# Managing functions

{% hint style="info" %}
This page was generated from content adapted from the [AWS Developer Guide](https://github.com/awsdocs/aws-lambda-developer-guide.git)
{% endhint %}

## Tutorial - Lambda with CLI

* **Note**\
  On Windows, some Bash CLI commands that you commonly use with Lambda (such as `zip`) are not supported by the operating system's built-in terminals. To get a Windows-integrated version of Ubuntu and Bash, [install the Windows Subsystem for Linux](https://docs.microsoft.com/en-us/windows/wsl/install-win10).

## Networking

* **Tip**\
  If your function already includes a VPC configuration from a previous API request, you can send an `UpdateFunctionConfiguration` request without the VPC configuration.
* **Note**\
  Several AWS services offer [VPC endpoints](https://docs.aws.amazon.com/vpc/latest/userguide/vpc-endpoints.html). You can use VPC endpoints to connect to AWS services from within a VPC without internet access.

## Interface VPC endpoints

* **Note**\
  You need to include both the qualified and the unqualified function ARN in the resource.

## File system

* **Note**\
  When you create a file system, you choose a performance mode that can't be changed later. **General purpose** mode has lower latency, and **Max I/O** mode supports a higher maximum throughput and IOPS. For help choosing, see [Amazon EFS performance](https://docs.aws.amazon.com/efs/latest/ug/performance.html) in the *Amazon Elastic File System User Guide*.
* **Note**\
  If your function is not already connected to a VPC, see [Configuring a Lambda function to access resources in a VPC](https://github.com/kevinslin/aws-reference-notes/blob/main/services/aws_lambda/configuration-vpc.md).

## Code signing

* **Note**\
  Functions defined as container images do not support code signing.

## Using layers

* **Note**\
  Make sure that the layers that you add to a function are compatible with the runtime and instruction set architecture of the function.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://awsnotes.dendron.so/serverless/aws-lambda/topics/managing-functions.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.