CF-Incidents Containers - New scheduling policy for Containers to configure image and instance from Durable Objects

[ENF News Bot]

Containers now support the durable_object scheduling policy in public beta. This policy lets a Durable Object select the image and instance size for a Container at runtime instead of using one centrally managed configuration for the application.

To use custom images, configure the policy and one or more named images in Wrangler:

{
	"containers": [
		{
			"class_name": "AgentComputer",
			"scheduling_policy": "durable_object",
			"images": {
				"base": {
					"dockerfile": "./container/Dockerfile",
				},
			},
		},
	],
}

[[containers]]
class_name = "AgentComputer"
scheduling_policy = "durable_object"

[containers.images.base]
dockerfile = "./container/Dockerfile"

Wrangler prepares each image and exposes its immutable reference through ctx.container.images. Supply that reference and an instance size when you start the Container:

src/index.jsjs

this.ctx.container.start({
	image: this.ctx.container.images.base,
	enableInternet: false,
	instance: "standard-2",
});

src/index.tsts

this.ctx.container.start({
	image: this.ctx.container.images.base,
	enableInternet: false,
	instance: "standard-2",
});

The durable_object policy also supports the new cloudflare/debian-trixie Cloudflare-managed image, which includes Node.js 24.20.0 on Debian Trixie slim. Start it directly without configuring a named image.

Durable Object-managed Container instances have independent lifecycles and do not participate in application-wide image rollouts.

For configuration, runtime sizing, snapshots, and update behavior, refer to Scheduling Policies.

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