GoogleCloudPlatformFunctions Framework for Node.js
An open source FaaS (Function as a Service) framework based on Express for writing portable Node.js functions.
The Functions Framework lets you write lightweight functions that run in many different environments, including:
- Google Cloud Run functions
- Your local development machine
- Cloud Run and Cloud Run for Anthos
- Knative-based environments
The framework allows you to go from:
/**
* Send "Hello, World!"
* @param req https://expressjs.com/en/api.html#req
* @param res https://expressjs.com/en/api.html#res
*/
exports.helloWorld = (req, res) => {
res.send('Hello, World!');
};To:
curl http://my-url
# Output: Hello, World!All without needing to worry about writing an HTTP server or complicated request handling logic.
Watch this video to learn more about the Node Functions Framework.
Features
- Spin up a local development server for quick testing
- Invoke a function in response to a request
- Automatically unmarshal events conforming to the CloudEvents spec
- Portable between serverless platforms
Installation
Add the Functions Framework to your package.json file using npm.
npm install @google-cloud/functions-frameworkQuickstarts
Quickstart: Hello, World on your local machine
Create an
index.jsfile with the following contents:exports.helloWorld = (req, res) => { res.send('Hello, World'); };Run the following command:
npx @google-cloud/functions-framework --target=helloWorldOpen http://localhost:8080/ in your browser and see Hello, World.
Quickstart: Set up a new project
Create a
package.jsonfile usingnpm init:npm initCreate an
index.jsfile with the following contents:const functions = require('@google-cloud/functions-framework'); functions.http('helloWorld', (req, res) => { res.send('Hello, World'); });Now install the Functions Framework:
npm install @google-cloud/functions-frameworkAdd a
startscript topackage.json, with configuration passed via command-line arguments:"scripts": { "start": "functions-framework --target=helloWorld" }Use
npm startto start the built-in local development server:npm start ... Serving function... Function: helloWorld URL: http://localhost:8080/Send requests to this function using
curlfrom another terminal window:curl localhost:8080 # Output: Hello, World
Quickstart: Build a Deployable Container
Build a container from your function using the Functions buildpacks:
pack build \ --builder gcr.io/buildpacks/builder:v1 \ --env GOOGLE_FUNCTION_SIGNATURE_TYPE=http \ --env GOOGLE_FUNCTION_TARGET=helloWorld \ my-first-functionStart the built container:
docker run --rm -p 8080:8080 my-first-function # Output: Serving function...Send requests to this function using
curlfrom another terminal window:curl localhost:8080 # Output: Hello, World!
Run your function on serverless platforms
Google Cloud Run functions
The Node.JS runtime on Cloud Run functions utilizes the Node.JS Functions Framework. On Cloud Run functions, the Functions Framework is completely optional: if you don't add it to your package.json, it will be
installed automatically. For
After you've written your function, you can simply deploy it from your local
machine using the gcloud command-line tool.
Check out the Cloud Functions quickstart.
Container environments based on KNative
Cloud Run and Cloud Run for Anthos both implement the Knative Serving API. The Functions Framework is designed to be compatible with Knative environments. Just build and deploy your container to a Knative environment.
Configure the Functions Framework
You can configure the Functions Framework using command-line flags or environment variables. If you specify both, the environment variable will be ignored.
| Command-line flag | Environment variable | Description | |
|---|---|---|---|
--port |
PORT |
The port on which the Functions Framework listens for requests. Default: 8080 |
|
--target |
FUNCTION_TARGET |
The name of the exported function to be invoked in response to requests. Default: function |
|
--signature-type |
FUNCTION_SIGNATURE_TYPE |
The signature used when writing your function. Controls unmarshalling rules and determines which arguments are used to invoke your function. Default: http; accepted values: http or event or cloudevent |
|
--source |
FUNCTION_SOURCE |
The path to the directory of your function. Default: cwd (the current working directory) |
|
--log-execution-id |
LOG_EXECUTION_ID |
Enables execution IDs in logs, either true or false. When not specified, default to disable. Requires Node.js 13.0.0 or later. |
|
--ignored-routes |
IGNORED_ROUTES |
A route expression for requests that should not be routed the function. An empty 404 response will be returned. This is set to `/favicon.ico | /robots.txtby default forhttp` functions. |
You can set command-line flags in your package.json via the start script.
For example:
"scripts": {
"start": "functions-framework --target=helloWorld"
}Enable Google Cloud Run functions Events
The Functions Framework can unmarshall incoming
Google Cloud Functions event payloads to data and context objects.
These will be passed as arguments to your function when it receives a request.
Note that your function must use the event-style function signature:
exports.helloEvents = (data, context) => {
console.log(data);
console.log(context);
};To enable automatic unmarshalling, set the function signature type to event
using a command-line flag or an environment variable. By default, the HTTP
signature will be used and automatic event unmarshalling will be disabled.
For more details on this signature type, check out the Google Cloud Functions documentation on background functions.
Enable CloudEvents
The Functions Framework can unmarshall incoming
CloudEvents payloads to a cloudevent object.
It will be passed as an argument to your function when it receives a request.
Note that your function must use the cloudevent-style function signature:
const functions = require('@google-cloud/functions-framework');
functions.cloudEvent('helloCloudEvents', (cloudevent) => {
console.log(cloudevent.specversion);
console.log(cloudevent.type);
console.log(cloudevent.source);
console.log(cloudevent.subject);
console.log(cloudevent.id);
console.log(cloudevent.time);
console.log(cloudevent.datacontenttype);
});Advanced Docs
More advanced guides and docs can be found in the docs/ folder.
Contributing
Contributions to this library are welcome and encouraged. See CONTRIBUTING for more information on how to get started.