Knative Functions (func)

The E2E test suite is divided into several categories to verify different aspects of the func CLI and the underlying system:

• Core: Validates basic CRUDL operations: func init (Create), func run (local execution), func deploy (cluster execution/Update), func describe (Read), and func list (List). It also tests remote repository references and templates.
• Metadata: Ensures environment variables, labels, volumes, secrets, and event subscriptions are correctly applied to a Function.
• Remote: Verifies features related to in-cluster builds and remote deployment.
• Podman: Confirms support for the Podman container engine (requires podman and ssh in PATH).
• Matrix: A large-scale test set that checks operations across different language runtimes, templates, and builders. It executes for each language/template/builder permutation. Language-specific scenarios are prefixed with TestMatrix_<Runtime>_* (e.g., TestMatrix_Python_*).
• Config CI: Verifies that GitHub Actions workflows generated by func config ci work correctly using act against a real cluster.

Because Python functions use the ASGI protocol, you must asynchronously iterate through the receive callable to collect the request body. For JSON data, you collect the bytes and then use json.loads().

async def handle(self, scope, receive, send):
    """Process POST requests with JSON data."""
    if scope['method'] == 'POST':
        # Receive request body
        body = b''
        while True:
            message = await receive()
            if message['type'] == 'http.request':
                body += message.get('body', b'')
                if not message.get('more_body', False):
                    break

        # Process JSON data
        import json
        data = json.loads(body)
        
        # ... logic ...

        # Send response
        await send({
            'type': 'http.response.start',
            'status': 200,
            'headers': [[b'content-type', b'application/json']],
        })
        await send({
            'type': 'http.response.body',
            'body': json.dumps(data).encode(),
        })

To create a Python CloudEvents function, you must implement a class that provides a new() method. This method is responsible for returning a function instance.

Beyond the required new() method, your function class can optionally implement the following lifecycle and health methods:

• handle(): Processes incoming CloudEvent requests.
• start(): Used to initialize the function with specific configuration.
• stop(): Used to clean up resources when the function is shutting down.
• alive(): Implements a liveness check.
• ready(): Implements a readiness check.

# See the default implementation in ./function/func.py for reference

# Required method:
def new():
    return FunctionInstance()

# Optional methods:
class FunctionInstance:
    def handle(self, event):
        ...
    def start(self):
        ...
    def stop(self):
        ...
    def alive(self):
        ...
    def ready(self):
        ...

A Node.js function must export a single function from index.js. The handler receives two parameters:

1. context: A Context object containing request metadata.
2. event (optional): The CloudEvent object if the function is triggered by a CloudEvent.

Return Values

• Nothing: Returns 204 No Content.
• JavaScript Type: Returns the value as the response body.
• CloudEvent or Message: Returns the event to the Knative eventing system.
• Object with headers: Sets custom HTTP response headers.
• Object with statusCode: Sets a specific HTTP response code.
• Thrown Error: If an Error object is thrown, you can set err.statusCode to control the response code.

// Basic CloudEvent handler
function handle(context, event) {
  return processCustomer(event.data)
}

function processCustomer(customer) {
  // Return a new CloudEvent to push into the eventing system
  return new CloudEvent({
    source: 'customer.processor',
    type: 'customer.processed'
  })
}

// Returning custom headers
function processCustomerWithHeaders(customer) {
  return { headers: { customerid: customer.id } };
}

// Returning a custom status code
function processCustomerWithStatus(customer) {
  if (customer.restricted) {
    return { statusCode: 451 }
  }
}

// Throwing an error with a status code
function processCustomerWithError(customer) {
  if (customer.restricted) {
    const err = new Error('Unavailable for legal reasons');
    err.statusCode = 451;
    throw err;
  }
}