Text you and alert Slack when a metric crosses a threshold

from twilio.rest import Client
from clickruntime import on_trigger, credentials, http, notify, state

METRIC_URL = "https://metrics.example.com/api/error-rate"
LIMIT = 5.0
ON_CALL = "+447700900123"
FROM = "+15005550006"

def sms(to, body):
    return Client(credentials.secret("TWILIO_ACCOUNT_SID"), credentials.secret("TWILIO_AUTH_TOKEN")).messages.create(to=to, from_=FROM, body=body)

@on_trigger
def run(event):
    value = float(http.get(METRIC_URL, headers={"Authorization": f"Bearer {credentials.secret('METRICS_TOKEN')}"}).json()["value"])
    breached, was = value > LIMIT, bool(state.get("breached"))
    if breached and not was:
        sms(ON_CALL, f"⚠️ Error rate {value:.1f}% (limit {LIMIT:.0f}%)")
        notify.slack(f":rotating_light: Error rate is {value:.1f}% (limit {LIMIT:.0f}%)", channel="#ops")
    elif was and not breached:
        notify.slack(f":white_check_mark: Error rate back to {value:.1f}%", channel="#ops")
    state.set("breached", breached)
    return {"value": value}