First sandbox (demo + real shell)

By the end of this lesson you will understand the real commands to run a Linux microVM and open a shell. Prefer the interactive demo first, then run the same steps on your machine.

For the shortest path (install + starter config + cleanup), use Quick start. Custom first-boot setup (packages, scripts) before ready: Bootstrap until ready.

Interactive demo

Simulated terminal — nothing runs on your computer. Type the suggested commands or click Run step. After grain sh, try guest commands like uname -a, then exit.

~ — grain — interactive demo

Do it for real

1. Start the daemon

bash

grain up

This starts the local control plane in the background. You should see the unix socket path (default ~/.grain/grain.sock) and optional TCP API address (default http://127.0.0.1:7474).

Check that it is up:

bash

grain ls
# no vms — create one:  grain new

2. Pull a base image (once)

Prefer the golden image with the guest agent baked in:

bash

grain image pull grain-ubuntu

If that release asset is not published yet on your arch, use the Ubuntu cloud image:

bash

grain image pull ubuntu-cloud

List what you have:

bash

grain image ls

3. Create a sandbox

bash

grain new

With a golden image ready, grain defaults to agent wait. You will see progress phases (image → disk → seed → boot → waiting agent) and a final line similar to:

text

created sbox-1  status=running  image=grain-ubuntu  persist=false  ssh=:PORT
next:  grain sh sbox-1

Useful flags later:

Flag	Meaning
`-p`	Persistent disk
`-n NAME`	Explicit name
`-P 8080:80`	Publish host port
`-v $PWD:/work`	Share a host directory
`--wait agent`	Fail create if agent never becomes healthy

4. Open a shell

bash

grain sh

If only one VM exists, the name is optional. grain prefers the guest agent PTY when the agent is healthy; use grain sh --ssh for classic SSH.

Run a non-interactive command:

bash

grain x -- uname -a

5. Clean up

bash

grain rm          # or: grain stop  (ephemeral VMs are deleted on stop)
grain down        # stop the daemon when you are done for the day

What you learned

The daemon must be running for VM commands
Images are pulled once, then cloned per VM
sh / x talk to the guest agent when possible
Ephemeral VMs are disposable by design

Next: Quick start (config + common flags), Core concepts, Bootstrap until ready for custom setup, then a guide for mounts, proxy, or k3s.