Optimizing networking

Node.js

const http = require('http');
const functions = require('firebase-functions');

// Setting the `keepAlive` option to `true` keeps
// connections open between function invocations
const agent = new http.Agent({keepAlive: true});

exports.function = functions.https.onRequest((request, response) => {
    req = http.request({
        host: '',
        port: 80,
        path: '',
        method: 'GET',
        agent: agent, // Holds the connection open after the first invocation
    }, res => {
        let rawData = '';
        res.setEncoding('utf8');
        res.on('data', chunk => { rawData += chunk; });
        res.on('end', () => {
            response.status(200).send(`Data: ${rawData}`);
        });
    });
    req.on('error', e => {
        response.status(500).send(`Error: ${e.message}`);
    });
    req.end();
});

Python

from firebase_functions import https_fn
import requests

# Create a global HTTP session (which provides connection pooling)
session = requests.Session()

@https_fn.on_request()
def connection_pooling(request):

    # The URL to send the request to
    url = "http://example.com"

    # Process the request
    response = session.get(url)
    response.raise_for_status()
    return https_fn.Response("Success!")
    

This HTTP function uses a connection pool to make HTTP requests. It takes a request object (flask.Request) and returns the response text, or any set of values that can be turned into a Response object using make_response.

node.js

const PubSub = require('@google-cloud/pubsub');
const functions = require('firebase-functions');
const pubsub = PubSub();

exports.function = functions.https.onRequest((req, res) => {
    const topic = pubsub.topic('');

    topic.publish('Test message', err => {
        if (err) {
            res.status(500).send(`Error publishing the message: ${err}`);
        } else {
            res.status(200).send('1 message published');
        }
    });
});

Python

import os

from firebase_functions import https_fn
from google.cloud import pubsub_v1

# from firebase_functions import https_fn
# Create a global Pub/Sub client to avoid unneeded network activity
pubsub = pubsub_v1.PublisherClient()

@https_fn.on_request()
def gcp_api_call(request):

    project = os.getenv("GCP_PROJECT")
    request_json = request.get_json()

    topic_name = request_json["topic"]
    topic_path = pubsub.topic_path(project, topic_name)

    # Process the request
    data = b"Test message"
    pubsub.publish(topic_path, data=data)

    return https_fn.Response("1 message published")
    

This HTTP function uses a cached client library instance to reduce the number of connections required per function invocation. It takes a request object (flask.Request) and returns the response text, or any set of values that can be turned into a Response object using make_response.

The GCP_PROJECT environment variable is set automatically in the Python 3.7 runtime. In later runtimes, make sure to specify it on function deployment. See Configure environment variables.