Checkpoints and Forks

A checkpoint is a point-in-time capture of a runtime’s state, writable filesystem changes, and restore metadata such as vCPU, memory, CPU architecture, and pinned image hashes.

Create a runtime and write state into it:

CLI

runta run --name source-demo --cpus 2 --memory 1024
runta exec source-demo -- sh -lc 'echo hello-from-runtime > /tmp/hello.txt'

Python

from runta import Runta

runta = Runta()
runtime = runta.runtimes.create("source-demo", vcpus=2, memory_mib=1024)
runtime.exec("echo hello-from-runtime > /tmp/hello.txt")

TypeScript

import { Runta } from "@runta/runta-sdk";

const runta = new Runta();
const runtime = await runta.runtimes.create("source-demo", {
  vcpus: 2,
  memoryMib: 1024,
});
await runtime.exec("echo hello-from-runtime > /tmp/hello.txt");

Create a checkpoint:

CLI

runta checkpoint create source-demo source-demo-checkpoint

Python

checkpoint = runtime.checkpoints.create(name="source-demo-checkpoint")

TypeScript

const checkpoint = await runtime.checkpoints.create("full", "source-demo-checkpoint");

List available checkpoints:

CLI

runta checkpoint ls

Python

checkpoints = runta.checkpoints.list()
for checkpoint in checkpoints:
    print(checkpoint.id, checkpoint.state)

Restore the checkpoint into a new runtime:

CLI

runta checkpoint restore source-demo-checkpoint restored-demo

Python

restored = runta.runtimes.create(
    "restored-demo",
    checkpoint_id=checkpoint.id,
)

TypeScript

const restored = await runtime.restore(checkpoint.id, {
  name: "restored-demo",
});

Verify that the restored runtime contains the captured state:

CLI

runta exec restored-demo -- cat /tmp/hello.txt

Python

result = restored.exec("cat /tmp/hello.txt")
print(result.stdout_text)

TypeScript

const result = await restored.exec("cat /tmp/hello.txt");
console.log(result.stdoutText);

Fork the same checkpoint into another runtime:

CLI

runta checkpoint restore source-demo-checkpoint fork-demo

Python

fork = runta.runtimes.create("fork-demo", checkpoint_id=checkpoint.id)

TypeScript

const fork = await runtime.restore(checkpoint.id, {
  name: "fork-demo",
});