FaaS Node.js Runtime Image

This image is meant to run in an OpenShift cluster with Knative installed. It is currently under development and incomplete. When a container for this image starts, a process loads the JavaScript in /home/node/usr on the container file system. If there is a package.json file in the directory, the bootstrap process will run npm install before loading the function.

Source to Image

This image may also be used as a source to image builder.

Limitations

• The image currently responds to HTTP requests on port 8080 and to Knative Events, which users can consume as CloudEvent object.
• The function is passed a Context object when it is called. This object currently contains little to no valuable information beyond the Node.js http.IncomingMessage (the request), http.ServerResponse objects and cloudevent object, which is instantiated if the function responds to incoming Knative Event.

Surely there are other limitations, but this is enough for plenty of discussion at the moment.

Building

To build the image, run the following command.

make build

You should end up with an image at redhat-faas/js-runtime.

Running locally

You can run this image locally to play around with it, test edges and generally get a feel for how it works. First, create a directory containing one or more JavaScript files. One of these must be named index.js. The bootstrap process will load this file and any other files it references via module dependencies (e.g. const myCalc = require('./my-calc.js');). If you have external, third party dependencies from npmjs.com, add a package.json to the directory specifying the dependencies.

With the source in place, you can start the container and mount the source onto a container directory. The bootstrap process expects /home/node/usr to contain the runtime source code. To mount this into a running container execute the following command.

docker run --rm -a stdout -a stderr -v /path/to/local/source/dir:/home/node/usr -p 8080:8080 oscf/js-runtime:candidate

To stop the running container:

$ docker ps
$ docker stop <CONTAINER ID>

Testing

To test the image, run the following command.

make test

This will build a candidate image, and mount the ./test directory on the host to the /home/node/usr directory on the running container. When the container starts, a bootstrap process loads the test JavaScript in /home/node/usr.