Function purgeEdgeCache

script/deployment/purge-edge-cache.js:30–75

(
  surrogateKey,
  {
    purgeTwice = true,
    delayBeforeFirstPurge = DELAY_BEFORE_FIRST_PURGE,
    delayBeforeSecondPurge = DELAY_BEFORE_SECOND_PURGE,
  } = {}
)

}

export default async function purgeEdgeCache(
  surrogateKey,
  {
    purgeTwice = true,
    delayBeforeFirstPurge = DELAY_BEFORE_FIRST_PURGE,
    delayBeforeSecondPurge = DELAY_BEFORE_SECOND_PURGE,
  } = {}
) {
  if (!surrogateKey) {
    throw new Error('No key set and/or no FASTLY_SURROGATE_KEY env var set')
  }
  console.log(`Fastly purgeEdgeCache initialized for: '${surrogateKey}'`)

  const { FASTLY_TOKEN, FASTLY_SERVICE_ID } = process.env
  if (!FASTLY_TOKEN || !FASTLY_SERVICE_ID) {
    throw new Error('Fastly env vars not detected; skipping purgeEdgeCache step')
  }

  const purgingParams = {
    apiToken: FASTLY_TOKEN,
    serviceId: FASTLY_SERVICE_ID,
    surrogateKey,
  }

  // Give the app some extra time to wake up before the thundering herd of
  // Fastly requests.
  if (delayBeforeFirstPurge) {
    console.log('Waiting extra time to prevent a Thundering Herd problem...')
    await sleep(delayBeforeFirstPurge)
  }

  console.log('Attempting first Fastly purge...')
  const firstPurge = await purgeFastlyBySurrogateKey(purgingParams)
  console.log('First Fastly purge result:', firstPurge.body || firstPurge)

  // Evidence has shown that it's necessary to purge twice to ensure all
  // customers see fresh content.
  if (purgeTwice) {
    console.log('Waiting to purge a second time...')
    await sleep(delayBeforeSecondPurge)

    console.log('Attempting second Fastly purge...')
    const secondPurge = await purgeFastlyBySurrogateKey(purgingParams)
    console.log('Second Fastly purge result:', secondPurge.body || secondPurge)
  }
}