How do refer an existing s3 bucket in my CFN template so that my lambda can use the bucket?

Question

I have a CFN template where in I am creating 2 s3 buckets for the image resizing using CloudFront. the issue is that I want to use an already existing bucket from s3 for these functions. but I get an error that s3 already exists when I provide the resource ARN and other data. how can I resolve this? I tried giving the details ARN name etc and tried deploying but it doesn't work

Answer 1

Something like this would help you:

AWSTemplateFormatVersion: '2010-09-09'
Description: 'CFN template example for referencing existing S3 bucket to lambda'
Parameters:
  myS3Bucket:
    Type: String
    Description: Provide the S3 bucket you want to referece into your lambda.
Resources:
  MyLambdaFunction:
    Type: AWS::Lambda::Function
    Properties:
      Description: A lambda function
      Handler: index.handler
      Runtime: python3.7
      Environment:
        Variables:
          S3_BUCKET: !Ref myS3Bucket