monitoring::V3::TimeInterval.new end_time: end_time
  series.points << point

  metric_service_client.create_time_series name: project_path, time_series: [series]

  puts "📉 Successfully wrote time series '#{metric_label.colorize :yellow}'=#{metric_value.to_s.colorize :cyan} on #{project_id.colorize :red} for '#{hostname}'"
end


def main
  metric = ARGV[0]
  value = ARGV[1].to_f

  write_generic_metric(project_id, metric, value)
end

main()

shortened script for Medium article. Fill script in here however: https://github.com/palladius/sakura/blob/master/bin/gcp-write-metric