# \[Solved\] Get a AWS CF resource ID inside Lambda?

**URL:** <https://forum.serverless.com/t/solved-get-a-aws-cf-resource-id-inside-lambda/3313>\
**Category:** Serverless Framework\
**Tags:** aws\
**Created:** [December 12, 2017, 4:11pm UTC](https://forum.serverless.com/t/solved-get-a-aws-cf-resource-id-inside-lambda/3313 "2017-12-12T16:11:35Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![dbeja](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.serverless.com/dbeja/32/498_2.png) [@dbeja](https://forum.serverless.com/u/dbeja)\
**Post date:** [December 12, 2017, 4:11pm UTC](https://forum.serverless.com/t/solved-get-a-aws-cf-resource-id-inside-lambda/3313/1 "2017-12-12T16:11:36Z")

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Hi,

I’m creating some resources on my serverless.yml with cloudformation.  
Is it possible to get the IDs of those resources inside the lambdas so that I don’t need to hard-coded all the IDs of the resources created?

Thanks

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<div class="post-metadata">

**Author:** ![DavidWells](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.serverless.com/davidwells/32/201_2.png) [@DavidWells](https://forum.serverless.com/u/DavidWells)\
**Post date:** [December 12, 2017, 6:47pm UTC](https://forum.serverless.com/t/solved-get-a-aws-cf-resource-id-inside-lambda/3313/2 "2017-12-12T18:47:34Z")

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You can reference cloudformation values like so [https://github.com/DavidWells/serverless-workshop/blob/master/lessons-code-complete/events/dynamodb-streams/serverless.yml#L21](https://github.com/DavidWells/serverless-workshop/blob/master/lessons-code-complete/events/dynamodb-streams/serverless.yml#L21) and pass them in an environment variables

more info here [http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-getatt.html](http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-getatt.html)

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<div class="post-metadata">

**Author:** ![dbeja](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.serverless.com/dbeja/32/498_2.png) [@dbeja](https://forum.serverless.com/u/dbeja)\
**Post date:** [December 13, 2017, 11:14am UTC](https://forum.serverless.com/t/solved-get-a-aws-cf-resource-id-inside-lambda/3313/3 "2017-12-13T11:14:13Z")

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Thanks!

I’m trying to do this with a Cognito Identity Pool but I get the error:

> /Resources/IamRoleLambdaExecution/Properties/Policies/0/PolicyDocument/Statement/2/Resource/0/Fn::Join/1/0/Fn::GetAtt: Resource type AWS::Cognito::IdentityPool does not support  
> attribute {Arn}.

This doesn’t work with a Cognito Identity Pool?

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<div class="post-metadata">

**Author:** ![dbeja](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.serverless.com/dbeja/32/498_2.png) [@dbeja](https://forum.serverless.com/u/dbeja)\
**Post date:** [December 13, 2017, 11:28am UTC](https://forum.serverless.com/t/solved-get-a-aws-cf-resource-id-inside-lambda/3313/4 "2017-12-13T11:28:51Z")

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Ok, now it’s working.

What I did was:

```
  Resource:
    - 'Fn::Join':
      - ''
      -
        - 'arn:aws:cognito-sync:eu-west-2:1111111111:identitypool/'
        - Ref: CognitoIdentityPool
        - '/identity/*/dataset/*'

```

And for environment I did like you have:

```
provider:
  name: aws
  runtime: nodejs6.10
  stage: ${opt:stage, 'dev'}
  environment:
    IDENTITY_POOL_ID: { Ref: CognitoIdentityPool }

```

Thanks!