Google Monitoring: Write a Custom Metric

write_custom_metric.py

!pip install --upgrade google-cloud-monitoring
from google.cloud import monitoring_v3

import time


def create_custom_ts(metric_name="my_metric"):
    series = monitoring_v3.TimeSeries()
    # https://cloud.google.com/monitoring/custom-metrics/creating-metrics
    series.metric.type = f"custom.googleapis.com/{metric_name}"

    # A common practice is to use the monitored resource objects that represent the physical resources where your application code is running
    # The resource labels varies by type, but are documented poorly
    series.resource.type = "gce_instance"
    series.resource.labels["instance_id"] = "1234567890123456789"
    series.resource.labels["zone"] = "us-central1-f"

    return series


def log_ts_metric(value, project):
    ts = create_custom_ts()

    now = time.time()
    seconds = int(now)
    nanos = int((now - seconds) * 10 ** 9)
    interval = monitoring_v3.TimeInterval(
        {"end_time": {"seconds": seconds, "nanos": nanos}}
    )
    points = [monitoring_v3.Point({"interval": interval, "value": {"double_value": value}})]
    ts.points = points

    client = monitoring_v3.MetricServiceClient()
    client.create_time_series(request={"name": f"projects/{project}", "time_series": [ts]})
    print("Successfully wrote time series.")


log_ts_metric(value=3)
log_ts_metric(value=2)
log_ts_metric(value=2.3)