Continuous communication with the sandbox about vm2

[patriksimek]

Just released 3.0 with a lot of changes. It is now possible to use streams or external libraries inside the sandbox. There is no need for minimal example, just whitelist required modules and you're ready.

[0o-de-lally]

@patriksimek Can you take a look at the question again? I'm not sure I understand your answer.

Is it possible for the sandbox to communicate the scope outside of the sandbox? For example using 'pipe' or 'ipc' message options like in node child_process

[patriksimek]

Yes, in v3, sandboxed script can communicate with anything you allow it to. You don't even need to use ipc, you can just exchange objects, functions, everything...

[0o-de-lally]

@patriksimek Thanks. Though I can't see this in the docs. Can you give me a quick example?
I'm trying to 1) start the sandbox, 2) run a function outside the sandbox and 3) return the result back to the sandbox which is waiting for the outer function.

[0o-de-lally]

@patriksimek Sorry but I must be missing something obvious. What's the best practice for 'exchanging objects' as you describe?

[patriksimek]

You can do it like this:

const {VM} = require('.');
const vm = new VM({
	sandbox: {
		greet: (name) => `Hello ${name}!`
	}
});

console.log(vm.run(`greet('world')`));

[0o-de-lally]

@patriksimek thanks for your attention on this. But I'm having trouble seeing how to implement "continuous communication" as in the title of this issue. For example how could I asynchronously communicate between two sandboxes?

[patriksimek]

What exactly continuous communication means for you? You can create a function in one sandbox and pass it to another sandbox so once you call the function from second sandbox, it will call a code in first sandbox.

[0o-de-lally]

@patriksimek thanks for the response. I'm looking to have a sandbox call an asnyc function in another sandbox and wait for the callback. I don't want to nest the second sandbox within the first one. I'm not sure what you mean: " so once you call the function from second sandbox, it will call a code in first sandbox." Can you provide a brief example? Thanks again

[patriksimek]

Example:

const {NodeVM} = require('vm2');

const vm1 = new NodeVM();
const fn = vm1.run(`module.exports = function(callback) { callback(null, 123) }`);

const vm2 = new NodeVM({
	sandbox: {
		fn
	}
});
vm2.run(`fn((err, res) => { console.log(res); })`);