How do you reuse S3 buckets when deploying Lambdas with Serverless?

Question

Recently we have adopted Serverless to handle the deployment of Lambda functions in our AWS environment, but for every unique function that is deployed, a new S3 bucket is created. This is inefficient and having a single bucket for every stack that Serverless creates would be ideal. Is there any way to do this from within the serverless.yml file? I have attempted the following yml file configurations for resources without any success.

1 - Listing the bucket as a resource to use in the yml 

resources:

  Resources:

    ServerlessBucket:

      Type: AWS::S3::Bucket

      Properties:

        BucketName: serverless-test-bucket

Output:

Serverless: Packaging service...

Serverless: Removing old service versions...

Serverless: Uploading CloudFormation file to S3...

Serverless: Uploading service .zip file to S3...

Serverless: Updating Stack...

Serverless: Checking Stack update progress...

............Serverless: Deployment failed!

 

  Serverless Error ---------------------------------------

 

     An error occurred while provisioning your stack: ServerlessBucket

     - serverless-test-bucket already exists.

2 - Attempting to reference the bucket in the yml

resources:

  Resources:

    ServerlessBucket:

      Type: AWS::S3::Bucket

      Properties:

        Ref: serverless-test-bucket

Output: 

Serverless: Packaging service...

Serverless: Removing old service versions...

Serverless: Uploading CloudFormation file to S3...

Serverless: Uploading service .zip file to S3...

Serverless: Updating Stack...

 

  Serverless Error ---------------------------------------

 

     Template format error: Unresolved resource dependencies

     [serverless-test-bucket] in the

     Resources block of the template

Answer 1

This can be done by adding deploymentBucket as a field inside the serverless.yml file. Below is an example:

provider:

  name: aws

  runtime: python2.7

  stage: dev

  region: us-east-1

  deploymentBucket: bucketName

  iamRoleStatements:

    - Effect: "Allow"

      Action:

      -  "*"

      Resource: "*"