Move backups

COPY --from=docker.io/cloudflare/sandbox:1.0.0 /usr/local/bin/sandbox-shim /usr/local/bin/sandbox-shim

import {
	DirectoryBackup,
	type DirectoryBackupRecord,
} from "@cloudflare/sandbox";

// Gives the Durable Object this.ctx.exports.DirectoryBackupGateway,
// which moves each backup between the container and the bucket
export { DirectoryBackupGateway } from "@cloudflare/sandbox";

// 0.12 kept a backup for three days unless you set ttl.
const DEFAULT_TTL_SECONDS = 3 * 24 * 60 * 60;

// The record your code stores in place of the 0.12 backup object.
type Backup = DirectoryBackupRecord & { expiresAt: number };

// Restores read the expiry time from this object, because a caller
// can change the expiresAt field of a record.
const metaKey = (id: string) => `backups/${id}.meta.json`;

// Like 0.12, refuse a backup that expires within a minute.
const EXPIRY_MARGIN_MS = 60 * 1000;

export class MySandbox extends DurableObject<Env> {
	// ...

	private readonly backups = new DirectoryBackup(
		this.container,
		this.ctx.exports.DirectoryBackupGateway,
		{ binding: "BACKUP_BUCKET", prefix: "backups/" },
	);
}

const sandbox = getSandbox(env.Sandbox, "ada");
const backup = await sandbox.createBackup({
	dir: "/workspace/project",
	excludes: ["node_modules"],
	ttl: 24 * 60 * 60,
});

export class MySandbox extends DurableObject<Env> {
	// ...

	async createBackup(options: {
		dir: string;
		name?: string;
		excludes?: string[];
		gitignore?: boolean;
		ttl?: number;
	}): Promise<Backup> {
		await this.ensureRunning();
		const { excludes, ttl = DEFAULT_TTL_SECONDS, ...rest } = options;
		const backup = await this.backups.backup({
			...rest,
			// 0.12 matched each pattern from the top of the directory.
			exclude: excludes?.map((pattern) => `/${pattern}`),
		});
		const expiresAt = Date.now() + ttl * 1000;
		await this.env.BACKUP_BUCKET.put(
			metaKey(backup.id),
			JSON.stringify({ expiresAt }),
		);

		return { ...backup, expiresAt };
	}
}

export class MySandbox extends DurableObject<Env> {
	// ...

	async restoreBackup(backup: DirectoryBackupRecord) {
		const meta = await this.env.BACKUP_BUCKET.get(metaKey(backup.id));

		if (!meta) {
			throw new Error(`Backup ${backup.id} was not found`);
		}

		const { expiresAt } = await meta.json<{ expiresAt: number }>();

		if (Date.now() + EXPIRY_MARGIN_MS > expiresAt) {
			throw new Error(`Backup ${backup.id} has expired`);
		}

		await this.ensureRunning();
		await this.backups.restore(backup);
		return { success: true, dir: backup.dir, id: backup.id };
	}
}

RUN apt-get update && apt-get install -y --no-install-recommends squashfs-tools && rm -rf /var/lib/apt/lists/*

export class MySandbox extends DurableObject<Env> {
	// ...

	async convert(old: { id: string; dir: string }): Promise<Backup> {
		const meta = await this.env.BACKUP_BUCKET.get(`backups/${old.id}/meta.json`);
		const image = await this.env.BACKUP_BUCKET.get(`backups/${old.id}/data.sqsh`);

		if (!meta || !image) {
			throw new Error(`Backup ${old.id} was not found`);
		}

		const { createdAt, ttl } = await meta.json<{ createdAt: string; ttl: number }>();
		const expiresAt = Date.parse(createdAt) + ttl * 1000;

		if (Date.now() + EXPIRY_MARGIN_MS > expiresAt) {
			await image.body.cancel();
			throw new Error(`Backup ${old.id} has expired`);
		}

		await this.ensureRunning();

		// unsquashfs needs the whole image on disk, so it goes to /var/tmp first.
		const script =
			'cat > "$1" && rm -rf -- "$2" &&' +
			' unsquashfs -no-progress -d "$2" "$1" > /dev/null;' +
			' code=$?; rm -f -- "$1"; exit $code';
		const process = await this.container.exec(
			["sh", "-c", script, "sh", `/var/tmp/${old.id}.sqsh`, old.dir],
			{ stdin: image.body },
		);
		const output = await process.output();

		if (output.exitCode !== 0) {
			throw new Error(new TextDecoder().decode(output.stderr));
		}

		const backup = await this.backups.backup({ dir: old.dir });
		await this.env.BACKUP_BUCKET.put(
			metaKey(backup.id),
			JSON.stringify({ expiresAt }),
		);
		return { ...backup, expiresAt };
	}
}

await this.env.BACKUP_BUCKET.delete([
	`backups/${old.id}/data.sqsh`,
	`backups/${old.id}/meta.json`,
]);