Possible for one resource to reference another? - serverless-framework

Question

I have defined an S3 bucket in my serverless.yml file as follows:
resources:
Resources:
nameOfS3Bucket:
Type: AWS::S3::Bucket
Properties:
BucketName: ${self:custom.stage}-name-of-s3-bucket
AccessControl: Private
What I would like to do now is to reference the arn of the bucket in an IAM role which is also defined as a resource e.g.
resources:
Resources:
# s3 bucket definition removed for brevity
iamRoleName:
Type: AWS::IAM::Role
Properties:
RoleName: ${self:custom.stage}-iam-role-name
AssumeRolePolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: Allow
Principal:
Service:
- lambda.amazonaws.com
Action: sts:AssumeRole
Policies:
- PolicyName: ${self:custom.stage}-iam-role-policy
PolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: Allow
Action: "s3:PutObject"
Resource: *** Need the ARN of the s3 bucket here***
Is there a way to do this?

Answer 1

In my experience, the intrinsic functions in cloudformation work fine inside serverless.yml, but not the yaml short form.
i.e. use Fn::GetAtt over !GetAtt
As long as you use the full syntax for yaml, it should work.
Try this (untested)
resources:
Resources:
nameOfS3Bucket:
Type: AWS::S3::Bucket
Properties:
BucketName: ${self:custom.stage}-name-of-s3-bucket
AccessControl: Private
iamRoleName:
Type: AWS::IAM::Role
Properties:
RoleName: ${self:custom.stage}-iam-role-name
AssumeRolePolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: Allow
Principal:
Service:
- lambda.amazonaws.com
Action: sts:AssumeRole
Policies:
- PolicyName: ${self:custom.stage}-iam-role-policy
PolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: Allow
Action: "s3:PutObject"
Resource:
"Fn::GetAtt": [ nameOfS3Bucket, Arn ]