Schedule Cron jobs

periodic code execution: schedule a Cron job

We schedule a Cron job, with the help of Google Cloud's Cloud Scheduler. We register a job with onSchedule. We set:

• the periodicity, using strings such as every day 00:00 or every 8 hours.
• the timezone (IANA string), the region and the callback function:

export const updateRankingsCRON = onSchedule(
    {
        schedule: "every day 00:00",
        timeZone: "Europe/London",
        region: "europe-west1",
    },
    async () => {
        // ...
    },
)

The older API (v1) relied on pubsub instead:

export const updateRankingsCRON = functions.pubsub
    .schedule("every 8 hours")
    .timeZone("Europe/London")
    .onRun(async (context) => {
        // ..
    })