Cron Container

To launch a container on a schedule, you can use a Workers Cron Trigger.

For a full example, see the Cron Container Template ↗.

Use a cron expression in your Wrangler config to specify the schedule:

wrangler.jsonc

{
  "name": "cron-container",
  "main": "src/index.ts",
  "triggers": {
    "crons": [
      "*/2 * * * *" // Run every 2 minutes
    ]
  },
  "containers": [
    {
      "class_name": "CronContainer",
      "image": "./Dockerfile"
    }
  ],
  "durable_objects": {
    "bindings": [
      {
        "class_name": "CronContainer",
        "name": "CRON_CONTAINER"
      }
    ]
  },
  "migrations": [
    {
      "new_sqlite_classes": ["CronContainer"],
      "tag": "v1"
    }
  ]
}

wrangler.toml

name = "cron-container"
main = "src/index.ts"

[triggers]
crons = [ "*/2 * * * *" ]

[[containers]]
class_name = "CronContainer"
image = "./Dockerfile"

[[durable_objects.bindings]]
class_name = "CronContainer"
name = "CRON_CONTAINER"

[[migrations]]
new_sqlite_classes = [ "CronContainer" ]
tag = "v1"

Then in your Worker, call your Container from the "scheduled" handler:

TypeScript

import { Container, getContainer } from '@cloudflare/containers';

export class CronContainer extends Container {
  sleepAfter = '10s';

  override onStart() {
    console.log('Starting container');
  }

  override onStop() {
    console.log('Container stopped');
  }
}

export default {
  async fetch(): Promise<Response> {
    return new Response("This Worker runs a cron job to execute a container on a schedule.");
  },

  async scheduled(_controller: any, env: { CRON_CONTAINER: DurableObjectNamespace<CronContainer> }) {
    let container = getContainer(env.CRON_CONTAINER);
    await container.start({
      envVars: {
        MESSAGE: "Start Time: " + new Date().toISOString(),
      }
    })
  },
};