The Serverless Framework helps you develop and deploy serverless applications using Google Cloud Functions. It's a CLI that offers structure, automation and best practices out-of-the-box, allowing you to focus on building sophisticated, event-driven, serverless architectures, comprised of Functions and Events.
The Serverless Framework is different than other application frameworks because:
- It manages your code as well as your infrastructure
- It supports multiple languages (Node.js, Python, Java, and more)
Here are the Framework's main concepts and how they pertain to Google Cloud Functions...
A Function is a Google Cloud Function. It's an independent unit of deployment, like a microservice. It's merely code, deployed in the cloud, that is most often written to perform a single job such as:
- Saving a user to the database
- Processing a file in a database
- Performing a scheduled task
You can perform multiple jobs in your code, but we don't recommend doing that without good reason. Separation of concerns is best and the Framework is designed to help you easily develop and deploy Functions, as well as manage lots of them.
Anything that triggers a Google Cloud Function to execute is regarded by the Framework as an Event. Events are platform events on Google Cloud Functions such as:
- An HTTP Trigger (e.g., for a REST API)
- A pubSub event (e.g., run function when message is sent to topic)
- A Storage event (e.g., Image uploaded into bucket)
- And more...
When you define an event for your Google Cloud Function in the Serverless Framework, the Framework will automatically translate the event with its function into a corresponding deployment resource. This way the event is configured so that your functions can listen to it.
A Service is the Framework's unit of organization. You can think of it as a project file, though you can have multiple services for a single application. It's where you define your Functions, the Events that trigger them, and the Resources your Functions use, all in one file by default entitled
serverless.js). It looks like this:
# serverless.yml service: users functions: # Your "Functions" usersCreate: events: # The "Events" that trigger this function - http: create
When you deploy with the Framework by running
serverless deploy, everything in
serverless.yml (or the file specified with the
--config option) is deployed at once.
You can overwrite or extend the functionality of the Framework using Plugins. Every
serverless.yml can contain a
plugins: property, which features multiple plugins.
# serverless.yml plugins: - serverless-plugin-identifier - serverless-another-plugin