Update Existing Lambda Function using SAM.

Question

we have multiple lambda functions already created manually, now we wanted to move on SAM. rather then creating any new lambda functions from SAM, we wanted to update existing one. is there any way to move those existing lambda function via SAM, so that we can update and manage those existing lambda function via SAM.

Accepted Answer

As SAM is based on CloudFormation, you can import resources to it.

You'll need to use the CLI for it, as the console doesn't support the import when the template has the Transform section ([reference](https://aws.amazon.com/premiumsupport/knowledge-center/cloudformation-template-resources-error/)).

Here is more information on how to do the import: [Import an existing resource into a stack using the AWS CLI](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/resource-import-existing-stack.html#resource-import-existing-stack-cli).

Check the [overview](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/resource-import.html) of the import process.

Answer

Try exporting the existing Lambda function's SAM template:
Under *Actions > Export Function* then choose "Download AWS SAM File" to download the function SAM template. I think you should be able to tweak it to your needs

Update Existing Lambda Function using SAM.

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