Explore key concepts in cloud function triggers, deployment, and practical applications with this introductory quiz. Enhance your understanding of core serverless features, event handling, and common pitfalls in cloud functions for scalable backend development.
Which type of event can trigger a cloud function to execute automatically without manual intervention?
Explanation: A scheduled time event can trigger a cloud function automatically based on a time schedule, such as every hour or day. Clicking a button in the user interface does not directly trigger backend cloud functions but usually interacts with the frontend. Manual invocation is possible, but the question specifies automatic execution. Saving a file locally only affects the local environment, not cloud function triggers.
Why are environment variables commonly used in cloud functions for serverless backend development?
Explanation: Environment variables are used to store sensitive configuration data, such as API keys, which should not be exposed in source code. Outputting logs is managed through logging tools, not environment variables. Scheduling is handled by specific schedulers or triggers, and deploying static web pages is managed through hosting, not environment variables.
When writing a cloud function that reads data from a database and sends an email, which coding practice ensures the function completes only after all actions are finished?
Explanation: Returning a promise or using async/await ensures the cloud function waits for asynchronous operations, like database queries or sending emails, to complete before finishing. Console logging does not manage function completion. Omitting return statements can result in functions finishing too early. The choice between var and let does not affect asynchronous behavior.
What is meant by a 'cold start' in the context of cloud functions?
Explanation: A 'cold start' refers to the delay experienced when server resources are activated after a period of inactivity, causing the first request to be slower. It is unrelated to authentication issues, physical device weather conditions, or deployment in a 'frozen' state.
If you want a cloud function to process an image each time one is uploaded to cloud storage, which kind of trigger should you use?
Explanation: A storage object finalization trigger executes the function when a file, such as an image, is uploaded successfully to storage. Database and authentication triggers respond to different events. HTTP triggers require direct calls, not automatic execution on file uploads.
When creating a cloud function to accept data from external applications via an API, which trigger should be implemented?
Explanation: An HTTP trigger enables cloud functions to respond to web requests, making it suitable for building APIs. The database trigger responds only to data changes, cloud messaging triggers respond to messaging events, and there is no native 'email trigger.'
What is a recommended practice for managing secrets, such as API keys, in cloud function code?
Explanation: The secure way is storing secrets in environment variables, which keeps them out of version control and source files. Writing keys in plain text or hardcoding them in applications makes them vulnerable. Uploading secrets as public documents exposes them to unauthorized access.
Which statement best describes the lifecycle of data stored in a variable within a single execution of a cloud function?
Explanation: In cloud functions, variables declared inside the function exist only during each individual invocation and are not shared or persisted for later executions. Variables do not remain across invocations or become global. Browser storage is unrelated to server-side cloud function execution.
After updating your cloud function's code, what must you do for the changes to take effect?
Explanation: Deployment is necessary for code changes to take effect because this updates the function on the cloud. Refreshing a browser or rebooting your computer does not affect the deployed code. Sending an email to support is not required for updating functions.
Why is it recommended to keep cloud functions small and focused on a single task?
Explanation: Small, focused functions execute more quickly and are easier to update or debug. Large functions are not necessarily faster; in fact, they may be slower. Hardware keyboard limits are unrelated, and small code does not guarantee zero errors.