How to create a node.js Native Image with GraalVM

Question

I am trying to create a native image from a simple node.js example.js application.

When running the application with:

 node --native -i --native example.js

then the application is starting and working as expected.

Now I would like to create a native image. I tried the following command:

 native-image --language:js example.js

however it is not working, because of the error:

Build on Server(pid: 77626, port: 64052)
[example.js:77626]    classlist:   3,964.04 ms
error: Main entry point class 'example.js' not found.
Error: Processing image build request failed

As a resolution I created a main entry point in example.js such as:

function main(args) {
  console.log("Main app started")
}

however this doesn't work.

Is there a way usually native images are create for js/node.js applications?

Answer 1

No. Currently, as of Dec 2018, creating GraalVM native images for node.js applications is not possible. The native image utility takes Java bytecode and compiles it ahead of time. GraalVM JavaScript engine is a Java program and can be compiled as a native image. This is what you actually run when you execute $GRAALVM_HOME/bin/js. It still loads JavaScript at runtime, interprets it and compiles it just-in-time to machine code.

GraalVM's node implementation is a normal node, a native application, with the JavaScript engine replaced by the GraalVM's one.

The GraalVM team is experimenting with possible ways to save precompiled parts of the JavaScript programs, maybe a standard library, or parts of your application, but when this can become available and in which form is unclear.