Cube Sandbox

English

简体中文

English

简体中文

Appearance

Connect to an Existing Cube Cluster ​

To get started quickly, check out the example directory:

Why we need dev-sidecar ​

E2B expects sandbox URLs to resolve to the target cluster's public IP through wildcard DNS. In a production deployment, that usually means adding a private DNS A record like:

text
*.cube.app => <your cube master node ip>

That is inconvenient during local development. Setting up wildcard DNS on a developer machine is usually the annoying part, so dev-sidecar exists to let you connect your local machine to a Cube cluster and create sandboxes without changing the E2B SDK itself.

This page only does one thing: help you quickly decide how to fill the dev-sidecar environment variables.

Start With the Happy Path ​

Case 1: You started Cube locally with dev-env ​

This is the most natural and recommended development path for dev-sidecar.

If you followed Development Environment (QEMU VM), the defaults in examples/e2b-dev-sidecar/env.example were already chosen for this exact case.

Do this:

bash
cd examples/e2b-dev-sidecar
pip install -r requirements.txt
cp env.example .env

Then usually you only need to fill in the template ID:

bash
E2B_API_URL="http://127.0.0.1:13000"
CUBE_REMOTE_PROXY_BASE="https://127.0.0.1:11443"
E2B_API_KEY="dummy"
CUBE_TEMPLATE_ID="<your-template-id>"

Run:

bash
python demo.py

The key point is:

  • 127.0.0.1:13000 is not arbitrary. It is the CubeAPI endpoint exposed by dev-env.
  • 127.0.0.1:11443 is not arbitrary. It is the CubeProxy endpoint exposed by dev-env.

So if you already booted local dev-env, you usually do not need to change the addresses. You mostly just fill in the template ID.

Case 2: You want to connect to a Cube cluster on another machine ​

You still use the same dev-sidecar example. You only replace the default addresses with the real endpoints of that remote cluster:

bash
E2B_API_URL="http://<node-ip>:3000"
CUBE_REMOTE_PROXY_BASE="https://<node-ip>:443"
E2B_API_KEY="dummy"
CUBE_TEMPLATE_ID="<your-template-id>"

Then run the same command:

bash
python demo.py

Just Remember These ​

  • E2B_API_URL Control-plane endpoint. In dev-env, the default is http://127.0.0.1:13000.
  • CUBE_REMOTE_PROXY_BASE Data-plane endpoint. In dev-env, the default is https://127.0.0.1:11443.
  • E2B_API_KEY Must be non-empty for the SDK. If auth is enabled, use the real key.
  • CUBE_TEMPLATE_ID The template ID used when creating the sandbox.

You usually do not need to think about the other variables first. For most development flows, getting these four values right is enough.

Common Mistakes ​

  • You are using local dev-env, but configured the in-VM addresses instead of the host-exposed 13000/11443 ports
  • You pointed CUBE_REMOTE_PROXY_BASE at the sidecar's own listening address instead of CubeProxy
  • You forgot to set CUBE_TEMPLATE_ID
  • Auth is enabled on the cluster, but E2B_API_KEY is still dummy

Further Reading ​

If you want the easiest explanation, go straight to the example README:

If you are ready to wire the sidecar into your own code, then look at:

  • demo.py
  • dev_sidecar.py