Lambda Runtime Environments: Python, Node.js, Java, and Go Quiz Quiz

Explore fundamental concepts of Lambda runtime environments focusing on Python, Node.js, Java, and Go. This quiz helps users understand supported features, file structure, and environment selection in serverless computing.

1. Lambda Entry Point

   When using the Python runtime environment, what is the expected name of the handler function in the file 'lambda_function.py'?

   1. entryPoint
   2. mainFunction
   3. lambda_handler
   4. start_lambda

   Explanation: The Python runtime expects the handler function to be named 'lambda_handler' by default. This function serves as the entry point for events. The other options such as 'mainFunction', 'entryPoint', or 'start_lambda' are not recognized as default handler names, which could result in invocation issues.

2. Supported Node.js Versions

   Which of the following is a valid major version of the Node.js runtime often supported by Lambda for deploying functions?

   1. 2
   2. 9
   3. 14
   4. 21

   Explanation: Node.js version 14 is commonly available as a supported major version for Lambda environments. The version '2' is too old and not supported, '21' is not typically available yet, and '9' is outdated. Using unsupported versions may result in errors when deploying your function.

3. Java Handler Signature

   In the Java runtime environment, which method signature is commonly used for a handler that receives input and output as streams?

   1. public void main(String[] args)
   2. public int processEvent(Event e, Context c)
   3. public String lambdaHandler(Request request)
   4. public void handleRequest(InputStream input, OutputStream output, Context context)

   Explanation: The handler for Java Lambda functions can use 'public void handleRequest(InputStream input, OutputStream output, Context context)' to handle streams. The other signatures do not match expected Java Lambda handler patterns. For example, 'main' methods and incorrectly matched argument names are not recognized.

4. Go Function Handler Location

   For Go runtime environments, where should your handler function typically reside?

   1. Inside a handler.json file
   2. In a hidden '.lambda' folder
   3. In the main package
   4. Named as 'server.go'

   Explanation: Go Lambda handlers are typically placed inside the 'main' package, since this is where the entry point is defined. The '.lambda' folder, 'handler.json' file, or requiring a file named 'server.go' are incorrect, as these do not define the structure for Go runtime handlers.

5. Runtime Selection Impact

   What is the effect of choosing the wrong runtime, such as specifying Node.js instead of Python, for your Lambda function?

   1. The function will be silently ignored.
   2. It will automatically translate Python code to Node.js.
   3. Execution time will double but still work.
   4. Your function may fail to execute due to incompatible code.

   Explanation: Selecting an incorrect runtime leads to execution failure, as the underlying environment cannot interpret mismatched code types. There is no automatic code translation, so Node.js cannot run Python code. Execution time will not double; instead, it will simply not work. Functions are not ignored, and errors will be reported.

6. Default File Names

   When deploying with the default Python runtime, what is the standard filename for your Lambda function's code if you do not specify otherwise?

   1. app.go
   2. lambda_function.py
   3. main.js
   4. Handler.java

   Explanation: The default Python filename expected is 'lambda_function.py'. 'main.js' is for JavaScript environments, 'Handler.java' for Java, and 'app.go' is commonly used for Go. Using the wrong filename for your runtime will cause errors on deployment.

7. Dependencies in Node.js Environment

   How are third-party dependencies typically managed in a Node.js Lambda runtime?

   1. Using a package.json file with npm modules
   2. Adding import statements in main.js only
   3. Specifying dependencies in requirements.txt
   4. Listing modules in a go.mod file

   Explanation: Node.js environments rely on 'package.json' files for dependency management and npm modules installation. 'go.mod' is unrelated and used for Go, 'requirements.txt' is for Python, and simply importing packages in 'main.js' does not manage their installation.

8. Environment Variables Usage

   In Lambda runtime environments, how can a Python Lambda function access custom configuration like an API key?

   1. By reading environment variables set for the function
   2. By calling a built-in getConfig() with no arguments
   3. By importing them from handler.js
   4. Through a static config.java file

   Explanation: Environment variables are the recommended way to pass configuration data such as API keys to Lambda functions, including those written in Python. Importing from 'handler.js' or using 'config.java' do not apply to Python. The generic 'getConfig()' function as described does not exist in Python Lambda environments.

9. Handling Output in Go Runtime

   Which type is typically used as the return value for the handler function in a Go Lambda runtime?

   1. None
   2. error
   3. Event
   4. ResponseObject

   Explanation: In Go Lambda functions, handler functions that return an error type can signal execution problems, which is an established convention. 'Event', 'ResponseObject', and 'None' are not the expected return types; only 'error' is recognized for indicating success or failure.

10. Updating Lambda Runtimes

    Why is it important to keep your Lambda runtime environment updated and not use deprecated versions like Python 2.7?

    1. Outdated runtimes may not receive security or maintenance updates.
    2. Using deprecated runtimes lowers costs.
    3. Old runtimes allow unlimited code size.
    4. It improves the speed of your code automatically.

    Explanation: Keeping Lambda environments current ensures you receive relevant security and bug fixes, preventing vulnerabilities. Older runtimes do not enhance performance or reduce costs, nor do they allow unlimited code sizes. Deprecated environments can make your application less secure.